find -print0 | xargs -0 grep not working as expected on Ubuntu 10.04

Question

I've got a bit of a weird issue.

If I run:

find . -iname '*.php' -o -iname '*.pl' -o -iname '*.html' | xargs grep -i users

I get a load of errors for filenames containing spaces, but also some files match.

However, if I try the following so filenames with spaces in are correctly handled, no matches are returned:

find . -iname '*.php' -o -iname '*.pl' -o -iname '*.html' -print0 | xargs -0 grep -i users

What am I doing wrong? The second command should return me at least the same matching files as the first, but I don't get any matches.

Why don't you just add -exec grep -i users {} \; instead of using xargs ?
It still doesn't work. It works without the additional -o -iname '.pl' -o -iname '.html' clause though

user1491250 · Answer 1 · 2012-11-09 15:38:55Z

up vote 1 down vote

And the answer is:

find . \( -iname '*.php' -o -iname '*.pl' -o -iname '*.html' \) -print0 | xargs -r0 grep -i users

This works. I hadn't seen it before but a colleague told me about it.

answered Nov 9 '12 at 15:38

user1491250

	Or `-iname '.php' -print0 -o -iname '.pl' -print0 ...`... – Jonathan Leffler Nov 9 '12 at 15:44
	You could also use `\( -iname '*.php' ... \) -exec grep -i users +`, where the plus means 'build up a command line like `xargs` without needing to use `xargs`'. Using a semi-colon `\;` would mean execute `grep` for each file as it is found. – Jonathan Leffler Nov 9 '12 at 15:46

jlliagre · Answer 2 · 2012-11-09 16:20:28Z

up vote 0 down vote

You don't need print0 and xargs, this functionality is already built in find:

find . -iname "*.php" -o -iname "*.pl" -o -iname "*.html" -exec grep -i users {} +

answered Nov 9 '12 at 16:20

jlliagre
4,044413

migrated from stackoverflow.com Nov 10 '12 at 0:05