Supressing 'Permission Denied' warning in du command

Question

I want to list the size of all sub-folders in a directory. when I try du -h --max-depth=1 the output is cluttered with 'Permission denied' statements as such

du: cannot read directory `./folder_name': Permission denied

How can I suppress these warnings?

I tried a workaround by piping the the output to grep as follows

du -h --max-depth=1 | grep -v 'du:'

but that does not seem to be working either!

score 5 · Accepted Answer · answered Feb 06 '16 at 18:09

5

Try:

$ du -h --max-depth=1 2>/dev/null

This redirects stderr (file handle 2) to /dev/null, ignoring any error messages.

answered Feb 06 '16 at 18:09

e0k

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Is there a reason why `grep -v` doesn't work? – sandy Feb 06 '16 at 18:17
1

The reason your `grep -v 'du:'` doesn't work is because the error messages are on the stderr stream. In a pipe such as the one shown it's the stdout stream which is redirected from one command to the next, and thus the `grep` command never sees the error messages. – Bob Jarvis - Слава Україні Feb 06 '16 at 18:18
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@sandy: Recommended reading: [Standard streams](https://en.wikipedia.org/wiki/Standard_streams) – Cyrus Feb 06 '16 at 18:20
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Note that you could *make* the grep command work by redirecting `du`'s stderr stream to stdout. Try `du -h --max-depth=1 2>&1 | grep -v 'du:'`. Best of luck. – Bob Jarvis - Слава Україні Feb 06 '16 at 18:25

Supressing 'Permission Denied' warning in du command

1 Answers1