grep, but only certain file extensions

Question

I am working on writing some scripts to grep certain directories, but these directories contain all sorts of file types.

I want to grep jus

Answer 1

Since this is a matter of finding files, let's use find!

Using GNU find you can use the -regex option to find those files in the tree of directories whose extension is either .h or .cpp:

find -type f -regex ".*\.\(h\|cpp\)"
#            ^^^^^^^^^^^^^^^^^^^^^^^

Then, it is just a matter of executing grep on each of its results:

find -type f -regex ".*\.\(h\|cpp\)" -exec grep "your pattern" {} +

If you don't have this distribution of find you have to use an approach like Amir Afghani's, using -o to concatenate options (the name is either ending with .h or with .cpp):

find -type f \( -name '*.h' -o -name '*.cpp' \) -exec grep "your pattern" {} +
#            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

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And if you really want to use grep, follow the syntax indicated to --include:

grep "your pattern" -r --include=*.{cpp,h}
#                      ^^^^^^^^^^^^^^^^^^^