#!/bin/rc
# ogrep: "grep -o"
#        -S: use sam which supports \n in regexp but is slower
rfork e
fn usage{
	echo 'usage: ogrep [ -S ] pattern [ file ... ]' >[1=2]
	exit usage
}
sam=0
while(~ $1 -*){
	switch($1){
	case -S; sam=1
	case *; usage
	}
	shift
}
if(~ $#* 0) usage
pat=$1
shift
if(~ $sam 1){
	ssam '	y/'$pat'/ c/\n/
		1d' $*
	exit
}
pat=`{echo $pat | sed 's/\\/\\\\/g'}
awk '
BEGIN {
	pat = "'$"pat'"
}
{
	s = $0
	while((p = match(s, pat)) != 0) {
		print substr(s, p, RLENGTH)
		s = substr(s, p + RLENGTH)
	}
}
' $*