sedfile

#!/bin/bash

# wrapper for 'sed -i': fail if file was not modified by sed

set -ueo pipefail

HASHTOOL="sha1sum"

if [ $# -lt 1 ]; then
        echo "Error: No file given."
        echo
        exit 1
fi >&2

# get last argument
FILE=${*: -1}

OLD=$($HASHTOOL "$FILE")
sed "$@"
NEW=$($HASHTOOL "$FILE")

# fail if file was not modified
if [ "$OLD" == "$NEW" ]; then
        echo "Error: sed $*"
        exit 1
fi >&2
exit 0