42

Even when /tmp has no file called something, searching for it with find will return 0:

  $ find /tmp -name something 
  $ echo $?
  0

How can I get a non-zero exit status when find does not find anything?

41

Here is a one-liner that I believe does what you want:

find /tmp -name something | egrep '.*'

The return status will be 0 when something is found, and non-zero otherwise.

If you also need to capture the output of find for further processing, then Sven's answer has covered that.

  • 13
    The trailing * on the egrep regex is completely redundant. Since you are not using egrep regular expression syntax, plain old grep might be a few microseconds faster. – tripleee Oct 30 '15 at 13:03
11

Simplest solution that doesn't print, but exits 0 when results found

find /tmp -name something | grep -q "."
  • Double-quotes serve no purpose here. – haridsv Apr 10 at 15:16
10

Exit 0 is easy with find, exit >0 is harder because that usually only happens with an error. However we can make it happen:

if find -type f -exec false {} +
then
  echo 'nothing found'
else
  echo 'something found'
fi
  • 2
    As far as I can tell, this doesn't work. The exit code of find doesn't seem to depend on the exit codes of any -execs it ran. – Chris Dec 14 '17 at 14:51
  • @Chris works for me, and the 4 who upvoted – Steven Penny Dec 14 '17 at 15:41
  • example for wrongly false result of this solution: find /existing-starting-point /non-existing-starting-point -name file-in-existing-starting-point -exec false {} + – Gerald Schade Feb 15 at 17:11
  • This does work correctly, and is documented (although hidden in the exec section, not under return value). It canont differentiate between nothing found and find itself erroring out (e.g. when it was invoked on a non-existent starting point). – Tgr Apr 20 at 2:15
5

It's not possible. Find returns 0 if it exits successfully, even if it didn't find a file (which is a correct result not indicating an error when the file indeed doesn't exist).

To quote the find manpage

EXIT STATUS

find exits with status 0 if all files are processed successfully, greater than 0 if errors occur. This is deliberately a very broad description, but if the return value is non-zero, you should not rely on the correctness of the results of find.

Depending on what you want to achieve you could try to let find -print the filename and test against it's output:

#!/bin/bash
MYVAR=`find . -name "something" -print`
if [ -z "$MYVAR" ]; then
    echo "Notfound"
else
   echo $MYVAR
fi
  • It's certainly possible, although not as robust as one might want. – Ruslan Feb 19 '18 at 7:27
  • The manual page is poorly organized; what Ruslan said is documentated under the exec/execdir option (used with +): If any invocation returns a non-zero value as exit status, then find returns a non-zero exit status. – Tgr Apr 20 at 2:12
5

Having just found this question whilst trying to find my way to solve a problem with Puppet (change permissions on folders under a directory but not on the directory itself), this seems to work:

! test -z $(find /tmp -name something)

My specific use case is this:

! test -z $(find /home -mindepth 1 -maxdepth 1 -perm -711)

Which will exit code 1 if the find command finds no files with the required permissions.

  • A few solutions (didn't try them all) here didn't work on a Mac; this did. – Alex Hall Feb 8 at 7:24
1

I feel that this is the most concise and direct method:

test `find /tmp/ -name something -print -quit 2>/dev/null`
  • 2
    In this case, if find had an error it would print the result to /dev/null, return a non-zero exit, and then have that fixed to 0 by the test command. – Jeff Ferland Feb 6 '13 at 19:24
  • I don't believe that's true. Please describe your example. If there is an error and find exits, then the string will be empty and test will return non-zero. – danorton Feb 7 '13 at 18:10
  • I'm not sure what your example might be, but I accidentally omitted -print -quit, which might address your concern. – danorton Feb 7 '13 at 18:19
  • Perhaps the other person who downvoted (presumably for the same reason) can provide a contrary example? – danorton Feb 7 '13 at 22:04
  • 1
    Okay, you just don't like my style. For my use cases, any errors that find might report are either noise or so serious that they'll show up elsewhere. In any case, this method correctly answers the ultimate question: "Is there an accessible file in the path by the given name." An error will return a correct answer of "No". If I want to find out why not, I can add more complex code that answers questions not originally posed here. – danorton Feb 7 '13 at 22:31
0

Here's a little script I called test.py. It improves upon other methods posted in that it will return an error code if one is set, and it additionally set one if find didn't list any files:

from subprocess import Popen
import sys

p = Popen(['find'] + sys.argv)
out, err = p.communicate()
if p.returncode:
    sys.exit(p.returncode)
if not out:
    sys.exit(1)

Here's the command-line output:

$ python test.py . -maxdepth 1 -name notthere
$ echo $?
1
$ find . -maxdepth 1 -name notthere
$ echo $?
0
$ find . -failedarg
find: unknown predicate `-failedarg'
$ echo $?
1

Then, for a result where find had errors but found files:

$ ls -lh
$ d---------  2 jeff users   6 Feb  6 11:49 noentry
$ find .
.
./noentry
find: `./noentry': Permission denied
$ echo $?
1
$ find . | egrep '.*'
.
./noentry
find: `./noentry': Permission denied
$ echo $?
0
python ../test.py 
../test.py
$ echo $?
1

Then, if you want the list of files you can make use of -print 0 passed to find and split the out variable on nulls, or you can just add a print statement for it.

-1

It is not only find that returns the exit status codes as zero when it successful. In unix what ever the command you execute, if its succeeds then it returns the exit status as zero.

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