bashgit

Search string only in added or removed lines using git pickaxe

I can search a string in changes with git log -S "text to find" --stat. How can I do a similar search, except look for the string in only added or removed lines (not both)?

There is a --diff-filter option but looks like it filters the whole file rather than individual lines.

UPDATE
I've crafted a bash script based on @LeGEC's answer. It's pretty overengineered and rather inefficient (especially on cygwin) but it works well.

Save the following script as a file named git-xlog if you like Git to pick it up as an xlog sub-command. Don't forget to set the executable bit on linux.

Example:
git xlog --diff-type=added --log-opt='--author=someone -S "sometext"' --diff-opt='--stat'

#!/usr/bin/env bash

app_name="$(basename "${BASH_SOURCE[0]}")"

USAGE=$(cat << EOF
Usage:
    $app_name
        Search history for string only in added or removed lines.

Options:
    -t, --diff-type=<A|R|Added|Removed>
        Whether to search in added or removed lines.

    -l, --log-opt=<LOG_OPTIONS>
        Options to pass on to git log commands.

    -d, --diff-opt=<DIFF_OPTIONS>
        Options to pass on to git diff commands.

    --help
        Show this help information and exit.
EOF
)

getopt -q -T
if [[ $? -ne 4 ]]; then
    echo "$app_name: This script requires an enhanced getopt version." >&2
    exit 1
fi

opts=$(getopt -o 't:l:d:' --long 'help,diff-type:,log-opt:,diff-opt:' -n "$app_name" -- "$@") || exit $?

eval "opts=($opts)"

for ((i=0; i < ${#opts[@]}; i++)); do
    opt="${opts[$i]}"
    case "$opt" in
        --help)
            echo "$USAGE"
            exit 0
            ;;
        -t|--diff-type)
            diff_type="${opts[++i]}"
            ;;
        -l|--log-opt)
            log_opt="${opts[++i]}"
            ;;
        -d|--diff-opt)
            diff_opt="${opts[++i]}"
            ;;
        --)
            break
            ;;
        *)
            echo 'Internal error!' >&2
            exit 1
            ;;
    esac
done

if [[ ! -v diff_type ]]; then
    echo "$app_name: Missing '--diff-type' argument." >&2
    exit 1
elif [[ -z $diff_type ]]; then
    echo "$app_name: Missing value for argument '--diff-type'." >&2
    exit 1
elif [[ ${diff_type@U} == 'A' || ${diff_type@U} == "ADDED" ]]; then
    diff_mark='>'
elif [[ ${diff_type@U} == 'R' || ${diff_type@U} == "REMOVED" ]]; then
    diff_mark='<'
else
    echo "$app_name: Unrecognized diff-type: '$diff_type'. Accepted values: 'A', 'Added', 'R', 'Removed'." >&2
    exit 1
fi

if [[ ! -v log_opt ]]; then
    echo "$app_name: Missing '--log-opt' argument." >&2
    exit 1
elif [[ -z $log_opt ]]; then
    echo "$app_name: Missing value for argument '--log-opt'." >&2
    exit 1
fi

opts=$(eval getopt -q -o 'S:G:' -n "$app_name" -- "$log_opt")

eval "opts=($opts)"

for ((i=0; i < ${#opts[@]}; i++)); do
    opt="${opts[$i]}"
    case "$opt" in
        -S)
            search_text="${opts[++i]}"
            ;;
        -G)
            search_regex="${opts[++i]}"
            ;;
        --)
            break
            ;;
        *)
            echo 'Internal error!' >&2
            exit 1
            ;;
    esac
done

if [[ ! -v search_text && ! -v search_regex ]]; then
    echo "$app_name: No '-S' or '-G' found in log options." >&2
    exit 1
elif [[ -z $search_text && -z $search_regex ]]; then
    echo "$app_name: Missing value for argument '-S' or '-G' in log options." >&2
    exit 1
fi

trap interrupt INT

interrupt () {
    echo "$app_name: Interrupted." >&2
    exit 1
}

if [[ -t 1 ]]; then 
    git_color="--color"
    less_color="-r"
fi

if [[ -n $search_regex ]]; then
    grep_opt='-E "$search_regex"'
elif [[ -n $search_text ]]; then
    grep_opt='"$search_text"'
fi

set -e

eval git log "$log_opt" --no-patch --format=%H |
while read -r sha; do
    eval git diff -U0 "$sha~" "$sha" --output-indicator-new='\>' --output-indicator-old='\<' |
    grep -E "^$diff_mark" |
    eval grep -q "$grep_opt" &&
    eval git --no-pager log "$git_color" --no-walk "$sha" "$log_opt" "$diff_opt"
done | less -deFX $less_color
Solution

  • There is no built-in way to do that.

    The closest thing I think of would be to first run git log -S "text" ... to identify commits, then scan the diffs:

    # get a list of commit hashes from 'git log':
git log --format=%H -S "text" |
# for each commit: do some processing on the diff:
while read sha; do
    git diff -U0 -S "text" "$sha"~ "$sha"  |
      # process ... count number of additions/deletions, and print the
      # information you want
done

    note that: