How do I recursively grep all directories and subdirectories?

How do I recursively grep all directories and subdirectories?

find . | xargs grep "texthere" *

grep -r "texthere" .

The first parameter represents the regular expression to search for, while the second one represents the directory that should be searched. In this case, . means the current directory.

Note: This works for GNU grep, and on some platforms like Solaris you must specifically use GNU grep as opposed to legacy implementation. For Solaris this is the ggrep command.

If you know the extension or pattern of the file you would like, another method is to use --include option:

grep -r --include "*.txt" texthere .

You can also mention files to exclude with --exclude.

Ag

If you frequently search through code, Ag (The Silver Searcher) is a much faster alternative to grep, that's customized for searching code. For instance, it's recursive by default and automatically ignores files and directories listed in .gitignore, so you don't have to keep passing the same cumbersome exclude options to grep or find.

I now always use (even on Windows with GoW -- Gnu on Windows):

grep --include="*.xxx" -nRHI "my Text to grep" *

(As noted by kronen in the comments, you can add 2>/dev/null to void permission denied outputs)

That includes the following options:

--include=PATTERN

Recurse in directories only searching file matching PATTERN.

-n, --line-number

Prefix each line of output with the line number within its input file.

(Note: phuclv adds in the comments that -n decreases performance a lot so, so you might want to skip that option)

-R, -r, --recursive

Read all files under each directory, recursively; this is equivalent to the -d recurse option.

-H, --with-filename

Print the filename for each match.

-I     

Process a binary file as if it did not contain matching data;
this is equivalent to the --binary-files=without-match option.

And I can add 'i' (-nRHIi), if I want case-insensitive results.

I can get:

/home/vonc/gitpoc/passenger/gitlist/github #grep --include="*.php" -nRHI "hidden" *
src/GitList/Application.php:43:            'git.hidden'      => $config->get('git', 'hidden') ? $config->get('git', 'hidden') : array(),
src/GitList/Provider/GitServiceProvider.php:21:            $options['hidden'] = $app['git.hidden'];
tests/InterfaceTest.php:32:        $options['hidden'] = array(self::$tmpdir . '/hiddenrepo');
vendor/klaussilveira/gitter/lib/Gitter/Client.php:20:    protected $hidden;
vendor/klaussilveira/gitter/lib/Gitter/Client.php:170:     * Get hidden repository list
vendor/klaussilveira/gitter/lib/Gitter/Client.php:176:        return $this->hidden;
...

Also:

find ./ -type f -print0 | xargs -0 grep "foo"

but grep -r is a better answer.

globbing **

Using grep -r works, but it may overkill, especially in large folders.

For more practical usage, here is the syntax which uses globbing syntax (**):

grep "texthere" **/*.txt

which greps only specific files with pattern selected pattern. It works for supported shells such as Bash +4 or zsh.

To activate this feature, run: shopt -s globstar.

See also: How do I find all files containing specific text on Linux?

git grep

For projects under Git version control, use:

git grep "pattern"

which is much quicker.

ripgrep

For larger projects, the quickest grepping tool is ripgrep which greps files recursively by default:

rg "pattern" .

It's built on top of Rust's regex engine which uses finite automata, SIMD and aggressive literal optimizations to make searching very fast. Check the detailed analysis here.