How do I grep recursively?

Question

How do I recursively grep all directories and subdirectories?

find . | xargs grep "texthere" *

Answer 1

Or install ack, if you want a much faster way and are doing this a lot.

Answer 2

Here's a recursive (tested lightly with bash and sh) function that traverses all subfolders of a given folder ($1) and using grep searches for given string ($3) in given files ($2):

$ cat script.sh
#!/bin/sh

cd "$1"

loop () {
    for i in *
    do
        if [ -d "$i" ]
        then
            # echo entering "$i"
            cd "$i"
            loop "$1" "$2"
        fi
    done

    if [ -f "$1" ]
    then
        grep -l "$2" "$PWD/$1"
    fi

    cd ..
}

loop "$2" "$3"

Running it and an example output:

$ sh script start_folder filename search_string
/home/james/start_folder/dir2/filename

Answer 3

ag is my favorite way to do this now github.com/ggreer/the_silver_searcher . It's basically the same thing as ack but with a few more optimizations.

Here's a short benchmark. I clear the cache before each test (cf https://askubuntu.com/questions/155768/how-do-i-clean-or-disable-the-memory-cache )

ryan@3G08$ sync && echo 3 | sudo tee /proc/sys/vm/drop_caches
3
ryan@3G08$ time grep -r "hey ya" .

real    0m9.458s
user    0m0.368s
sys 0m3.788s
ryan@3G08:$ sync && echo 3 | sudo tee /proc/sys/vm/drop_caches
3
ryan@3G08$ time ack-grep "hey ya" .

real    0m6.296s
user    0m0.716s
sys 0m1.056s
ryan@3G08$ sync && echo 3 | sudo tee /proc/sys/vm/drop_caches
3
ryan@3G08$ time ag "hey ya" .

real    0m5.641s
user    0m0.356s
sys 0m3.444s
ryan@3G08$ time ag "hey ya" . #test without first clearing cache

real    0m0.154s
user    0m0.224s
sys 0m0.172s

Answer 4

Below are the command for search a String recursively on Unix and Linux environment.

for UNIX command is:

find . -name "string to be searched" -exec grep "text" "{}" \;

for Linux command is:

grep -r "string to be searched" .

Answer 5

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.

Answer 6

Also:

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

but grep -r is a better answer.