cloc counts blank lines, comment lines, and physical lines of source code in many programming languages.
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Count Lines of Code

cloc counts blank lines, comment lines, and physical lines of source code in many programming languages.

Latest release: v1.72 (January 14, 2017)

Hosted at since August 2006, cloc began the transition to GitHub in September 2015.

Quick Start ▲

Step 1: Download cloc (several methods, see below).

Step 2: Open a terminal (cmd.exe on Windows).

Step 3: Invoke cloc to count your source files, directories, or archives. The executable name differs depending on whether you use the development source version (cloc), source for a released version ( or a Windows executable (cloc-1.72.exe). On this page, cloc is the generic term used to refer to any of these.

a file

prompt> cloc hello.c
       1 text file.
       1 unique file.
       0 files ignored. v 1.65  T=0.04 s (28.3 files/s, 340.0 lines/s)
Language                     files          blank        comment           code
C                                1              0              7              5

a directory

prompt> cloc gcc-5.2.0/gcc/c
      16 text files.
      15 unique files.
       3 files ignored. v 1.65  T=0.23 s (57.1 files/s, 188914.0 lines/s)
Language                     files          blank        comment           code
C                               10           4680           6621          30812
C/C++ Header                     3             99            286            496
SUM:                            13           4779           6907          31308

an archive

We'll pull cloc's source zip file from GitHub, then count the contents:

prompt> wget

prompt> cloc v 1.65  T=0.07 s (26.8 files/s, 141370.3 lines/s)
Language                     files          blank        comment           code
Perl                             2            725           1103           8713
SUM:                             2            725           1103           8713

each subdirectory of a particular directory

Say you have a directory with three different git-managed projects, Project0, Project1, and Project2. You can use your shell's looping capability to count the code in each. This example uses bash:

prompt> for d in ./*/ ; do (cd "$d" && echo "$d" && cloc --vcs git); done
7 text files.
       7 unique files.                              
       1 file ignored. v 1.71  T=0.02 s (390.2 files/s, 25687.6 lines/s)
Language                     files          blank        comment           code
D                                4             61             32            251
Markdown                         1              9              0             38
make                             1              0              0              4
SUM:                             6             70             32            293
       7 text files.
       7 unique files.                              
       0 files ignored. v 1.71  T=0.02 s (293.0 files/s, 52107.1 lines/s)
Language                     files          blank        comment           code
Go                               7            165            282            798
SUM:                             7            165            282            798
      49 text files.
      47 unique files.                              
      13 files ignored. v 1.71  T=0.10 s (399.5 files/s, 70409.4 lines/s)
Language                     files          blank        comment           code
Python                          33           1226           1026           3017
C                                4            327            337            888
Markdown                         1             11              0             28
YAML                             1              0              2             12
SUM:                            39           1564           1365           3945

Overview ▲

[Translations: Arabic, Armenian, Belarussian, Bulgarian, Russian, Serbo-Croatian, Romanian, Slovakian, Tamil, Ukrainian ]

cloc counts blank lines, comment lines, and physical lines of source code in many programming languages. Given two versions of a code base, cloc can compute differences in blank, comment, and source lines. It is written entirely in Perl with no dependencies outside the standard distribution of Perl v5.6 and higher (code from some external modules is embedded within cloc) and so is quite portable. cloc is known to run on many flavors of Linux, FreeBSD, NetBSD, OpenBSD, Mac OS X, AIX, HP-UX, Solaris, IRIX, z/OS, and Windows. (To run the Perl source version of cloc on Windows one needs ActiveState Perl 5.6.1 or higher, Strawberry Perl, Cygwin, or MobaXTerm with the Perl plug-in installed. Alternatively one can use the Windows binary of cloc generated with PAR::Packer to run on Windows computers that have neither Perl nor Cygwin.)

cloc contains code from David Wheeler's SLOCCount, Damian Conway and Abigail's Perl module Regexp::Common, Sean M. Burke's Perl module Win32::Autoglob, and Tye McQueen's Perl module Algorithm::Diff. Language scale factors were derived from Mayes Consulting, LLC web site

Install via package manager

Depending your operating system, one of these installation methods may work for you:

npm install -g cloc                    #
sudo apt-get install cloc              # Debian, Ubuntu
sudo yum install cloc                  # Red Hat, Fedora
sudo dnf install cloc                  # Fedora 22 or later
sudo pacman -S cloc                    # Arch
emerge -av dev-util/cloc               # Gentoo
sudo pkg install cloc                  # FreeBSD
sudo port install cloc                 # Mac OS X with MacPorts
brew install cloc                      # Mac OS X with Homebrew
choco install cloc                     # Windows with Chocolatey

Note: I don't control any of these packages. If you encounter a bug in cloc using one of the above packages, try with cloc pulled from the latest stable release here on github (link follows below) before submitting a problem report.

Stable release

Development version

License ▲

cloc is licensed under the GNU General Public License, v 2, excluding portions which are copied from other sources. Code copied from the Regexp::Common, Win32::Autoglob, and Algorithm::Diff Perl modules is subject to the Artistic License.

Why Use cloc? ▲

cloc has many features that make it easy to use, thorough, extensible, and portable:

  1. Exists as a single, self-contained file that requires minimal installation effort---just download the file and run it.
  2. Can read language comment definitions from a file and thus potentially work with computer languages that do not yet exist.
  3. Allows results from multiple runs to be summed together by language and by project.
  4. Can produce results in a variety of formats: plain text, SQL, JSON, XML, YAML, comma separated values.
  5. Can count code within compressed archives (tar balls, Zip files, Java .ear files).
  6. Has numerous troubleshooting options.
  7. Handles file and directory names with spaces and other unusual characters.
  8. Has no dependencies outside the standard Perl distribution.
  9. Runs on Linux, FreeBSD, NetBSD, OpenBSD, Mac OS X, AIX, HP-UX, Solaris, IRIX, and z/OS systems that have Perl 5.6 or higher. The source version runs on Windows with either ActiveState Perl, Strawberry Perl, Cygwin, or MobaXTerm+Perl plugin. Alternatively on Windows one can run the Windows binary which has no dependencies.

Other Counters ▲

If cloc does not suit your needs here are other freely available counters to consider:

Other references:

Regexp::Common, Digest::MD5, Win32::Autoglob, Algorithm::Diff

Although cloc does not need Perl modules outside those found in the standard distribution, cloc does rely on a few external modules. Code from three of these external modules--Regexp::Common, Win32::Autoglob, and Algorithm::Diff--is embedded within cloc. A fourth module, Digest::MD5, is used only if it is available. If cloc finds Regexp::Common or Algorithm::Diff installed locally it will use those installation. If it doesn't, cloc will install the parts of Regexp::Common and/or Algorithm:Diff it needs to temporary directories that are created at the start of a cloc run then removed when the run is complete. The necessary code from Regexp::Common v2.120 and Algorithm::Diff v1.1902 are embedded within the cloc source code (see subroutines Install_Regexp_Common() and Install_Algorithm_Diff() ). Only three lines are needed from Win32::Autoglob and these are included directly in cloc.

Additionally, cloc will use Digest::MD5 to validate uniqueness among input files if Digest::MD5 is installed locally. If Digest::MD5 is not found the file uniqueness check is skipped.

The Windows binary is built on a computer that has both Regexp::Common and Digest::MD5 installed locally.

Building a Windows Executable ▲

The two most recent Windows downloads, cloc-1.70.exe and cloc-1.72.exe, were built with PAR::Packer and Strawberry Perl on an Amazon Web Services t2.micro instance running 32 bit Microsoft Windows Server 2008.

The cloc-1.66.exe executable was built with PAR::Packer on a 32 bit Windows 7 VirtualBox image pulled from and running on an Ubuntu 15.10 host. The virtual machine ran Strawberry Perl version 5.22.1. Windows executables of cloc versions 1.60 and earlier were built with perl2exe on a 32 bit Windows XP computer. A small modification was made to the cloc source code before passing it to perl2exe; lines 87 and 88 were uncommented:

85  # Uncomment next two lines when building Windows executable with perl2exe
86  # or if running on a system that already has Regexp::Common.
87  #use Regexp::Common;
88  #$HAVE_Rexexp_Common = 1;

Is the Windows executable safe to run? Does it have malware?

Ideally, no one would need the Windows executable because they have a Perl interpreter installed on their machines and can run the cloc source file. On centrally-managed corporate Windows machines, however, this this may be difficult or impossible.

The Windows executable distributed with cloc is provided as a best-effort of a virus and malware-free .exe. You are encouraged to run your own virus scanners against the executable and also check sites such . The entries for cloc 1.66 and 1.68 are:

cloc 1.68 exe:

cloc 1.66 exe:

Why is the Windows executable so large?

Windows executables of cloc versions 1.60 and earlier, created with perl2exe as noted above, are about 1.6 MB, while versions 1.62 and 1.54, created with PAR::Packer, are 11 MB. Version 1.66, built with a newer version of PAR::Packer, is about 5.5 MB. Why are the PAR::Packer, executables so much larger than those built with perl2exe? My theory is that perl2exe uses smarter tree pruning logic than PAR::Packer, but that's pure speculation.

Create your own executable

The most robust option for creating a Windows executable of cloc is to use ActiveState's Perl Development Kit. It includes a utility, perlapp, which can build stand-alone Windows, Mac, and Linux binaries of Perl source code.

perl2exe will also do the trick. If you do have `perl2exe, modify lines 84-87 in the cloc source code for a minor code modification that is necessary to make a cloc Windows executable.

Otherwise, to build a Windows executable with pp from PAR::Packer, first install a Windows-based Perl distribution (for example Strawberry Perl or ActivePerl) following their instructions. Next, open a command prompt, aka a DOS window and install the PAR::Packer module. Finally, invoke the newly installed pp command with the cloc source code to create an .exe file:

C:> cpan -i Digest::MD5
C:> cpan -i Regexp::Common
C:> cpan -i Algorithm::Diff
C:> cpan -i PAR::Packer
C:> pp -M Digest::MD5 -c -x -o cloc-1.68.exe cloc

A variation on the instructions above is if you installed the portable version of Strawberry Perl, you will need to run portableshell.bat first to properly set up your environment.

Basic Use ▲

cloc is a command line program that takes file, directory, and/or archive names as inputs. Here's an example of running cloc against the Perl v5.22.0 source distribution:

prompt> cloc perl-5.22.0.tar.gz
    5605 text files.
    5386 unique files.
    2176 files ignored. v 1.65  T=25.49 s (134.7 files/s, 51980.3 lines/s)
Language                         files          blank        comment           code
Perl                              2892         136396         184362         536445
C                                  130          24676          33684         155648
C/C++ Header                       148           9766          16569         147858
Bourne Shell                       112           4044           6796          42668
Pascal                               8            458           1603           8592
XML                                 33            142              0           2410
YAML                                49             20             15           2078
C++                                 10            313            277           2033
make                                 4            426            488           1986
Prolog                              12            438              2           1146
JSON                                14              1              0           1037
yacc                                 1             85             76            998
Windows Message File                 1            102             11            489
DOS Batch                           14             92             41            389
Windows Resource File                3             10              0             85
D                                    1              5              7              8
Lisp                                 2              0              3              4
SUM:                              3434         176974         243934         903874

To run cloc on Windows computers, one must first open up a command (aka DOS) window and invoke cloc.exe from the command line there.

Options ▲

prompt> cloc --help

Usage: cloc [options]  | SET 1 SET 2 | 

 Count, or compute differences of, physical lines of source code in the
 given files (may be archives such as compressed tarballs or zip files)
 and/or recursively below the given directories.

 Input Options
   --extract-with=CMD        This option is only needed if cloc is unable
                             to figure out how to extract the contents of
                             the input file(s) by itself.
                             Use CMD to extract binary archive files (e.g.:
                             .tar.gz, .zip, .Z).  Use the literal '>FILE<' as
                             a stand-in for the actual file(s) to be
                             extracted.  For example, to count lines of code
                             in the input files
                                gcc-4.2.tar.gz  perl-5.8.8.tar.gz
                             on Unix use
                               --extract-with='gzip -dc >FILE< | tar xf -'
                             or, if you have GNU tar,
                               --extract-with='tar zxf >FILE<'
                             and on Windows use, for example:
                               --extract-with="\"c:\Program Files\WinZip\WinZip32.exe\" -e -o >FILE< ."
                             (if WinZip is installed there).
   --list-file=FILE          Take the list of file and/or directory names to
                             process from FILE, which has one file/directory
                             name per line.  Only exact matches are counted;
                             relative path names will be resolved starting from
                             the directory where cloc is invoked.
                             See also --exclude-list-file.
   --vcs=VCS                 Invoke a system call to VCS to obtain a list of
                             files to work on.  If VCS is 'git', then will
                             invoke 'git ls-files' to get a file list and
                             'git submodule status' to get a list of submodules
                             whose contents will be ignored.  If VCS is 'svn'
                             then will invoke 'svn list -R'.  The primary benefit
                             is that cloc will then skip files explicitly
                             excluded by the versioning tool in question,
                             ie, those in .gitignore or have the svn:ignore
                             Alternatively VCS may be any system command
                             that generates a list of files.
                             Note:  cloc must be in a directory which can read
                             the files as they are returned by VCS.  cloc will
                             not download files from remote repositories.
                             'svn list -R' may refer to a remote repository
                             to obtain file names (and therefore may require
                             authentication to the remote repository), but
                             the files themselves must be local.
   --unicode                 Check binary files to see if they contain Unicode
                             expanded ASCII text.  This causes performance to
                             drop noticeably.

 Processing Options
   --autoconf                Count .in files (as processed by GNU autoconf) of
                             recognized languages.
   --by-file                 Report results for every source file encountered.
   --by-file-by-lang         Report results for every source file encountered
                             in addition to reporting by language.
   --count-and-diff SET1 SET2
                             First perform direct code counts of source file(s)
                             of SET1 and SET2 separately, then perform a diff
                             of these.  Inputs may be pairs of files, directories,
                             or archives.  See also --diff, --diff-alignment,
                             --diff-timeout, --ignore-case, --ignore-whitespace.
   --diff SET1 SET2          Compute differences in code and comments between
                             source file(s) of SET1 and SET2.  The inputs
                             may be pairs of files, directories, or archives.
                             Use --diff-alignment to generate a list showing
                             which file pairs where compared.  See also
                             --count-and-diff, --diff-alignment, --diff-timeout,
                             --ignore-case, --ignore-whitespace.
   --diff-timeout N          Ignore files which take more than N seconds
                             to process.  Default is 10 seconds.
                             (Large files with many repeated lines can cause
                             Algorithm::Diff::sdiff() to take hours.)
   --follow-links            [Unix only] Follow symbolic links to directories
                             (sym links to files are always followed).
                             Process all files that have a EXT extension
                             with the counter for language LANG.  For
                             example, to count all .f files with the
                             Fortran 90 counter (which expects files to
                             end with .f90) instead of the default Fortran 77
                             counter, use
                               --force-lang="Fortran 90",f
                             If EXT is omitted, every file will be counted
                             with the LANG counter.  This option can be
                             specified multiple times (but that is only
                             useful when EXT is given each time).
                             See also --script-lang, --lang-no-ext.
   --force-lang-def=FILE     Load language processing filters from FILE,
                             then use these filters instead of the built-in
                             filters.  Note:  languages which map to the same
                             file extension (for example:
                             MATLAB/Mathematica/Objective C/MUMPS/Mercury;
                             Pascal/PHP; Lisp/OpenCL; Lisp/Julia; Perl/Prolog)
                             will be ignored as these require additional
                             processing that is not expressed in language
                             definition files.  Use --read-lang-def to define
                             new language filters without replacing built-in
                             filters (see also --write-lang-def).
   --ignore-whitespace       Ignore horizontal white space when comparing files
                             with --diff.  See also --ignore-case.
   --ignore-case             Ignore changes in case; consider upper- and lower-
                             case letters equivalent when comparing files with
                             --diff.  See also --ignore-whitespace.
   --lang-no-ext=LANG        Count files without extensions using the LANG
                             counter.  This option overrides internal logic
                             for files without extensions (where such files
                             are checked against known scripting languages
                             by examining the first line for #!).  See also
                             --force-lang, --script-lang.
   --max-file-size=MB        Skip files larger than MB megabytes when
                             traversing directories.  By default, MB=100.
                             cloc's memory requirement is roughly twenty times
                             larger than the largest file so running with
                             files larger than 100 MB on a computer with less
                             than 2 GB of memory will cause problems.
                             Note:  this check does not apply to files
                             explicitly passed as command line arguments.
   --original-dir            [Only effective in combination with
                             --strip-comments]  Write the stripped files
                             to the same directory as the original files.
   --read-binary-files       Process binary files in addition to text files.
                             This is usually a bad idea and should only be
                             attempted with text files that have embedded
                             binary data.
   --read-lang-def=FILE      Load new language processing filters from FILE
                             and merge them with those already known to cloc.
                             If FILE defines a language cloc already knows
                             about, cloc's definition will take precedence.
                             Use --force-lang-def to over-ride cloc's
                             definitions (see also --write-lang-def ).
   --script-lang=LANG,S      Process all files that invoke S as a #!
                             scripting language with the counter for language
                             LANG.  For example, files that begin with
                             will be counted with the Perl counter by using
                             The language name is case insensitive but the
                             name of the script language executable, S,
                             must have the right case.  This option can be
                             specified multiple times.  See also --force-lang,
   --sdir=DIR                Use DIR as the scratch directory instead of
                             letting File::Temp chose the location.  Files
                             written to this location are not removed at
                             the end of the run (as they are with File::Temp).
   --skip-uniqueness         Skip the file uniqueness check.  This will give
                             a performance boost at the expense of counting
                             files with identical contents multiple times
                             (if such duplicates exist).
   --stdin-name=FILE         Give a file name to use to determine the language
                             for standard input.  (Use - as the input name to
                             receive source code via STDIN.)
   --strip-comments=EXT      For each file processed, write to the current
                             directory a version of the file which has blank
                             lines and comments removed.  The name of each
                             stripped file is the original file name with
                             .EXT appended to it.  It is written to the
                             current directory unless --original-dir is on.
   --sum-reports             Input arguments are report files previously
                             created with the --report-file option.  Makes
                             a cumulative set of results containing the
                             sum of data from the individual report files.
   --unix                    Override the operating system autodetection
                             logic and run in UNIX mode.  See also
                             --windows, --show-os.
   --use-sloccount           If SLOCCount is installed, use its compiled
                             executables c_count, java_count, pascal_count,
                             php_count, and xml_count instead of cloc's
                             counters.  SLOCCount's compiled counters are
                             substantially faster than cloc's and may give
                             a performance improvement when counting projects
                             with large files.  However, these cloc-specific
                             features will not be available: --diff,
                             --count-and-diff, --strip-comments, --unicode.
   --windows                 Override the operating system autodetection
                             logic and run in Microsoft Windows mode.
                             See also --unix, --show-os.

 Filter Options
   --exclude-dir=D1[,D2,]    Exclude the given comma separated directories
                             D1, D2, D3, et cetera, from being scanned.  For
                             example  --exclude-dir=.cache,test  will skip
                             all files and subdirectories that have /.cache/
                             or /test/ as their parent directory.
                             Directories named .bzr, .cvs, .hg, .git, and
                             .svn are always excluded.
                             This option only works with individual directory
                             names so including file path separators is not
                             allowed.  Use --fullpath and --not-match-d=REGEX
                             to supply a regex matching multiple subdirectories.
                             Do not count files having the given file name
   --exclude-lang=L1[,L2,]   Exclude the given comma separated languages
                             L1, L2, L3, et cetera, from being counted.
   --exclude-list-file=FILE  Ignore files and/or directories whose names
                             appear in FILE.  FILE should have one file
                             name per line.  Only exact matches are ignored;
                             relative path names will be resolved starting from
                             the directory where cloc is invoked.
                             See also --list-file.
   --fullpath                Modifies the behavior of --match-f, --not-match-f,
                             and --not-match-d to include the file's path
                             in the regex, not just the file's basename.
                             (This does not expand each file to include its
                             absolute path, instead it uses as much of
                             the path as is passed in to cloc.)
                             Note:  --match-d always looks at the full
                             path and therefore is unaffected by --fullpath.
   --include-lang=L1[,L2,]   Count only the given comma separated languages
                             L1, L2, L3, et cetera.
   --match-d=REGEX           Only count files in directories matching the Perl
                             regex.  For example
                             only counts files in directories containing
                             /src/ or /include/.  Unlike --not-match-d,
                             --match-f, and --not-match-f, --match-d always
                             compares the fully qualified path against the regex.
   --not-match-d=REGEX       Count all files except those in directories
                             matching the Perl regex.  Only the trailing
                             directory name is compared, for example, when
                             counting in /usr/local/lib, only 'lib' is
                             compared to the regex.
                             Add --fullpath to compare parent directories to
                             the regex.
                             Do not include file path separators at the beginning
                             or end of the regex.
   --match-f=REGEX           Only count files whose basenames match the Perl
                             regex.  For example
                             only counts files that start with Widget or widget.
                             Add --fullpath to include parent directories
                             in the regex instead of just the basename.
   --not-match-f=REGEX       Count all files except those whose basenames
                             match the Perl regex.  Add --fullpath to include
                             parent directories in the regex instead of just
                             the basename.
   --skip-archive=REGEX      Ignore files that end with the given Perl regular
                             expression.  For example, if given
                             the code will skip files that end with .zip,
                             .tar, .tar.gz, .tar.Z, .tar.bz2, .tar.xz, and
   --skip-win-hidden         On Windows, ignore hidden files.

 Debug Options
   --categorized=FILE        Save names of categorized files to FILE.
   --counted=FILE            Save names of processed source files to FILE.
   --diff-alignment=FILE     Write to FILE a list of files and file pairs
                             showing which files were added, removed, and/or
                             compared during a run with --diff.  This switch
                             forces the --diff mode on.
   --explain=LANG            Print the filters used to remove comments for
                             language LANG and exit.  In some cases the
                             filters refer to Perl subroutines rather than
                             regular expressions.  An examination of the
                             source code may be needed for further explanation.
   --help                    Print this usage information and exit.
   --found=FILE              Save names of every file found to FILE.
   --ignored=FILE            Save names of ignored files and the reason they
                             were ignored to FILE.
   --print-filter-stages     Print processed source code before and after
                             each filter is applied.
   --show-ext[=EXT]          Print information about all known (or just the
                             given) file extensions and exit.
   --show-lang[=LANG]        Print information about all known (or just the
                             given) languages and exit.
   --show-os                 Print the value of the operating system mode
                             and exit.  See also --unix, --windows.
   -v[=N]                    Verbose switch (optional numeric value).
   -verbose[=N]              Long form of -v.
   --version                 Print the version of this program and exit.
   --write-lang-def=FILE     Writes to FILE the language processing filters
                             then exits.  Useful as a first step to creating
                             custom language definitions (see also
                             --force-lang-def, --read-lang-def).

 Output Options
   --3                       Print third-generation language output.
                             (This option can cause report summation to fail
                             if some reports were produced with this option
                             while others were produced without it.)
   --by-percent  X           Instead of comment and blank line counts, show
                             these values as percentages based on the value
                             of X in the denominator:
                                X = 'c'   -> # lines of code
                                X = 'cm'  -> # lines of code + comments
                                X = 'cb'  -> # lines of code + blanks
                                X = 'cmb' -> # lines of code + comments + blanks
                             For example, if using method 'c' and your code
                             has twice as many lines of comments as lines
                             of code, the value in the comment column will
                             be 200%.  The code column remains a line count.
   --csv                     Write the results as comma separated values.
   --csv-delimiter=C         Use the character C as the delimiter for comma
                             separated files instead of ,.  This switch forces
   --json                    Write the results as JavaScript Object Notation
                             (JSON) formatted output.
   --md                      Write the results as Markdown-formatted text.
   --out=FILE                Synonym for --report-file=FILE.
   --progress-rate=N         Show progress update after every N files are
                             processed (default N=100).  Set N to 0 to
                             suppress progress output (useful when redirecting
                             output to STDOUT).
   --quiet                   Suppress all information messages except for
                             the final report.
   --report-file=FILE        Write the results to FILE instead of STDOUT.
   --sql=FILE                Write results as SQL create and insert statements
                             which can be read by a database program such as
                             SQLite.  If FILE is -, output is sent to STDOUT.
   --sql-append              Append SQL insert statements to the file specified
                             by --sql and do not generate table creation
                             statements.  Only valid with the --sql option.
   --sql-project=NAME        Use NAME as the project identifier for the
                             current run.  Only valid with the --sql option.
   --sql-style=STYLE         Write SQL statements in the given style instead
                             of the default SQLite format.  Currently, the
                             only style option is Oracle.
   --sum-one                 For plain text reports, show the SUM: output line
                             even if only one input file is processed.
   --xml                     Write the results in XML.
   --xsl=FILE                Reference FILE as an XSL stylesheet within
                             the XML output.  If FILE is 1 (numeric one),
                             writes a default stylesheet, cloc.xsl (or
                             cloc-diff.xsl if --diff is also given).
                             This switch forces --xml on.
   --yaml                    Write the results in YAML.

Recognized Languages ▲

prompt> cloc --show-lang

ABAP                       (abap)
ActionScript               (as)
Ada                        (ada, adb, ads, pad)
ADSO/IDSM                  (adso)
AMPLE                      (ample, dofile, startup)
Ant                        (build.xml, build.xml)
Antlr                      (g)
Apex Trigger               (trigger)
Arduino Sketch             (ino, pde)
ASP                        (asa, asp)
ASP.Net                    (asax, ascx, asmx, aspx, master, sitemap, webinfo)
AspectJ                    (aj)
Assembly                   (asm, S, s)
AutoHotkey                 (ahk)
awk                        (awk)
Blade                      (blade.php)
Bourne Again Shell         (bash)
Bourne Shell               (sh)
builder                    (xml.builder)
C                          (c, ec, pgc)
C Shell                    (csh, tcsh)
C#                         (cs)
C++                        (C, c++, cc, cpp, cxx, pcc)
C/C++ Header               (h, H, hh, hpp, hxx)
CCS                        (ccs)
Clean                      (dcl, icl)
Clojure                    (clj)
ClojureC                   (cljc)
ClojureScript              (cljs)
CMake                      (cmake, CMakeLists.txt)
COBOL                      (CBL, cbl, cob, COB)
CoffeeScript               (coffee)
ColdFusion                 (cfm)
ColdFusion CFScript        (cfc)
Coq                        (v)
Crystal                    (cr)
CSON                       (cson)
CSS                        (css)
CUDA                       (cu, cuh)
Cython                     (pyx)
D                          (d)
DAL                        (da)
Dart                       (dart)
diff                       (diff)
DITA                       (dita)
DOORS Extension Language   (dxl)
DOS Batch                  (BAT, bat, btm, BTM, cmd, CMD)
DTD                        (dtd)
dtrace                     (d)
ECPP                       (ecpp)
EEx                        (eex)
Elixir                     (ex, exs)
Elm                        (elm)
ERB                        (erb, ERB)
Erlang                     (erl, hrl)
Expect                     (exp)
F#                         (fsi, fs, fs)
Focus                      (focexec)
Forth                      (4th, e4, f83, fb, forth, fpm, fr, frt, ft, fth, rx, fs, f, for)
Fortran 77                 (F, f77, F77, FOR, ftn, FTN, pfo, f, for)
Fortran 90                 (f90, F90)
Fortran 95                 (f95, F95)
Freemarker Template        (ftl)
GDScript                   (gd)
Glade                      (glade, ui)
GLSL                       (comp, frag, geom, glsl, tesc, tese, vert)
Go                         (go)
Grails                     (gsp)
Groovy                     (gant, gradle, groovy)
Haml                       (haml)
Handlebars                 (handlebars, hbs)
Harbour                    (hb)
Haskell                    (hs, lhs)
Haxe                       (hx)
HLSL                       (cg, cginc, hlsl, shader)
HTML                       (htm, html)
IDL                        (idl, pro)
INI                        (ini)
InstallShield              (ism)
Java                       (java)
JavaScript                 (es6, js)
JavaServer Faces           (jsf)
JCL                        (jcl)
JSON                       (json)
JSP                        (jsp, jspf)
JSX                        (jsx)
Julia                      (jl)
Kermit                     (ksc)
Korn Shell                 (ksh)
Kotlin                     (kt, kts)
LESS                       (less)
lex                        (l)
LFE                        (lfe)
liquid                     (liquid)
Lisp                       (asd, el, lisp, lsp, sc, cl, jl)
LiveLink OScript           (oscript)
Logtalk                    (lgt, logtalk)
Lua                        (lua)
m4                         (ac, m4)
make                       (am, Gnumakefile, gnumakefile, makefile, Makefile, mk)
Mako                       (mako)
Markdown                   (md)
Mathematica                (mt, wl, wlt, m)
MATLAB                     (m)
Maven                      (pom, pom.xml)
Modula3                    (i3, ig, m3, mg)
MSBuild script             (csproj, vbproj, vcproj, wdproj, wixproj)
MUMPS                      (mps, m)
Mustache                   (mustache)
MXML                       (mxml)
NAnt script                (build)
NASTRAN DMAP               (dmap)
Nemerle                    (n)
Nim                        (nim)
Objective C                (m)
Objective C++              (mm)
OCaml                      (ml, mli, mll, mly)
OpenCL                     (cl)
Oracle Forms               (fmt)
Oracle Reports             (rex)
Pascal                     (dpr, p, pas)
Pascal/Puppet              (pp)
Patran Command Language    (pcl, ses)
Perl                       (perl, plh, plx, pm, pm6, pl)
PHP                        (php, php3, php4, php5, phtml)
PHP/Pascal                 (inc)
Pig Latin                  (pig)
PL/I                       (pl1)
PO File                    (po)
PowerBuilder               (sra, srf, srm, srs, sru, srw)
PowerShell                 (ps1, psd1, psm1)
Prolog                     (P, pl, pro)
Protocol Buffers           (proto)
Pug                        (pug)
PureScript                 (purs)
Python                     (py)
QML                        (qml)
Qt                         (ui)
Qt Linguist                (ts)
Qt Project                 (pro)
R                          (R, r)
Racket                     (rkt, rktl, sch, scm, scrbl, ss)
RapydScript                (pyj)
Razor                      (cshtml)
Rexx                       (rexx)
RobotFramework             (robot, tsv)
Ruby                       (rake, rb)
Ruby HTML                  (rhtml)
Rust                       (rs)
SAS                        (sas)
Sass                       (sass, scss)
Scala                      (scala)
sed                        (sed)
SKILL                      (il)
SKILL++                    (ils)
Slice                      (ice)
Slim                       (slim)
Smarty                     (smarty, tpl)
Softbridge Basic           (SBL, sbl)
Specman e                  (e)
SQL                        (psql, sql, SQL)
SQL Data                   (data.sql)
SQL Stored Procedure       (spc.sql, spoc.sql, sproc.sql, udf.sql)
Standard ML                (fun, sig, sml)
Stylus                     (styl)
Swift                      (swift)
Tcl/Tk                     (itk, tcl, tk)
Teamcenter met             (met)
Teamcenter mth             (mth)
TeX                        (bst, dtx, sty, tex)
TITAN Project File Information (tpd)
Titanium Style Sheet       (tss)
TTCN                       (ttcn, ttcn2, ttcn3, ttcnpp)
Twig                       (twig)
TypeScript                 (tsx, ts)
Unity-Prefab               (mat, prefab)
Vala                       (vala)
Vala Header                (vapi)
Velocity Template Language (vm)
Verilog-SystemVerilog      (sv, svh, v)
VHDL                       (VHD, vhd, VHDL, vhdl)
vim script                 (vim)
Visual Basic               (bas, cls, ctl, dsr, frm, VB, vb, vba, VBA, VBS, vbs)
Visual Fox Pro             (sca, SCA)
Visualforce Component      (component)
Visualforce Page           (page)
Vuejs Component            (vue)
Windows Message File       (mc)
Windows Module Definition  (def)
Windows Resource File      (rc, rc2)
WiX include                (wxi)
WiX source                 (wxs)
WiX string localization    (wxl)
XAML                       (xaml)
xBase                      (prg)
xBase Header               (ch)
XHTML                      (xhtml)
XMI                        (XMI, xmi)
XML                        (xml, XML)
XQuery                     (xq, xquery)
XSD                        (XSD, xsd)
XSLT                       (XSL, xsl, xslt, XSLT)
yacc                       (y)
YAML                       (yaml, yml)
zsh                        (zsh)

The above list can be customized by reading language definitions from a file with the --read-lang-def or --force-lang-def options.

These file extensions map to multiple languages:

  • .cl files could be Lisp or OpenCL
  • .d files could be D or dtrace
  • .f or .for files could be Fortran or Forth
  • .fs files could be Forth or F#
  • .inc files could be PHP or Pascal
  • .jl files could be Lisp or Julia
  • .m files could be MATLAB, Mathematica, Mercury, MUMPS, or Objective C
  • .pl files could be Perl or Prolog
  • .pp files could be Pascal or Puppet
  • .pro files could be IDL, Prolog, or a Qt Project
  • .ts files could be TypeScript or Qt Linguist
  • .v files Coq or Verilog/SystemVerilog

cloc has subroutines that attempt to identify the correct language based on the file's contents for these special cases. Language identification accuracy is a function of how much code the file contains; .m files with just one or two lines for example, seldom have enough information to correctly distinguish between MATLAB, Mercury, MUMPS, or Objective C.

Languages with file extension collisions are difficult to customize with --read-lang-def or --force-lang-def as they have no mechanism to identify languages with common extensions. In this situation one must modify the cloc source code.

How It Works ▲

cloc's method of operation resembles SLOCCount's: First, create a list of files to consider. Next, attempt to determine whether or not found files contain recognized computer language source code. Finally, for files identified as source files, invoke language-specific routines to count the number of source lines.

A more detailed description:

  1. If the input file is an archive (such as a .tar.gz or .zip file), create a temporary directory and expand the archive there using a system call to an appropriate underlying utility (tar, bzip2, unzip, etc) then add this temporary directory as one of the inputs. (This works more reliably on Unix than on Windows.)
  2. Use File::Find to recursively descend the input directories and make a list of candidate file names. Ignore binary and zero-sized files.
  3. Make sure the files in the candidate list have unique contents (first by comparing file sizes, then, for similarly sized files, compare MD5 hashes of the file contents with Digest::MD5). For each set of identical files, remove all but the first copy, as determined by a lexical sort, of identical files from the set. The removed files are not included in the report. (The --skip-uniqueness switch disables the uniqueness tests and forces all copies of files to be included in the report.) See also the --ignored= switch to see which files were ignored and why.
  4. Scan the candidate file list for file extensions which cloc associates with programming languages (see the --show-lang and --show-ext options). Files which match are classified as containing source code for that language. Each file without an extensions is opened and its first line read to see if it is a Unix shell script (anything that begins with #!). If it is shell script, the file is classified by that scripting language (if the language is recognized). If the file does not have a recognized extension or is not a recognzied scripting language, the file is ignored.
  5. All remaining files in the candidate list should now be source files for known programming languages. For each of these files:

    1. Read the entire file into memory.
    2. Count the number of lines (= Loriginal).
    3. Remove blank lines, then count again (= Lnon_blank).
    4. Loop over the comment filters defined for this language. (For example, C++ has two filters: (1) remove lines that start with optional whitespace followed by // and (2) remove text between /* and */) Apply each filter to the code to remove comments. Count the left over lines (= Lcode).
    5. Save the counts for this language:
      • blank lines = Loriginal - Lnon_blank
      • comment lines = Lnon_blank - Lcode
      • code lines = Lcode

The options modify the algorithm slightly. The --read-lang-def option for example allows the user to read definitions of comment filters, known file extensions, and known scripting languages from a file. The code for this option is processed between Steps 2 and 3.

Advanced Use ▲

Remove Comments from Source Code ▲

How can you tell if cloc correctly identifies comments? One way to convince yourself cloc is doing the right thing is to use its --strip-comments option to remove comments and blank lines from files, then compare the stripped-down files to originals.

Let's try this out with the SQLite amalgamation, a C file containing all code needed to build the SQLite library along with a header file:

prompt> tar zxf sqlite-amalgamation-3.5.6.tar.gz
prompt> cd sqlite-3.5.6/
prompt> cloc --strip-comments=nc sqlite.c
       1 text file.
       1 unique file.
       0 files ignored. v 1.03  T=1.0 s (1.0 files/s, 82895.0 lines/s)
Language          files     blank   comment      code    scale   3rd gen. equiv
C                     1      5167     26827     50901 x   0.77 =       39193.77

The extension argument given to --strip-comments is arbitrary; here nc was used as an abbreviation for "no comments".

cloc removed over 31,000 lines from the file:

prompt> wc -l sqlite3.c
  82895 sqlite3.c
 133796 total
prompt> echo "82895 - 50901" | bc

We can now compare the original file, sqlite3.c and the one stripped of comments, with tools like diff or vimdiff and see what exactly cloc considered comments and blank lines. A rigorous proof that the stripped-down file contains the same C code as the original is to compile these files and compare checksums of the resulting object files.

First, the original source file:

prompt> gcc -c sqlite3.c
prompt> md5sum sqlite3.o
cce5f1a2ea27c7e44b2e1047e2588b49  sqlite3.o

Next, the version without comments:

prompt> mv sqlite3.c
prompt> gcc -c sqlite3.c
prompt> md5sum sqlite3.o
cce5f1a2ea27c7e44b2e1047e2588b49  sqlite3.o

cloc removed over 31,000 lines of comments and blanks but did not modify the source code in any significant way since the resulting object file matches the original.

Work with Compressed Archives ▲

Versions of cloc before v1.07 required an --extract-with=CMD option to tell cloc how to expand an archive file. Beginning with v1.07 this is extraction is attempted automatically. At the moment the automatic extraction method works reasonably well on Unix-type OS's for the following file types: .tar.gz, .tar.bz2, .tar.xz, .tgz, .zip, .ear, .deb. Some of these extensions work on Windows if one has WinZip installed in the default location (C:\Program Files\WinZip\WinZip32.exe). Additionally, with newer versions of WinZip, the is needed for correct operation; in this case one would invoke cloc with something like

 --extract-with="\"c:\Program Files\WinZip\wzunzip\" -e -o >FILE< ."
(ref. [](forum post)). In situations where the automatic extraction fails, one can try the `--extract-with=CMD` option to count lines of code within tar files, Zip files, or other compressed archives for which one has an extraction tool. cloc takes the user-provided extraction command and expands the archive to a temporary directory (created with File::Temp), counts the lines of code in the temporary directory, then removes that directory. While not especially helpful when dealing with a single compressed archive (after all, if you're going to type the extraction command anyway why not just manually expand the archive?) this option is handy for working with several archives at once. For example, say you have the following source tarballs on a Unix machine
perl-5.8.5.tar.gz Python-2.4.2.tar.gz and you want to count all the code within them. The command would be
cloc --extract-with='gzip -dc >FILE< | tar xf -' perl-5.8.5.tar.gz Python-2.4.2.tar.gz

If that Unix machine has GNU tar (which can uncompress and extract in one step) the command can be shortened to

cloc --extract-with='tar zxf >FILE<' perl-5.8.5.tar.gz Python-2.4.2.tar.gz

On a Windows computer with WinZip installed in c:\Program Files\WinZip the command would look like

cloc.exe --extract-with="\"c:\Program Files\WinZip\WinZip32.exe\" -e -o >FILE< ." perl-5.8.5.tar.gz Python-2.4.2.tar.gz

Java .ear files are Zip files that contain additional Zip files. cloc can handle nested compressed archives without difficulty--provided all such files are compressed and archived in the same way. Examples of counting a Java .ear file in Unix and Windows:

Unix> cloc --extract-with="unzip -d . >FILE< " Project.ear
DOS> cloc.exe --extract-with="\"c:\Program Files\WinZip\WinZip32.exe\" -e -o >FILE< ." Project.ear


The --diff switch allows one to measure the relative change in source code and comments between two versions of a file, directory, or archive. Differences reveal much more than absolute code counts of two file versions. For example, say a source file has 100 lines and its developer delivers a newer version with 102 lines. Did the developer add two comment lines, or delete seventeen source lines and add fourteen source lines and five comment lines, or did the developer do a complete rewrite, discarding all 100 original lines and adding 102 lines of all new source? The diff option tells how many lines of source were added, removed, modified or stayed the same, and how many lines of comments were added, removed, modified or stayed the same.

In addition to file pairs, one can give cloc pairs of directories, or pairs of file archives, or a file archive and a directory. cloc will try to align file pairs within the directories or archives and compare diffs for each pair. For example, to see what changed between GCC 4.4.0 and 4.5.0 one could do

cloc --diff gcc-4.4.0.tar.bz2  gcc-4.5.0.tar.bz2

Be prepared to wait a while for the results though; the --diff option runs much more slowly than an absolute code count.

To see how cloc aligns files between the two archives, use the --diff-alignment option

cloc --diff-aligment=align.txt gcc-4.4.0.tar.bz2  gcc-4.5.0.tar.bz2

to produce the file align.txt which shows the file pairs as well as files added and deleted. The symbols == and != before each file pair indicate if the files are identical (==) or if they have different content (!=).

Here's sample output showing the difference between the Python 2.6.6 and 2.7 releases:

prompt> cloc --diff Python-2.7.9.tgz Python-2.7.10.tar.xz
    4315 text files.
    4313 text files.s
    2173 files ignored.

4 errors:
Diff error, exceeded timeout:  /tmp/8ToGAnB9Y1/Python-2.7.9/Mac/Modules/qt/_Qtmodule.c
Diff error, exceeded timeout:  /tmp/M6ldvsGaoq/Python-2.7.10/Mac/Modules/qt/_Qtmodule.c
Diff error (quoted comments?):  /tmp/8ToGAnB9Y1/Python-2.7.9/Mac/Modules/qd/
Diff error (quoted comments?):  /tmp/M6ldvsGaoq/Python-2.7.10/Mac/Modules/qd/ v 1.65  T=298.59 s (0.0 files/s, 0.0 lines/s)
Language                   files          blank        comment           code
Visual Basic
 same                          2              0              1             12
 modified                      0              0              0              0
 added                         0              0              0              0
 removed                       0              0              0              0
 same                         11              0            340           2952
 modified                      1              0              0              1
 added                         0              0              0              0
 removed                       0              0              0              0
 same                          1              0             87            105
 modified                      0              0              0              0
 added                         0              0              0              0
 removed                       0              0              0              0
 same                          0              0             19            327
 modified                      1              0              0              1
 added                         0              0              0              0
 removed                       0              0              0              0
Objective C
 same                          7              0             61            635
 modified                      0              0              0              0
 added                         0              0              0              0
 removed                       0              0              0              0
NAnt script
 same                          2              0              0             30
 modified                      0              0              0              0
 added                         0              0              0              0
 removed                       0              0              0              0
 same                          3              0              2             72
 modified                      1              0              0              1
 added                         0              0              0              1
 removed                       0              1              0              0
Windows Resource File
 same                          3              0             56            206
 modified                      1              0              0              1
 added                         0              0              0              0
 removed                       0              0              0              0
 same                          6              0            161            565
 modified                      0              0              0              0
 added                         0              0              0              0
 removed                       0              0              0              0
 same                         14              0             11           2344
 modified                      0              0              0              0
 added                         0              0              0              0
 removed                       0              0              0              0
vim script
 same                          1              0              7            106
 modified                      0              0              0              0
 added                         0              0              0              0
 removed                       0              0              0              0
 same                          2              0             18            128
 modified                      0              0              0              0
 added                         0              0              0              0
 removed                       0              0              0              0
Windows Module Definition
 same                          7              0            187           2080
 modified                      2              0              0              0
 added                         0              0              0              1
 removed                       0              1              0              2
 same                          1              0              0             24
 modified                      0              0              0              0
 added                         0              0              0              0
 removed                       0              0              0              0
 same                          3              0             49            229
 modified                      0              0              0              0
 added                         0              0              0              0
 removed                       0              0              0              0
 same                         51              0           6794          12298
 modified                      0              0              0              0
 added                         0              0              0              0
 removed                       0              0              0              0
Bourne Shell
 same                         41              0           7698          45024
 modified                      1              0              0              3
 added                         0             13              2             64
 removed                       0              0              0              0
DOS Batch
 same                         29              0            107            494
 modified                      1              0              0              9
 added                         0              1              0              3
 removed                       0              0              0              0
MSBuild script
 same                         77              0              3          38910
 modified                      0              0              0              0
 added                         0              0              0              0
 removed                       0              0              0              0
 same                       1947              0         109012         430335
 modified                    192              0             94            950
 added                         2            323            283           2532
 removed                       2             55             58            646
 same                         18              0            191          15352
 modified                      1              0              0              2
 added                         1             31              0            205
 removed                       0              0              0              0
 same                        505              0          37439         347837
 modified                     45              0             13            218
 added                         0             90             33            795
 removed                       0              9              2            148
C/C++ Header
 same                        255              0          10361          66635
 modified                      5              0              5              7
 added                         0              1              3            300
 removed                       0              0              0              0
 same                       2986              0         172604         966700
 modified                    251              0            112           1193
 added                         3            459            321           3901
 removed                       2             66             60            796

A pair of errors occurred. The first pair was caused by timing out when computing diffs of the file Python-X/Mac/Modules/qt/_Qtmodule.c in each Python version. This file has > 26,000 lines of C code and takes more than 10 seconds--the default maximum duration for diff'ing a single file--on my slow computer. (Note: this refers to performing differences with the sdiff() function in the Perl Algorithm::Diff module, not the command line diff utility.) This error can be overcome by raising the time to, say, 20 seconds with --diff-timeout 20.

The second error is more problematic. The files Python-X/Mac/Modules/qd/ include Python docstring (text between pairs of triple quotes) containing C comments. cloc treats docstrings as comments and handles them by first converting them to C comments, then using the C comment removing regular expression. Nested C comments yield erroneous results however.

Create Custom Language Definitions ▲

cloc can write its language comment definitions to a file or can read comment definitions from a file, overriding the built-in definitions. This can be useful when you want to use cloc to count lines of a language not yet included, to change association of file extensions to languages, or to modify the way existing languages are counted.

The easiest way to create a custom language definition file is to make cloc write its definitions to a file, then modify that file:

Unix> cloc --write-lang-def=my_definitions.txt

creates the file my_definitions.txt which can be modified then read back in with either the --read-lang-def or --force-lang-def option. The difference between the options is former merges language definitions from the given file in with cloc's internal definitions with cloc's taking precedence if there are overlaps. The --force-lang-def option, on the other hand, replaces cloc's definitions completely. This option has a disadvantage in preventing cloc from counting languages whose extensions map to multiple languages as these languages require additional logic that is not easily expressed in a definitions file.

Unix> cloc --read-lang-def=my_definitions.txt  file1 file2 dir1 ...

Each language entry has four parts:

  • The language name starting in column 1.
  • One or more comment filters starting in column 5.
  • One or more filename extensions starting in column 5.
  • A 3rd generation scale factor starting in column 5. This entry must be provided but its value is not important unless you want to compare your language to a hypothetical third generation programming language.

A filter defines a method to remove comment text from the source file. For example the entry for C++ looks like this

    filter call_regexp_common C++
    filter remove_inline //.*$
    extension C
    extension c++
    extension cc
    extension cpp
    extension cxx
    extension pcc
    3rd_gen_scale 1.51
    end_of_line_continuation \\$

C++ has two filters: first, remove lines matching Regexp::Common's C++ comment regex. The second filter using remove_inline is currently unused. Its intent is to identify lines with both code and comments and it may be implemented in the future.

A more complete discussion of the different filter options may appear here in the future. The output of cloc's --write-lang-def option should provide enough examples for motivated individuals to modify or extend cloc's language definitions.

Combine Reports ▲

If you manage multiple software projects you might be interested in seeing line counts by project, not just by language. Say you manage three software projects called MariaDB, PostgreSQL, and SQLite. The teams responsible for each of these projects run cloc on their source code and provide you with the output. For example MariaDB team does

cloc --out mariadb-10.1.txt

and provides you with the file mariadb-10.1.txt. The contents of the three files you get are

Unix> cat mariadb-10.1.txt v 1.65  T=45.36 s (110.5 files/s, 66411.4 lines/s)
Language                         files          blank        comment           code
C++                               1613         225338         290077         983026
C                                  853          62442          73017         715018
C/C++ Header                      1327          48300         114577         209394
Bourne Shell                       256          10224          10810          61943
Perl                               147          10342           8305          35562
Pascal                             107           4907           5237          32541
HTML                                56            195              6          16489
Javascript                           5           3309           3019          15540
m4                                  30           1599            359          14215
CMake                              190           1919           4097          12206
XML                                 35            648             56           5210
Ruby                                59            619            184           4998
Puppet                              10              0              1           3848
make                               134            724            360           3631
SQL                                 23            306            377           3405
Python                              34            371            122           2545
Bourne Again Shell                  27            299            380           1604
Windows Module Definition           37             27             13           1211
lex                                  4            394            166            991
yacc                                 2            152             64            810
DOS Batch                           19             89             82            700
Prolog                               1              9             40            448
RobotFramework                       1              0              0            441
CSS                                  2             33            155            393
JSON                                 5              0              0            359
dtrace                               9             59            179            306
Windows Resource File               10             61             89            250
Assembly                             2             70            284            237
WiX source                           1             18             10            155
Visual Basic                         6              0              0             88
YAML                                 2              4              4             65
PHP                                  1             11              2             24
SKILL                                1              8             15             16
sed                                  2              0              0             16
Windows Message File                 1              2              8              6
diff                                 1              1              4              4
D                                    1              4             11              4
SUM:                              5014         372484         512110        2127699

Unix> cat sqlite-3081101.txt v 1.65  T=1.22 s (3.3 files/s, 143783.6 lines/s)
Language                     files          blank        comment           code
C                                2          11059          53924         101454
C/C++ Header                     2            211           6630           1546
SUM:                             4          11270          60554         103000

Unix> cat postgresql-9.4.4.txt v 1.65  T=22.46 s (172.0 files/s, 96721.6 lines/s)
Language                         files          blank        comment           code
HTML                              1254           3725              0         785991
C                                 1139         139289         244045         736519
C/C++ Header                       667          12277          32488          57014
SQL                                410          13400           8745          51926
yacc                                 8           3163           2669          28491
Bourne Shell                        41           2647           2440          17170
Perl                                81           1702           1308           9456
lex                                  9            792           1631           4285
make                               205           1525           1554           4114
m4                                  12            218             25           1642
Windows Module Definition           13              4             17           1152
XSLT                                 5             76             55            294
DOS Batch                            7             29             30             92
CSS                                  1             20              7             69
Assembly                             3             17             38             69
D                                    1             14             14             66
Windows Resource File                3              4              0             62
Lisp                                 1              1              1             16
sed                                  1              1              7             15
Python                               1              5              0             13
Bourne Again Shell                   1              8              6             10
Windows Message File                 1              0              0              5
SUM:                              3864         178917         295080        1698471

While these three files are interesting, you also want to see the combined counts from all projects. That can be done with cloc's --sum_reports option:

Unix> cloc --sum-reports --out=databases mariadb-10.1.txt  sqlite-3081101.txt  postgresql-9.4.4.txt
Wrote databases.lang
Wrote databases.file

The report combination produces two output files, one for sums by programming language (databases.lang) and one by project (databases.file). Their contents are

Unix> cat databases.lang v 1.65
Language                      files          blank        comment           code
C                              1994         212790         370986        1552991
C++                            1613         225338         290077         983026
HTML                           1310           3920              6         802480
C/C++ Header                   1996          60788         153695         267954
Bourne Shell                    297          12871          13250          79113
SQL                             433          13706           9122          55331
Perl                            228          12044           9613          45018
Pascal                          107           4907           5237          32541
yacc                             10           3315           2733          29301
m4                               42           1817            384          15857
Javascript                        5           3309           3019          15540
CMake                           190           1919           4097          12206
make                            339           2249           1914           7745
lex                              13           1186           1797           5276
XML                              35            648             56           5210
Ruby                             59            619            184           4998
Puppet                           10              0              1           3848
Python                           35            376            122           2558
Windows Module Definition        50             31             30           2363
Bourne Again Shell               28            307            386           1614
DOS Batch                        26            118            112            792
CSS                               3             53            162            462
Prolog                            1              9             40            448
RobotFramework                    1              0              0            441
JSON                              5              0              0            359
Windows Resource File            13             65             89            312
Assembly                          5             87            322            306
dtrace                            9             59            179            306
XSLT                              5             76             55            294
WiX source                        1             18             10            155
Visual Basic                      6              0              0             88
D                                 2             18             25             70
YAML                              2              4              4             65
sed                               3              1              7             31
PHP                               1             11              2             24
SKILL                             1              8             15             16
Lisp                              1              1              1             16
Windows Message File              2              2              8             11
diff                              1              1              4              4
SUM:                           8882         562671         867744        3929170

Unix> cat databases.file
File                            files          blank        comment           code
mariadb-10.1.txt                 5014         372484         512110        2127699
postgresql-9.4.4.txt             3864         178917         295080        1698471
sqlite-3081101.txt                  4          11270          60554         103000
SUM:                             8882         562671         867744        3929170

Report files themselves can be summed together. Say you also manage development of Perl and Python and you want to keep track of those line counts separately from your database projects. First create reports for Perl and Python separately:

cloc --out perl-5.22.0.txt   perl-5.22.0.tar.gz
cloc --out python-2.7.10.txt Python-2.7.10.tar.xz

then sum these together with

Unix> cloc --sum-reports --out script_lang perl-5.22.0.txt python-2.7.10.txt
Wrote script_lang.lang
Wrote script_lang.file

Unix> cat script_lang.lang v 1.65
Language                     files          blank        comment           code
Perl                          2892         136396         184362         536445
C                              680          75566          71211         531203
Python                        2141          89642         109524         434015
C/C++ Header                   408          16433          26938         214800
Bourne Shell                   154          11088          14496          87759
MSBuild script                  77              0              3          38910
m4                              20           1604            191          15559
Assembly                        51           3775           6794          12298
Pascal                           8            458           1603           8592
make                            16            897            828           4939
XML                             37            198              2           2484
HTML                            14            393             11           2344
C++                             12            338            295           2161
Windows Module Definition        9            171            187           2081
YAML                            49             20             15           2078
Prolog                          12            438              2           1146
JSON                            14              1              0           1037
yacc                             1             85             76            998
DOS Batch                       44            199            148            895
Objective C                      7             98             61            635
Expect                           6            104            161            565
Windows Message File             1            102             11            489
CSS                              1             98             19            328
Windows Resource File            7             55             56            292
Javascript                       3             31             49            229
vim script                       1             36              7            106
diff                             1             17             87            105
NAnt script                      2              1              0             30
IDL                              1              0              0             24
Visual Basic                     2              1              1             12
D                                1              5              7              8
Lisp                             2              0              3              4
SUM:                          6674         338250         417148        1902571

Unix> cat script_lang.file
File                         files          blank        comment           code
python-2.7.10.txt             3240         161276         173214         998697
perl-5.22.0.txt               3434         176974         243934         903874
SUM:                          6674         338250         417148        1902571

Finally, combine the combination files:

Unix> cloc --sum-reports --report_file=everything databases.lang script_lang.lang
Wrote everything.lang
Wrote everything.file

Unix> cat everything.lang v 1.65
Language                       files          blank        comment           code
C                               2674         288356         442197        2084194
C++                             1625         225676         290372         985187
HTML                            1324           4313             17         804824
Perl                            3120         148440         193975         581463
C/C++ Header                    2404          77221         180633         482754
Python                          2176          90018         109646         436573
Bourne Shell                     451          23959          27746         166872
SQL                              433          13706           9122          55331
Pascal                           115           5365           6840          41133
MSBuild script                    77              0              3          38910
m4                                62           3421            575          31416
yacc                              11           3400           2809          30299
Javascript                         8           3340           3068          15769
make                             355           3146           2742          12684
Assembly                          56           3862           7116          12604
CMake                            190           1919           4097          12206
XML                               72            846             58           7694
lex                               13           1186           1797           5276
Ruby                              59            619            184           4998
Windows Module Definition         59            202            217           4444
Puppet                            10              0              1           3848
YAML                              51             24             19           2143
DOS Batch                         70            317            260           1687
Bourne Again Shell                28            307            386           1614
Prolog                            13            447             42           1594
JSON                              19              1              0           1396
CSS                                4            151            181            790
Objective C                        7             98             61            635
Windows Resource File             20            120            145            604
Expect                             6            104            161            565
Windows Message File               3            104             19            500
RobotFramework                     1              0              0            441
dtrace                             9             59            179            306
XSLT                               5             76             55            294
WiX source                         1             18             10            155
diff                               2             18             91            109
vim script                         1             36              7            106
Visual Basic                       8              1              1            100
D                                  3             23             32             78
sed                                3              1              7             31
NAnt script                        2              1              0             30
IDL                                1              0              0             24
PHP                                1             11              2             24
Lisp                               3              1              4             20
SKILL                              1              8             15             16
SUM:                           15556         900921        1284892        5831741

Unix> cat everything.file
File                         files          blank        comment           code
databases.lang                8882         562671         867744        3929170
script_lang.lang              6674         338250         417148        1902571
SUM:                         15556         900921        1284892        5831741


Cloc can write results in the form of SQL table create and insert statements for use with relational database programs such as SQLite, MySQL, PostgreSQL, Oracle, or Microsoft SQL. Once the code count information is in a database, the information can be interrogated and displayed in interesting ways.

A database created from cloc SQL output has two tables, metadata and t:

Table metadata:

Field Type
timestamp text
project text
elapsed_s text

Table t:

Field Type
project text
language text
file text
nBlank integer
nComment integer
nCode integer
nScaled real

The metadata table contains information about when the cloc run was made. The --sql-append switch allows one to combine many runs in a single database; each run adds a row to the metadata table. The code count information resides in table t.

Let's repeat the code count examples of Perl, Python, SQLite, MySQL and PostgreSQL tarballs shown in the Combine Reports example above, this time using the SQL output options and the SQLite database engine.

The --sql switch tells cloc to generate output in the form of SQL table create and insert commands. The switch takes an argument of a file name to write these SQL statements into, or, if the argument is 1 (numeric one), streams output to STDOUT. Since the SQLite command line program, sqlite3, can read commands from STDIN, we can dispense with storing SQL statements to a file and use --sql 1 to pipe data directly into the SQLite executable:

cloc --sql 1 --sql-project mariadb | sqlite3 code.db

The --sql-project mariadb part is optional; there's no need to specify a project name when working with just one code base. However, since we'll be adding code counts from four other tarballs, we'll only be able to identify data by input source if we supply a project name for each run.

Now that we have a database we will need to pass in the --sql-append switch to tell cloc not to wipe out this database but instead add more data:

cloc --sql 1 --sql-project postgresql --sql-append postgresql-9.4.4.tar.bz2        | sqlite3 code.db
cloc --sql 1 --sql-project sqlite     --sql-append | sqlite3 code.db
cloc --sql 1 --sql-project python     --sql-append Python-2.7.10.tar.xz            | sqlite3 code.db
cloc --sql 1 --sql-project perl       --sql-append perl-5.22.0.tar.gz              | sqlite3 code.db

Now the fun begins--we have a database, code.db, with lots of information about the five projects and can query it for all manner of interesting facts.

Which is the longest file over all projects?

prompt> sqlite3 code.db 'select project,file,nBlank+nComment+nCode as nL from t
                                 where nL = (select max(nBlank+nComment+nCode) from t)'


sqlite3's default output format leaves a bit to be desired. We can add an option to the program's rc file, ~/.sqliterc, to show column headers:

  .header on

One might be tempted to also include

  .mode column

in ~/.sqliterc but this causes problems when the output has more than one row since the widths of entries in the first row govern the maximum width for all subsequent rows. Often this leads to truncated output--not at all desirable. One option is to write a custom SQLite output formatter such as sqlite_formatter, included with cloc.

To use it, simply pass sqlite3's STDOUT into sqlite_formatter via a pipe:

prompt> sqlite3 code.db 'select project,file,nBlank+nComment+nCode as nL from t
                         where nL = (select max(nBlank+nComment+nCode) from t)' | ./sqlite_formatter
  -- Loading resources from ~/.sqliterc
  Project File                                  nL
  _______ _____________________________________ ______
  sqlite  sqlite-amalgamation-3081101/sqlite3.c 161623

If the "Project File" line doesn't appear, add .header on to your ~/.sqliterc file as explained above.

What is the longest file over all projects?

prompt> sqlite3 code.db 'select project,file,nBlank+nComment+nCode as nL from t
                         where nL = (select max(nBlank+nComment+nCode) from t)' | sqlite_formatter

Project File                                  nL
_______ _____________________________________ ______
sqlite  sqlite-amalgamation-3081101/sqlite3.c 161623

What is the longest file in each project?

prompt> sqlite3 code.db 'select project,file,max(nBlank+nComment+nCode) as nL from t
                          group by project order by nL;' | sqlite_formatter

Project    File                                                             nL
__________ ________________________________________________________________ ______
python     Python-2.7.10/Mac/Modules/qt/_Qtmodule.c                          28091
postgresql postgresql-9.4.4/src/interfaces/ecpg/preproc/preproc.c            54623
mariadb    server-10.1/storage/mroonga/vendor/groonga/lib/nfkc.c             80246
perl       perl-5.22.0/cpan/Locale-Codes/lib/Locale/Codes/ 100747
sqlite     sqlite-amalgamation-3081101/sqlite3.c                            161623

Which files in each project have the most code lines?

prompt> sqlite3 code.db 'select project,file,max(nCode) as nL from t
                         group by project order by nL desc;' | sqlite_formatter

Project    File                                                             nL
__________ ________________________________________________________________ ______
perl       perl-5.22.0/cpan/Locale-Codes/lib/Locale/Codes/ 100735
sqlite     sqlite-amalgamation-3081101/sqlite3.c                             97469
mariadb    server-10.1/storage/mroonga/vendor/groonga/lib/nfkc.c             80221
postgresql postgresql-9.4.4/src/interfaces/ecpg/preproc/preproc.c            45297
python     Python-2.7.10/Mac/Modules/qt/_Qtmodule.c                          26705

Which C source files with more than 300 lines have a comment ratio below 1%?

prompt> sqlite3 code.db 'select project, file, nCode, nComment,
                         (100.0*nComment)/(nComment+nCode) as comment_ratio from t
                         where language="C" and nCode > 300 and
                         comment_ratio < 1 order by comment_ratio;' | sqlite_formatter

Project    File                                                                                            nCode nComment comment_ratio
__________ _______________________________________________________________________________________________ _____ ________ __________________
mariadb    server-10.1/storage/mroonga/vendor/groonga/lib/nfkc.c                                           80221       14 0.0174487443135789
python     Python-2.7.10/Python/graminit.c                                                                  2175        1 0.0459558823529412
postgresql postgresql-9.4.4/src/backend/snowball/libstemmer/stem_UTF_8_turkish.c                            2095        1 0.0477099236641221
postgresql postgresql-9.4.4/src/backend/snowball/libstemmer/stem_UTF_8_french.c                             1211        1 0.0825082508250825
postgresql postgresql-9.4.4/src/backend/snowball/libstemmer/stem_ISO_8859_1_french.c                        1201        1 0.0831946755407654
postgresql postgresql-9.4.4/src/backend/snowball/libstemmer/stem_UTF_8_hungarian.c                          1182        1 0.084530853761623
postgresql postgresql-9.4.4/src/backend/snowball/libstemmer/stem_ISO_8859_1_hungarian.c                     1178        1 0.0848176420695505
mariadb    server-10.1/strings/ctype-eucjpms.c                                                             67466       60 0.0888546633889169
postgresql postgresql-9.4.4/src/backend/snowball/libstemmer/stem_UTF_8_english.c                            1072        1 0.0931966449207828
postgresql postgresql-9.4.4/src/backend/snowball/libstemmer/stem_ISO_8859_1_english.c                       1064        1 0.0938967136150235
postgresql postgresql-9.4.4/src/backend/snowball/libstemmer/stem_UTF_8_spanish.c                            1053        1 0.094876660341556
postgresql postgresql-9.4.4/src/backend/snowball/libstemmer/stem_ISO_8859_1_spanish.c                       1049        1 0.0952380952380952
postgresql postgresql-9.4.4/src/backend/snowball/libstemmer/stem_UTF_8_italian.c                            1031        1 0.0968992248062016
postgresql postgresql-9.4.4/src/backend/snowball/libstemmer/stem_ISO_8859_1_italian.c                       1023        1 0.09765625
postgresql postgresql-9.4.4/src/backend/snowball/libstemmer/stem_UTF_8_portuguese.c                          981        1 0.10183299389002
postgresql postgresql-9.4.4/src/backend/snowball/libstemmer/stem_ISO_8859_1_portuguese.c                     975        1 0.102459016393443
postgresql postgresql-9.4.4/src/backend/snowball/libstemmer/stem_UTF_8_romanian.c                            967        1 0.103305785123967
postgresql postgresql-9.4.4/src/backend/snowball/libstemmer/stem_ISO_8859_2_romanian.c                       961        1 0.103950103950104
mariadb    server-10.1/strings/ctype-ujis.c                                                                67177       79 0.117461639110265
postgresql postgresql-9.4.4/src/backend/snowball/libstemmer/stem_UTF_8_finnish.c                             720        1 0.13869625520111
postgresql postgresql-9.4.4/src/backend/snowball/libstemmer/stem_UTF_8_porter.c                              717        1 0.139275766016713
postgresql postgresql-9.4.4/src/backend/snowball/libstemmer/stem_ISO_8859_1_finnish.c                        714        1 0.13986013986014
postgresql postgresql-9.4.4/src/backend/snowball/libstemmer/stem_ISO_8859_1_porter.c                         711        1 0.140449438202247
postgresql postgresql-9.4.4/src/backend/snowball/libstemmer/stem_KOI8_R_russian.c                            660        1 0.151285930408472
postgresql postgresql-9.4.4/src/backend/snowball/libstemmer/stem_UTF_8_russian.c                             654        1 0.152671755725191
python     Python-2.7.10/Mac/Modules/qt/_Qtmodule.c                                                        26705       42 0.157026956294164
python     Python-2.7.10/Mac/Modules/icn/_Icnmodule.c                                                       1521        3 0.196850393700787
mariadb    server-10.1/strings/ctype-extra.c                                                                8282       18 0.216867469879518
postgresql postgresql-9.4.4/src/bin/psql/sql_help.c                                                         3576        8 0.223214285714286
mariadb    server-10.1/strings/ctype-sjis.c                                                                34006       86 0.252258594391646
python     Python-2.7.10/Python/Python-ast.c                                                                6554       17 0.258712524729874
mariadb    server-10.1/strings/ctype-cp932.c                                                               34609       92 0.265122042592432
perl       perl-5.22.0/keywords.c                                                                           2815        8 0.283386468296139
python     Python-2.7.10/Mac/Modules/menu/_Menumodule.c                                                     3263       10 0.305530094714329
postgresql postgresql-9.4.4/src/backend/snowball/libstemmer/stem_UTF_8_dutch.c                               596        2 0.334448160535117
postgresql postgresql-9.4.4/src/backend/snowball/libstemmer/stem_ISO_8859_1_dutch.c                          586        2 0.340136054421769
mariadb    server-10.1/strings/ctype-gbk.c                                                                 10684       38 0.354411490393583
python     Python-2.7.10/Mac/Modules/qd/_Qdmodule.c                                                         6694       24 0.357249181303959
python     Python-2.7.10/Mac/Modules/win/_Winmodule.c                                                       3056       11 0.358656667753505
postgresql postgresql-9.4.4/src/backend/snowball/libstemmer/stem_UTF_8_german.c                              476        2 0.418410041841004
postgresql postgresql-9.4.4/src/backend/snowball/libstemmer/stem_ISO_8859_1_german.c                         470        2 0.423728813559322
mariadb    server-10.1/strings/ctype-euc_kr.c                                                               9956       44 0.44
postgresql postgresql-9.4.4/src/backend/utils/fmgrtab.c                                                     4815       23 0.475403059115337
python     Python-2.7.10/Mac/Modules/ctl/_Ctlmodule.c                                                       5442       28 0.511882998171846
python     Python-2.7.10/Mac/Modules/ae/_AEmodule.c                                                         1347        7 0.51698670605613
python     Python-2.7.10/Mac/Modules/app/_Appmodule.c                                                       1712        9 0.52295177222545
mariadb    server-10.1/strings/ctype-gb2312.c                                                               6377       35 0.54585152838428
mariadb    server-10.1/storage/tokudb/ft-index/third_party/xz-4.999.9beta/src/liblzma/lzma/fastpos_table.c   516        3 0.578034682080925
python     Python-2.7.10/Mac/Modules/evt/_Evtmodule.c                                                        504        3 0.591715976331361
python     Python-2.7.10/Modules/expat/xmlrole.c                                                            1256        8 0.632911392405063
postgresql postgresql-9.4.4/src/backend/snowball/libstemmer/stem_UTF_8_danish.c                              312        2 0.636942675159236
postgresql postgresql-9.4.4/src/backend/snowball/libstemmer/stem_ISO_8859_1_danish.c                         310        2 0.641025641025641
python     Python-2.7.10/Mac/Modules/res/_Resmodule.c                                                       1621       12 0.734843845682792
python     Python-2.7.10/Mac/Modules/drag/_Dragmodule.c                                                     1046        8 0.759013282732448
python     Python-2.7.10/Mac/Modules/list/_Listmodule.c                                                     1021        8 0.777453838678329
python     Python-2.7.10/Mac/Modules/te/_TEmodule.c                                                         1198       10 0.827814569536424
python     Python-2.7.10/Mac/Modules/cg/_CGmodule.c                                                         1190       10 0.833333333333333
python     Python-2.7.10/Modules/clmodule.c                                                                 2379       23 0.957535387177352
python     Python-2.7.10/Mac/Modules/folder/_Foldermodule.c                                                  306        3 0.970873786407767

What are the ten longest files (based on code lines) that have no comments at all? Exclude header, .html, and YAML files.

prompt> sqlite3 code.db 'select project, file, nCode from t
                         where nComment = 0 and
                         language not in ("C/C++ Header", "YAML", "HTML")
                         order by nCode desc limit 10;' | sqlite_formatter

Project File                                                                 nCode
_______ ____________________________________________________________________ _____
perl    perl-5.22.0/cpan/Unicode-Collate/Collate/Locale/                 1938
python  Python-2.7.10/PCbuild/pythoncore.vcproj                               1889
python  Python-2.7.10/PC/VS8.0/pythoncore.vcproj                              1889
mariadb server-10.1/mysql-test/extra/binlog_tests/  1862
perl    perl-5.22.0/cpan/Unicode-Collate/Collate/Locale/            1589
perl    perl-5.22.0/cpan/Unicode-Collate/Collate/Locale/             1563
mariadb server-10.1/storage/mroonga/vendor/groonga/               1526
perl    perl-5.22.0/cpan/Unicode-Collate/Collate/Locale/             1505
mariadb server-10.1/mysql-test/suite/funcs_1/storedproc/     1465
python  Python-2.7.10/PC/VS8.0/_bsddb.vcproj                                  1463

What are the most popular languages (in terms of lines of code) in each project?

prompt> sqlite3 code.db 'select project, language, sum(nCode) as SumCode from t
                         group by project,language
                         order by project,SumCode desc;' | sqlite_formatter
Project    Language                  SumCode
__________ _________________________ _______
mariadb    C++                        983026
mariadb    C                          715018
mariadb    C/C++ Header               209394
mariadb    Bourne Shell                61943
mariadb    Perl                        35562
mariadb    Pascal                      32541
mariadb    HTML                        16489
mariadb    Javascript                  15540
mariadb    m4                          14215
mariadb    CMake                       12206
mariadb    XML                          5210
mariadb    Ruby                         4998
mariadb    Puppet                       3848
mariadb    make                         3631
mariadb    SQL                          3405
mariadb    Python                       2545
mariadb    Bourne Again Shell           1604
mariadb    Windows Module Definition    1211
mariadb    lex                           991
mariadb    yacc                          810
mariadb    DOS Batch                     700
mariadb    Prolog                        448
mariadb    RobotFramework                441
mariadb    CSS                           393
mariadb    JSON                          359
mariadb    dtrace                        306
mariadb    Windows Resource File         250
mariadb    Assembly                      237
mariadb    WiX source                    155
mariadb    Visual Basic                   88
mariadb    YAML                           65
mariadb    PHP                            24
mariadb    SKILL                          16
mariadb    sed                            16
mariadb    Windows Message File            6
mariadb    D                               4
mariadb    diff                            4
perl       Perl                       536445
perl       C                          155648
perl       C/C++ Header               147858
perl       Bourne Shell                42668
perl       Pascal                       8592
perl       XML                          2410
perl       YAML                         2078
perl       C++                          2033
perl       make                         1986
perl       Prolog                       1146
perl       JSON                         1037
perl       yacc                          998
perl       Windows Message File          489
perl       DOS Batch                     389
perl       Windows Resource File          85
perl       D                               8
perl       Lisp                            4
postgresql HTML                       785991
postgresql C                          736519
postgresql C/C++ Header                57014
postgresql SQL                         51926
postgresql yacc                        28491
postgresql Bourne Shell                17170
postgresql Perl                         9456
postgresql lex                          4285
postgresql make                         4114
postgresql m4                           1642
postgresql Windows Module Definition    1152
postgresql XSLT                          294
postgresql DOS Batch                      92
postgresql Assembly                       69
postgresql CSS                            69
postgresql D                              66
postgresql Windows Resource File          62
postgresql Lisp                           16
postgresql sed                            15
postgresql Python                         13
postgresql Bourne Again Shell             10
postgresql Windows Message File            5
python     Python                     434015
python     C                          375555
python     C/C++ Header                66942
python     Bourne Shell                45091
python     MSBuild script              38910
python     m4                          15559
python     Assembly                    12298
python     make                         2953
python     HTML                         2344
python     Windows Module Definition    2081
python     Objective C                   635
python     Expect                        565
python     DOS Batch                     506
python     CSS                           328
python     Javascript                    229
python     Windows Resource File         207
python     C++                           128
python     vim script                    106
python     diff                          105
python     XML                            74
python     NAnt script                    30
python     Prolog                         24
python     Visual Basic                   12
sqlite     C                          101454
sqlite     C/C++ Header                 1546

Third Generation Language Scale Factors ▲

cloc versions before 1.50 by default computed, for the provided inputs, a rough estimate of how many lines of code would be needed to write the same code in a hypothetical third-generation computer language. To produce this output one must now use the --3 switch.

Scale factors were derived from the 2006 version of language gearing ratios listed at Mayes Consulting web site,, using this equation:

cloc scale factor for language X = 3rd generation default gearing ratio / language X gearing ratio

For example, cloc 3rd generation scale factor for DOS Batch = 80 / 128 = 0.625.

The biggest flaw with this approach is that gearing ratios are defined for logical lines of source code not physical lines (which cloc counts). The values in cloc's 'scale' and '3rd gen. equiv.' columns should be taken with a large grain of salt.

Limitations ▲

Identifying comments within source code is trickier than one might expect. Many languages would need a complete parser to be counted correctly. cloc does not attempt to parse any of the languages it aims to count and therefore is an imperfect tool. The following are known problems:

  1. Lines containing both source code and comments are counted as lines of code.
  2. Comment markers within strings or here-documents are treated as actual comment markers and not string literals. For example the following lines of C code
    printf(" /* ");
    for (i = 0; i < 100; i++) {
        a += i;
    printf(" */ ");
    look to cloc like this:
    printf(" xxxxxxx
    xxxxxxx     ");
    where `xxxxxxx` represents cloc's view of commented text. Therefore cloc counts the five lines as two lines of C code and three lines of comments (lines with both code and comment are counted as code).

How to Request Support for Additional Languages ▲

If cloc does not recognize a language you are interested in counting, create a GitHub issue requesting support for your language. Include this information:

  1. File extensions associated with the language. If the language does not rely on file extensions and instead works with fixed file names or with `#!` style program invocations, explain what those are.
  2. A description of how comments are defined.
  3. Links to sample code.

Features Currently in Development ▲

Here, in no particular order and with no promise of future delivery, are features and capabilities currently in development:

  1. produce reStructuredText output with `--rst`
  2. count code (e.g. Javascript) embedded in HTML files

Pull requests for these features will receive extra consideration.

Acknowledgments ▲

Wolfram Rösler provided most of the code examples in the test suite. These examples come from his Hello World collection.

Ismet Kursunoglu found errors with the MUMPS counter and provided access to a computer with a large body of MUMPS code to test cloc.

Tod Huggins gave helpful suggestions for the Visual Basic filters.

Anton Demichev found a flaw with the JSP counter in cloc v0.76 and wrote the XML output generator for the --xml option.

Reuben Thomas pointed out that ISO C99 allows // as a comment marker, provided code for the --no3 and --stdin-name options, counting the m4 language, and suggested several user-interface enhancements.

Michael Bello provided code for the --opt-match-f, --opt-not-match-f, --opt-match-d, and --opt-not-match-d options.

Mahboob Hussain inspired the --original-dir and --skip-uniqueness options, found a bug in the duplicate file detection logic and improved the JSP filter.

Randy Sharo found and fixed an uninitialized variable bug for shell scripts having only one line.

Steven Baker found and fixed a problem with the YAML output generator.

Greg Toth provided code to improve blank line detection in COBOL.

Joel Oliveira provided code to let --exclude-list-file handle directory name exclusion.

Blazej Kroll provided code to produce an XSLT file, cloc-diff.xsl, when producing XML output for the --diff option.

Denis Silakov enhanced the code which generates cloc.xsl when using --by-file and --by-file-by-lang options, and provided an XSL file that works with --diff output.

Andy ( provided code to fix several bugs: correct output of --counted so that only files that are used in the code count appear and that results are shown by language rather than file name; allow --diff output from multiple runs to be summed together with --sum-reports.

Jari Aalto created the initial version of cloc.1.pod and maintains the Debian package for cloc.

Mikkel Christiansen ( provided counter definitions for Clojure and ClojureScript.

Vera Djuraskovic from provided the Serbo-Croatian translation.

Gill Ajoft of Ajoft Softwares provided the Bulgarian translation.

The Knowledge Team provided the Slovakian translation.

Erik Gooven Arellano Casillas provided an update to the MXML counter to recognize Actionscript comments.

Gianluca Casati created the cloc CPAN package.

Mary Stefanova provided the Polish translation.

Ryan Lindeman implemented the --by-percent feature.

Kent C. Dodds, @kentcdodds, created and maintains the npm package of cloc.

Anna Litwinka provided the Russian translation.

Science Blog provided the Russian translation.

Viktoria Parnak provided the Ukrainian translation.

Natalie Harmann provided the Belarussian translation.

Nithyal at Healthcare Administration Portal provided the Tamil translation.

Patricia Motosan provided the Romanian translation.

The Garcinia Cambogia Review Team provided the Arabic translation.

Gajk Melikyan provided the provided the Armenian translation for

The development of cloc was partially funded by the Northrop Grumman Corporation.

Copyright ▲

Copyright (c) 2006-2016, Al Danial