#!/usr/bin/env zsh

if [ $# -gt 2 ] || [ $# -lt 1 ] || [ "$1" = "-h" ]; then
	cat <<EOF
Usage: ${0##*/} FILE [STRING]

Append to all STRING found in FILE a secret phrase being prompted.  If STRING is
omitted, secret phrase will be appended to the end of the file.  If FILE does
not exist, it will be created and secret phrase will be inserted. STRING will be
ignored.

This requires 'read -s'. As of Oct 6 2013 it will not work for strictly
POSIX-compliant shells.

This is a stupid program, don't use it.

EOF
	exit
fi

FILE="$1"
STRING=""
DUMMY=""

if [ $# -eq 2 ]; then
	STRING="$2"
fi

echo -n "Secret: "
read -s DUMMY
echo ""

if [ ! -e "$FILE" ] || [ -z "$STRING" ]; then
	echo "$DUMMY" >> "$FILE"
	echo "Secret appended to ${FILE} at the end."
	exit
fi


if [ $# -eq 1 ]; then
	echo "$DUMMY" >> "$FILE"
else
	ex -sc "%s/${STRING}/${STRING}${DUMMY}/g|xit" "${FILE}"
fi
echo "Secret appended to ${FILE}."