Recursively search files named string.xml for certain text

You'll want to use find for this, since grep won't work that way recursively (as far as I know). Something like this should work:

find . -name "strings.xml" -exec grep "text" "{}" \;

The find command searches starting in the current directory (.) for a file with the name strings.xml (-name "strings.xml"), and then for each found file, execute the grep command specified. The curly braces ("{}") are a placeholder that find uses to specify the name of the file it found. More detail can be found in man find.

Also note that the -r option to grep is no longer necessary, since find works recursively.

You can use the grep command:

grep -r "text" /path/to/dir/strings.xml