#!/bin/sh
# mgrep: matches patterns across multiple lines.
# usage:  mgrep pattern [file]

PATH=/bin:/usr/bin:/usr/local/bin
export PATH

# Check the argument list.
case "$#" in
    0)  echo 'usage:  mgrep pattern [file]'; exit 1 ;;
    *)  ;;
esac

# Search for the pattern.
sed -e "N
h
s/ *\n/ /
/$1/{
g
p
d
}
g
D" $2

exit 0