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I'm trying to do a text search in some files that share a similar directory structure, but are not in the same directory tree, in GNU/Linux.

I have a web server with many sites that share the same tree structure (Code Igniter MVC PHP framework), so I want to search in a specific directory down the tree for each site, example:


Where * is the site name. And from those application directories, I want to search all the tree down to its leaves, for an *.php file that has some text pattern inside, let's say "debug(", no regular expression needed.

I know how to use find and grep but I'm not good at combining them.

How would I do this?
Thanks in advance!

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up vote 18 down vote accepted


find /srv/www/*/htdocs/system/application/ -name "*.php" -exec grep "debug (" {} \; -print

This should recursively search the folders under application for files with .php extension and pass them to grep.

An optimization on this would be to execute:

find /srv/www/*/htdocs/system/application/ -name "*.php" -print0 | xargs -0 grep -H "debug ("

This uses xargs to pass all the .php files output by find as arguments to a single grep command e.g grep "debug (" file1 file2 file3. The -print0 option of find and -0 option of xargs ensure the spaces in file and directory names are correctly handled. The -H option passed to grep ensures that the filename is printed in all situations. (By default, grep prints the filename only when multiple arguments are passed in.)

From man xargs:

   -0     Input items are terminated by a null character instead of by whitespace, and the quotes and  backslash
          are  not  special  (every  character  is  taken literally).  Disables the end of file string, which is
          treated like any other argument.  Useful when input items might contain white space, quote  marks,  or
          backslashes.  The GNU find -print0 option produces input suitable for this mode.
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+1. That will execute grep for each php file, though. If there are lots of files, you can optimize further by find /srv/www/*/htdocs/system/application/ -name "*.php" -print0 | xargs -0 grep "debug (" – Jukka Matilainen Sep 24 '09 at 13:45
@jackem Agreed. I'll update my answer accordingly. – nagul Sep 24 '09 at 14:38
Another small improvement: xargs may just pass one filename to grep, in which case grep won't show the filename if there's a match. You may want to add -H to the grep command to force it to show the filename. – Randy Orrison Sep 24 '09 at 14:54
@Randy That's a very valid point. – nagul Sep 24 '09 at 15:13
This is true necromancy, but GNU find can take the + operator instead of \; to perform the same sort of single process execution that xargs do. Thus, find /srv/www/*/htdocs/system/application/ -name "*.php" -exec grep -H "debug (" {} + does the same thing as the xargs example in this answer, but with one less process fork (and still 0 risk for file name troubles). – Daniel Andersson May 10 '12 at 13:22

find is not even needed for this example, one can use grep directly (at least GNU grep):

grep -RH --include='*.php' "debug (" /srv/www/*/htdocs/system/application/

and we are down to a single process fork.

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