List "tags" (TODO etc.) found in inline comments

list_tags.sh

#!/bin/sh

# List code "tags" (TODO et al.) present in source files within given directory
#
# :author: Karol Kuczmarski "Xion"
# :license: Public Domain


TAGS="TODO FIXME XXX"

HASH_COMMENT_LANGS="pl py rb sh"
SLASH_COMMENT_LANGS="c cc cpp cs d h hh hpp go java js rs"

COMMON_GREP_OPTIONS="--recursive --binary-files=without-match --devices=skip"
GREP_AFTER=3


main() {
    local dir="${1-.}"

    # use pcregrep-based function if available; otherwise fallback to regular grep
    local ls_tags
    if command -v pcregrep >/dev/null 2>&1 ; then
        ls_tags=pcregrep_tag
    else
        echo >&2 "pcregrep not available -- using regular grep with --after=$GREP_AFTER"
        ls_tags=grep_tag
    fi

    for tag in $TAGS; do
        for lang in $HASH_COMMENT_LANGS; do
            $ls_tags "#" "$tag" "$lang" "$dir"
        done
        for lang in $SLASH_COMMENT_LANGS; do
            $ls_tags "//" "$tag" "$lang" "$dir"
        done
    done
}

grep_tag() {
    local prefix="$1" ; local tag="$2" ; local lang="$3" ; local dir="$4"
    grep $COMMON_GREP_OPTIONS
        --include="*.$lang" --exclude-dir=".*" \
        --after="$GREP_AFTER" --line-number \
        "$prefix\s*$tag\b" \
        "$dir"
}

pcregrep_tag() {
    local prefix="$1" ; local tag="$2" ; local lang="$3" ; local dir="$4"
    (
        export PCREGREP_COLOR="1;32"  # green text
        pcregrep $COMMON_GREP_OPTIONS \
            --include=".*\.$lang" --exclude-dir="\..*" \
            --line-number --color --multiline \
            "$prefix\\s*$tag\\b.*\n?([ \t]*$prefix.*\n)*" \
            "$dir"
    )
}


main "$@"