#!/bin/bash -u

gitgrep()
{
    local out=$(git grep -I -P -n "$1" |
        grep -E '^(bash_completion|completions/|test/)' |
        grep -Ev "^test/runLint\>${filter_out:+|$filter_out}")
    if [ -n "$out" ]; then
        printf '***** %s\n' "$2"
        printf '%s\n\n' "$out"
    fi
}

unset CDPATH
cd $(dirname "$0")/..

cmdstart='(^|[[:space:]]|\()'
filter_out=

gitgrep $cmdstart"awk\b.*-F([[:space:]]|[[:space:]]*[\"'][^\"']{2,})" \
    'awk with -F char or -F ERE, use -Fchar instead (Solaris)'

gitgrep $cmdstart"awk\b.*\[:[a-z]*:\]" \
    'awk with POSIX character class not supported in mawk (Debian/Ubuntu)'

gitgrep $cmdstart'sed\b.*\\[?+]' \
    'sed with ? or +, use POSIX BRE instead (\{m,n\})'

gitgrep $cmdstart'sed\b.*\\\|' \
    "sed with \|, use POSIX BRE (possibly multiple sed invocations) or another tool instead"

# TODO: really nonportable? appears to work fine in Linux, FreeBSD, Solaris
#gitgrep $cmdstart'sed\b.*;' \
#    'sed with ;, use multiple -e options instead (POSIX?) (false positives?)'

gitgrep $cmdstart'sed\b.*[[:space:]]-[^[:space:]]*[rE]' \
    'sed with -r or -E, drop and use POSIX BRE instead'

gitgrep $cmdstart'[ef]grep\b' \
    '[ef]grep, use grep -[EF] instead (historical/deprecated)'

# TODO: $ in sed subexpression used as an anchor (POSIX BRE optional, not in
#       Solaris/FreeBSD)

gitgrep '(?<!command)'$cmdstart'(grep|ls|sed)(\s|$)' \
    'invoke grep, ls, and sed through "command", e.g. "command grep"'

gitgrep '<<<' 'herestrings use temp files, use some other way'

filter_out='^(test/|bash_completion\.sh)' gitgrep ' \[ ' \
    'use [[ ]] instead of [ ]'