Do the following:
grep -rnw '/path/to/somewhere/' -e 'pattern'
-r or -R is recursive,
-n is line number, and
-w stands for match the whole word.
-l (lower-case L) can be added to just give the file name of matching files.
Along with these, --exclude, --include, --exclude-dir flags could be used for efficient searching:
This will only search through those files which have .c or .h extensions:
grep --include=\*.{c,h} -rnw '/path/to/somewhere/' -e "pattern"
This will exclude searching all the files ending with .o extension:
grep --exclude=*.o -rnw '/path/to/somewhere/' -e "pattern"
For directories it's possible to exclude a particular directory(ies) through --exclude-dir parameter. For example, this will exclude the dirs dir1/, dir2/ and all of them matching *.dst/:
grep --exclude-dir={dir1,dir2,*.dst} -rnw '/path/to/somewhere/' -e "pattern"
This works very well for me, to achieve almost the same purpose like yours.
For more options check man grep.