Lightning-fast project-wide find/replace with git grep and sed

.profile fragment

  gg_replace() {
    if [[ "$#" == "0" ]]; then
      echo 'Usage:'
      echo '  gg_replace term replacement file_mask'
      echo
      echo 'Example:'
      echo '  gg_replace cappuchino cappuccino *.html'
      echo
    else
      find=$1; shift
      replace=$1; shift

      ORIG_GLOBIGNORE=$GLOBIGNORE
      GLOBIGNORE=*.*
      
      if [[ "$#" = "0" ]]; then
        set -- ' ' $@
      fi

      while [[ "$#" -gt "0" ]]; do
        for file in `git grep -l $find -- $1`; do
          sed -e "s/$find/$replace/g" -i'' $file
        done
        shift
      done

      GLOBIGNORE=$ORIG_GLOBIGNORE
    fi
  }
  gg_dasherize() {
    gg_replace $1 `echo $1 | sed -e 's/_/-/g'` $2
  }

Here's a case-insensitive version:

gg_ireplace() {
  if [[ "$#" == "0" ]]; then
    echo 'Usage:'
    echo '  gg_ireplace term replacement file_mask'
    echo
    echo 'Example:'
    echo '  gg_ireplace cappuccino Cappuccino *.html'
    echo
  else
    find=$1; shift
    replace=$1; shift

    ORIG_GLOBIGNORE=$GLOBIGNORE
    GLOBIGNORE=*.*

    if [[ "$#" = "0" ]]; then
      set -- ' ' $@
    fi

    while [[ "$#" -gt "0" ]]; do
      for file in `git grep -Fil $find -- $1`; do
        perl -pi -w -e "s/\Q$find\E/$replace/gi;" $file
      done
      shift
    done

    GLOBIGNORE=$ORIG_GLOBIGNORE
  fi
}

Note the following, you may want to update your original script:

• Perl used for the regex, which allows for case-insensitive option i
• Perl has \Q...\E, which allows us to make the $find match literal
• Usage of git grep -F for fixed-length string matching, makes initial search a bit faster

Also note that BSD sed command does not support the i option... I don't know if there is any way to do this without Perl.

Odd, I get (on Mac) sed: -i may not be used with stdin. Changing -i'' to -i '' (with a space) fixes this, which makes sense: -i'' is exactly equivalent to -i, I think, so it's treating $file as the extension.

Here is my version that I use on Mac that handles filenames with 'Spaces'.

gg_replace() {
    if [[ "$#" == "0" ]]; then
        echo 'Usage:'
        echo '  gg_replace term replacement file_mask'
        echo
        echo 'Example:'
        echo '  gg_replace cappuchino cappuccino *.html'
        echo
    else
        find=$1; shift
        replace=$1; shift

        ORIG_GLOBIGNORE=$GLOBIGNORE
        GLOBIGNORE=*.*

        if [[ "$#" = "0" ]]; then
            set -- ' ' $@
        fi

        while [[ "$#" -gt "0" ]]; do
            for file in `git grep -l $find -- $1 | sed -e "s/ /~~~~~/g"`; do
                sed -i "" -e "s/$find/$replace/g" "${file/~~~~~/ }"
            done
            shift
        done

        GLOBIGNORE=$ORIG_GLOBIGNORE
    fi
}

just a small tip for those trying to use this on OS X: install GNU sed (brew install gnu-sed) and replace the sed call with gsed

Here's my version: https://gist.github.com/glyph/9beafa8a7b26e5ca9f6666448fa5810d

gg_replace() {
    if [[ "$#" -lt "2" ]]; then
        echo "
Usage:
  $0 term replacement file_mask
Example:
  $0 cappuchino cappuccino '*.html'
";
    else
        local find="$1"; shift;
        local replace="$1"; shift;
        git grep -zlI "${find}" -- "$@" |
            xargs -0 sed -e "s/${find}/${replace}/g" -i '' ;
    fi;
}

A few notes:

• passes shellcheck
• doesn't depend on word splitting so doesn't need to monkey with GLOBIGNORE
• supports spaces, newlines, and (apropos of dawalama's version ;-)) ~~~~~ in path names
• it still has the problem described in dwheeler's https://dwheeler.com/essays/filenames-in-shell.html section 3.3, since I couldn't figure out a quick way to make git grep prefix all its output with ./
• it's a bit faster since it doesn't spawn new sed processes quite so many times