diff.txt

vimdiff            (1)  - edit two or three versions of a file with Vim and sh
diff3              (1)  - find differences between three files

diff               (1)  - find differences between two files
lsdiff             (1)  - show which files are modified by a patch
diffstat           (1)  - make histogram from diff-output

bzdiff             (1)  - compare bzip2 compressed files
zdiff              (1)  - compare compressed files


Example 1: net-snmp has old files and net-snmp-new has newly changed files
-------------------------------------------------------------------------
1. from directory one level above net-snmp:

   $ diff -b -B --unified=3 net-snmp/configure net-snmp-new/configure > configureDiff.txt

   -b: ignore changes in white space
   -B: ignore blank lines insertion/deletion
   --unified=3: unified output file format with 3 lines of context

2. in the net-snmp directory:

   $ patch -p1 < configureDiff.txt

   -p1: remove one directory level e.g:
   "net-snmp/configure" is converted to "configrue"



Example 2: files in src/new used to update files in proj/src/old
-----------------------------------------------------------------
1. create the pathfile
   diff -burN proj/src/old  src/new > patchfile
   The order is important the patch will be applied to the first file
   

2. Apply the patch
   patch -p0 < patchfile

   patch will be applied to first file listed in the patchfile, which in 
   this case will be 'src/old'
   -p0 is needed to preserve the path, otherwise 'proj/src/old' will 
   become 'old'.
   use -p1 if running patch from proj directory to tell patch to patch
   src/old
   



Applying patch to some of the files in a directory
---------------------------------------------------
1. Creating patch:
   cd repro
   cat ~/workspace/changedFiles.txt | xargs -i diff -b -B --unified=3 {} \
   ~/5300_box/snapgear/lib/resiprocate/repro{} >> resip-1.1.patch


2. Applying patch:
   patch < resip-1.1.patch


Patching a files in current dir with files from another dir
-----------------------------------------------------------
cat changedFilesList.txt | xargs -i diff -burN {} ~/tmp/{} | patch


What files differ in 2 directories
----------------------------------
1. create a file with exclude patterns with one pattern on each line
   for example:
   *.o
   *~
   *kdevelop*
   *kdevses*

2. diff --brief --exclude-from=excludepattern . ~/5300/e30/mand/ | egrep '^Files.*' \
 | sed 's/and//


Selecting only c h and cpp files
--------------------------------

find ~/project/5300_78/e30/mand -maxdepth 1 -regex '.*\.[ch]\(pp\)?' | xargs
-i basename {} | xargs -i diff -buN mand/{} ~/project/5300_78/e30/mand/{} >
patchfile2.txt




patch files that match a pattern
--------------------------------
find . -regex './b2bua.*[hp]$' | xargs -i diff -u {} $DIFF_TARGET/ > patchfile.txt