brep

#!/usr/bin/env bash
#
# NAME
#
#   brep - better grep
#
# SYNOPSIS
#
#   brep <pattern> [<path>...] [<option>...]
#
# DESCRIPTION
#
#   Every once in a while someone writes an alternative to grep(1)
#   (e.g., ack, ag, pt, rg, etc.) and I have to struggle to relearn
#   things, change 'grepprg' in Vim, etc.  brep is a once-and-for-all
#   alternative to all these programs.  brep is a GNU grep(1) wrapper in
#   about 70 lines of Bash.  Of course, brep is only as fast as grep(1)
#   is.  Thus, if efficiency is a very critical requirement, then you
#   should not use brep.  brep is inspired by a strong preference for
#   conservatism over innovation in software.
#
# USAGE/OPTIONS
#
#   The first argument in the argument list must be a valid Perl regular
#   expression and the rest of the args can be directories/files or
#   grep(1) options.  The order of pattern -> path -> option in the
#   argument list must be maintained for brep to work.  All valid
#   grep(1) options (except the matcher selection options, -EFGP) can be
#   given to brep.  Additionally, we define the following
#   aliases/options:
#
#       -if <glob>, --include=<glob>
#           include files matching glob
#
#       -ef <glob>, --exclude=<glob>
#           exclude files matching glob
#
#       -ed <glob>, --exclude-dir=<glob>
#           exclude directories matching glob
#
#       -ns, --no-smart
#           disable smartness (i.e., do not any ignore files
#           by default, no smart regex, etc.)
#
# DEPENDENCIES
#
#   GNU's variant of grep(1)
#

[[ "$*" ]] || {
    echo >&2 "usage: ${0##*/} <pattern> [<file>...] [<options>...]"
    exit 1
}

patt="$1"; shift
while [[ "$1" ]]
do
    # The first argument starting with a `-' is assumed to
    # begin the option chain.
    [[ "$1" =~ ^-.* ]] && break

    # If the argument is a regular file/directory, assume that the user
    # wants to grep the file/directory.  Otherwise assume that it's
    # a glob to restrict matches.
    [[ -e "$1" ]] && files+=( "$1" ) || args+=( --include="$1" )

    shift
done

smart="yes"
while [[ "$1" ]]
do
    # Now that we're done with files, process aliases.
    case "$1" in
        -ed) args+=( "--exclude-dir=${2}" ); shift 2 ;;
        -ef) args+=( "--exclude=${2}" ); shift 2     ;;
        -if) args+=( "--include=${2}" ); shift 2     ;;
        -ns|--no-smart)
             smart="no"; shift                       ;;
        *)   args+=( "$1" ); shift                   ;;
    esac
done

# Default grep options.
args+=(
    --binary-files=without-match
    --dereference-recursive
    --devices=skip
    --perl-regexp
)

# Only add line numbers and colors if the stdout is attached
# to a terminal.
[[ -t 1 ]] && args+=(--color=auto --line-number)

[[ "$smart" == "yes" ]] && {
    # Smart regex: if the pattern contains at least one upper-case
    # letter, assume that the user wants a case-sensitive search.
    [[ "$patt" =~ [A-Z] ]] || args+=( --ignore-case )

    # Ignore some common VCS directories, backup files, etc.
    # Curated from the ack source: https://beyondgrep.com/
    args+=(
        ### Directories to ignore ###

        # Bazaar
        # http://bazaar.canonical.com/
        --exclude-dir=.bzr

        # Codeville
        # http://freecode.com/projects/codeville
        --exclude-dir=.cdv

        # Interface Builder (Xcode)
        # http://en.wikipedia.org/wiki/Interface_Builder
        --exclude-dir=~.dep
        --exclude-dir=~.dot
        --exclude-dir=~.nib
        --exclude-dir=~.plst

        # Git
        # http://git-scm.com/
        --exclude-dir=.git

        # Mercurial
        # http://mercurial.selenic.com/
        --exclude-dir=.hg

        # quilt
        # http://directory.fsf.org/wiki/Quilt
        --exclude-dir=.pc

        # Subversion
        # http://subversion.tigris.org/
        --exclude-dir=.svn

        # Monotone
        # http://www.monotone.ca/
        --exclude-dir=_MTN

        # CVS
        # http://savannah.nongnu.org/projects/cvs
        --exclude-dir=CVS

        # RCS
        # http://www.gnu.org/software/rcs/
        --exclude-dir=RCS

        # SCCS
        # http://en.wikipedia.org/wiki/Source_Code_Control_System
        --exclude-dir=SCCS

        # darcs
        # http://darcs.net/
        --exclude-dir=_darcs

        # Vault/Fortress
        --exclude-dir=_sgbak

        # autoconf
        # http://www.gnu.org/software/autoconf/
        --exclude-dir=autom4te.cache

        # Perl module building
        --exclude-dir=blib
        --exclude-dir=_build

        # Perl Devel::Cover module's output directory
        # https://metacpan.org/release/Devel-Cover
        --exclude-dir=cover_db

        # Node modules created by npm
        --exclude-dir=node_modules

        # CMake cache
        # http://www.cmake.org/
        --exclude-dir=CMakeFiles

        # Eclipse workspace folder
        # http://eclipse.org/
        --exclude-dir=.metadata

        # Cabal (Haskell) sandboxes
        # http://www.haskell.org/cabal/users-guide/installing-packages.html
        --exclude-dir=.cabal-sandbox

        # Python caches
        # https://docs.python.org/3/tutorial/modules.html
        --exclude-dir=__pycache__
        --exclude-dir=.pytest_cache

        # Filesystem crap
        --exclude-dir=__MACOSX
        --exclude-dir=.Spotlight-V100
        --exclude-dir=.Trash
        --exclude-dir=.Trash-1000

        ### Files to ignore ###

        # Backup files
        --exclude=*.bak
        --exclude=*~

        # Emacs swap files
        --exclude=\#*\#

        # vi/vim swap files http://vim.org/
        --exclude=[._]*.swp
	--exclude=viminfo

        # Minified CSS/Javascript
        --exclude=*[-.]min.css
        --exclude=*[-.]min.js
    )
}

exec grep "${args[@]}" -- "$patt" "${files[@]}"