grep.sh

#! /bin/sh

# this is trying to mimick parts of GNU grep with busybox grep.
# We convert long arguments to short ones basically.

# this is all that busybox grep supports (with the GNU long argument version)

# -H --with-filename
# -h --no-filename
# -n --line-number
# -l
# -L --files-without-matches
# -c --count
# -o --only-matching
# -q --quiet --silent
# -v --invert-match
# -s --no-messages
# -r --recursive
# -R --dereference-recursive
# -i --ignore-case
# -w --word-regexp
# -x --line-regexp
# -F --fixed-strings
# -E --extended-regexp
# -m --max-count=NUM
# -A --after-context=NUM
# -B --before-context=NUM
# -C --context=NUM
# -e --regexp=PATTERNS
# -f --file=FILE

check_option_requires_arg() {
	case "$1" in
	(-[mABCef]|--max-count|--after-context|--before-context|--context|--regexp|--file)
		false;;
	(*)	true;;
	esac
}

replace_option() {
	case "$1" in
	(--with-filename) new=-H;;
	(--no-filename) new=-h;;
	(--line-number) new=-n;;
	(--files-without-matches) new=-L;;
	(--count) new=-c;;
	(--only-matching) new=-o;;
	(--quiet|--silent) new=-q;;
	(--invert-match) new=-v;;
	(--no-messages) new=-s;;
	(--recursive) new=-r;;
	(--dereference-recursive) new=-R;;
	(--ignore-case) new=-i;;
	(--word-regexp) new=-w;;
	(--line-regexp) new=-x;;
	(--fixed-strings) new=-F;;
	(--extended-regexp) new=-R;;
	(--max-count) new=-m;;
	(--after-context) new=-A;;
	(--before-context) new=-B;;
	(--context) new=-C;;
	(--regexp) new=-e;;
	(--file) new=-f;;
	(*) new="$1";;
	esac
}

i=$#
while [ $i -gt 0 ]; do
	case "$1" in
		(*=*)
			replace_option "${1%%=*}"
			set -- "$@" "$new" "${1#*=}"
		;;
		(*)
			replace_option "$1"
			set -- "$@" "$new"
			if ! check_option_requires_arg "$1" ;then
				i=$(( $i -1))
				shift; set "$@" "$1"

			fi
		;;
	esac
	i=$(( $i -1))
	shift
done

echo "$# args: $*"
# grep "$@"