How do I use grep to search the current directory for all files having the a string "hello" yet display only .h and .cc files?

How do I use grep to search the current directory for any and all files containing the string "hello" and display only .h and .cc files?

grep -r --include=*.{cc,h} "hello" .

This reads: search recursively (in all sub directories also) for all .cc OR .h files that contain "hello" at this . (current) directory

From another stackoverflow question

You can pass in wildcards in instead of specifying file names or using stdin.

grep hello *.h *.cc

To search in current directory recursively:

grep -r 'myString' .

find . -name \*.cc -print0 -or -name \*.h -print0 | xargs -0 grep "hello".

Check the manual pages for find and xargs for details.

If I read your question carefully, you ask to "grep to search the current directory for any and all files containing the string "hello" and display only .h and .cc files". So to meet your precise requirements here is my submission:

This displays the file names:

grep -lR hello * | egrep '(cc|h)$'

...and this display the file names and contents:

grep hello `grep -lR hello * | egrep '(cc|h)$'`

If you need a recursive search, you have a variety of options. You should consider ack.

Failing that, if you have GNU find and xargs:

find . -name '*.cc' -print0 -o -name '*.h' -print0 | xargs -0 grep hello /dev/null

The use of /dev/null ensures you get file names printed; the -print0 and -0 deals with file names containing spaces (newlines, etc).

If you don't have obstreperous names (with spaces etc), you can use:

find . -name '*.*[ch]' -print | xargs grep hello /dev/null

This might pick up a few names you didn't intend, because the pattern match is fuzzier (but simpler), but otherwise works. And it works with non-GNU versions of find and xargs.

grep -l hello **/*.{h,cc}

You might want to shopt -s nullglob to avoid error messages if there are no .h or no .cc files.

The simplest way : grep -Ril "Your text" /