#!/bin/sh

# $0 string1 string2 file1 .. filen
#
if [ $# -lt 3 ]; then
    echo "Usage: `basename $0` [-f] <string1> <string2> <file1> .. <filen>"
    echo ""
    echo "Replaces all occurrences of string1 by string2 in files."
    echo "(replacement of sed -i on those systems that don't support it)"
    exit 1
fi

FROMSTRING=$1
shift
TOSTRING=$1
shift

for f in $*
do
    if grep "$FROMSTRING" "$f" >/dev/null
    then
        cp "$f" "${f}_bak"
        sed -e "s@$FROMSTRING@$TOSTRING@g" "${f}"_bak > "$f"
        rm -f "${f}"_bak
    #else
    #    echo "String $FROMSTRING not present in $f"
    #fi
done