How to use "grep" command to find text including subdirectories

I want to find all files which contain a specific string of text. The grep command works, but I don't know how to use it for every directory (I can only do it for my current directory). I tried reading man grep, but it didn't yield any help.

Solution 1:

It would be better to use

grep -rl "string" /path

where

• -r (or --recursive) option is used to traverse also all sub-directories of /path, whereas
• -l (or --files-with-matches) option is used to only print filenames of matching files, and not the matching lines (this could also improve the speed, given that grep stop reading a file at first match with this option).

Solution 2:

If you're looking for lines matching in files, my favorite command is:

grep -Hrn 'search term' path/to/files

• -H causes the filename to be printed (implied when multiple files are searched)
• -r does a recursive search
• -n causes the line number to be printed

path/to/files can be . to search in the current directory

Further options that I find very useful:

• -I ignore binary files (complement: -a treat all files as text)
• -F treat search term as a literal, not a regular expression
• -i do a case-insensitive search

• --color=always to force colors even when piping through less. To make less support colors, you need to use the -r option:

  grep -Hrn search . | less -r
  

• --exclude-dir=dir useful for excluding directories like .svn and .git.

Solution 3:

I believe you can use something like this:

find /path -type f -exec grep -l "string" {} \;

Explanation from comments

find is a command that lets you find files and other objects like directories and links in subdirectories of a given path. If you don't specify a mask that filesnames should meet, it enumerates all directory objects.

• -type f specifies that it should process only files, not directories etc.
• -exec grep specifies that for every found file, it should run the grep command, passing its filename as an argument to it, by replacing {} with the filename

Solution 4:

My default command is

grep -Rin string *

I use a capitol 'R' because ls uses it for recursive. Since grep accepts both, no reason to not use it.

EDIT: per HVNSweeting, apparently -R will follow symlinks where as -r will not.

Solution 5:

If you’re willing to try something new, give ack a shot. The command to recursively search the current directory for string is:

ack string

Installation is quite simple:

curl http://betterthangrep.com/ack-standalone > ~/bin/ack && chmod 0755 !#:3

(Provided you’ve already got the directory ~/bin and it’s preferably in your PATH.)