#!/bin/bash

function input
{
cat << \EOF
abc
def
this is foobar
ghi
jki
more foobar
blee
blah
bleach
EOF
}

input | ./context-split -s '^.*foobar.*$' -i

if [ $(ls ? | wc -l) = 3 ]
then
    rm -f ?
    exit 0
else
    echo "$0: Did not find 3 subfiles" 1>&2
    exit 1
fi