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?

Question

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?

Solution 1

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

Solution 2

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

grep hello *.h *.cc

Solution 3

To search in current directory recursively:

grep -r 'myString' .

Solution 4

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

Check the manual pages for find and xargs for details.

Solution 5

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)$'`

View more solutions

Comments

[stackoverflow]

I need all sub directories also

[Donald Miner]

Adding -R doesn't work unfortunately. It expands the * before going recursively.

[Donald Miner]

Noufal's answer is what you are looking for if you need subdirectories

[Jonathan Leffler]

You have to have a -print0 after the '*.cc' as otherwise you don't have an action for that part of the search. Or you have to insert parentheses in there: find . \( -name '*.cc' -or -name '*.h' \) -print0.

[Noufal Ibrahim]

Thanks for noticing that. I've edited the answer to "fix" it.

[jordanm]

You can also use the find -exec + syntax instead of xargs

[Jonathan Leffler]

@jordanm: Yes: -exec grep "hello" {} + where the pair of braces represents the file name(s). Good suggestion.

[jordanm]

@Jammin You should be clear about that when asking the question. This answer is the "correct" answer to your stated question.

[Admin]

$ grep -R hello * # find from all the word contain hello (including sub directory)

[Andrew Swift]

I know how to use google etc. I asked it here because several answers have "-l" and it's nice to have all the information in one place.

[kon psych]

This doesn't display only .h or .cc files and it is useful to explain which options you used and why.

[fedorqui]

note you can also say find ... -exec grep "hello" {} +

[Rex Charles]

-l (Lowercase "el") Suppresses normal output. Prints the name of each input file from which output would normally have been printed. The scanning/searching will stop on the first match.

[jbobbins]

In the original post you said "current directory" and nothing about needing it recursively or in sub directories (I realize you mentioned it in a later post). For those interested in how to do it only in the current directory, it's grep -si "hello" --include=*.{cc,h} ./* ./.*(searches hidden files as well). Here's a generic version to search for a string in all/hidden files: grep -s "hello" * .* . Maybe most generally useful (and simplest), this searches all non-hidden files for "hello": grep -si "hello" ./* Thanks to this post: askubuntu.com/a/777456

[Admin]

grep -r --include=*.{java,py} "hello" .

[xApple]

For some reason this doesn't work on macOS, even when using the GNU grep utility.