#!/bin/bash

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

gitgrep "\bawk\b.*-F([[:space:]]|[[:space:]]*[\"'][^\"']{2,})" \
    'awk with -F char or -F ERE, use -Fchar instead (Solaris)'
    
gitgrep '\bsed\b.*\\[?+]' \
    'sed with ? or +, use POSIX BRE instead (\{m,n\})'

gitgrep '\bsed\b.*(\(\\?\||\|\\?\))' \
    "sed with empty alternative in parens, use '\(...\)\{0,1\}' instead"

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

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

gitgrep '\b[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)