for-sed-grep script, this is used to replace a string in a set of files without doing sed n-times

fsg.sh

#!/bin/bash
# for-grep-sed script used to match a string and replace it in set of files
FGS_FIELD=$1;
FGS_FIELD_REPLACEMENT=$2;

for mf in `grep -rn ${FGS_FIELD} --include=\*.{xml,py} | tr ":" " " | awk '{print $1}' | uniq`; do
    sed_replace="sed -i 's/${FGS_FIELD}/${FGS_FIELD_REPLACEMENT}/g' ${mf}";
    eval $sed_replace;
done

unset FGS_FIELD;
unset FGS_FIELD_REPLACEMENT;