[grep] How to grep recursively, but only in files with certain extensions?

I'm working on a script to grep certain directories:

{ grep -r -i CP_Image ~/path1/;
grep -r -i CP_Image ~/path2/;
grep -r -i CP_Image ~/path3/;
grep -r -i CP_Image ~/path4/;
grep -r -i CP_Image ~/path5/; } 
| mailx -s GREP [email protected]

How can I limit results only to extensions .h and .cpp?

There is no -r option on HP and Sun servers, this way worked for me on my HP server

find . -name "*.c" | xargs grep -i "my great text"

-i is for case insensitive search of string

grep -rnw "some thing to grep" --include=*.{module,inc,php,js,css,html,htm} ./

ag (the silver searcher) has pretty simple syntax for this

       -G --file-search-regex PATTERN
          Only search files whose names match PATTERN.

so

ag -G *.h -G *.cpp CP_Image <path>

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" {} +
#            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

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

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

I am aware this question is a bit dated, but I would like to share the method I normally use to find .c and .h files:

tree -if | grep \\.[ch]\\b | xargs -n 1 grep -H "#include"

or if you need the line number as well:

tree -if | grep \\.[ch]\\b | xargs -n 1 grep -nH "#include"

Some of these answers seemed too syntax-heavy, or they produced issues on my Debian Server. This worked perfectly for me:

grep -r --include=\*.txt 'searchterm' ./

...or case-insensitive version...

grep -r -i --include=\*.txt 'searchterm' ./

• grep: command

• -r: recursively

• -i: ignore-case

• --include: all *.txt: text files (escape with \ just in case you have a directory with asterisks in the filenames)

• 'searchterm': What to search

• ./: Start at current directory.

Source: PHP Revolution: How to Grep files in Linux, but only certain file extensions?

The below answer is good:

grep -r -i --include \*.h --include \*.cpp CP_Image ~/path[12345] | mailx -s GREP [email protected]

But can be updated to:

grep -r -i --include \*.{h,cpp} CP_Image ~/path[12345] | mailx -s GREP [email protected]

Which can be more simple.

How about:

find . -name '*.h' -o -name '*.cpp' -exec grep "CP_Image" {} \; -print

Should write "-exec grep " for each "-o -name "

find . -name '*.h' -exec grep -Hn "CP_Image" {} \; -o -name '*.cpp' -exec grep -Hn "CP_Image" {} \;

Or group them by ( )

find . \( -name '*.h' -o -name '*.cpp' \) -exec grep -Hn "CP_Image" {} \;

option '-Hn' show the file name and line.

If you want to filter out extensions from the output of another command e.g. "git":

files=$(git diff --name-only --diff-filter=d origin/master... | grep -E '\.cpp$|\.h$')

for file in $files; do
    echo "$file"
done

The easiest way is

find . -type  f -name '*.extension' 2>/dev/null | xargs grep -i string 

Edit: add 2>/dev/null to kill the error output

To include more file extensions and grep for password throughout the system:

find / -type  f \( -name '*.conf' -o -name "*.log" -o -name "*.bak" \) 2>/dev/null |
xargs grep -i password