“find” exclude by fstype strange behavior

filesystemsfindproc

I try to have "find" command exclude "/proc" filesystem.
I would prefer a portable solution to be able to use it on non GNU based hosts (oldest AIX for instance, where "find" do not have the "-path" option)

Here's what I've tried (on a Linux host) and a partial filtered output:

$  find /  ! -fstype proc   >/dev/null
find: `/proc/9475/task/9535/fdinfo/7': No such file or directory
find: `/proc/10856': No such file or directory
find: `/proc/10856': No such file or directory
find: `/proc/10858': No such file or directory
find: `/proc/10858': No such file or directory
find: `/proc/15650': No such file or directory
find: `/proc/15650': No such file or directory
find: `/proc/15654': No such file or directory
find: `/proc/15654': No such file or directory
find: `/proc/15656': No such file or directory
find: `/proc/15656': No such file or directory
find: `/proc/15657': No such file or directory
find: `/proc/15657': No such file or directory
find: `/proc/15663': No such file or directory
etc ....

I don't understand why "find" keep walking inside the "/proc" file system despite of the "! -fstype proc" switch?

Best Answer

As terdon explained, find will still enter the /proc directory, but it will not return any pathnames from that filesystem type.

To remove any search path as soon as the proc filesystem type is detected, use

find / -fstype proc -prune -o -print

However, since you're wanting to do this on an old find, the -fstype option may not be available. If -path (a standard option of find) is also not available, then it begins to be a bit difficult to come with suggestions as the implementation is clearly not POSIX compliant.

One option could be to use -xdev which would cause find to stay strictly in the same filesystem as the starting path. You would then have to run one find for each filesystem that you want to examine. There could also be an option called -x (as on BSD systems) which acts like -xdev.

If that too is not possible, then you may have to resort to using -type d -name proc -prune to disregard all directories that are called proc.

Related Solutions

Find – How to Exclude Directory

On the research for a similar find solution I discovered the helpful explanation on How to use '-prune' option of 'find' in sh? by Laurence Gonsalves.

You could use something like:

find . \( -type d -name .hg -prune \) -o \( -type f -name "foo" -print \)

or (without the name)

find . \( -type d -name .hg -prune \) -o \( -type f -print \)

The (escaped) parentheses \( and \) group the tests (type and name) and corresponding actions (prune and print, respectively) together left and right of the OR (-o).

Since -o has lower precedence than juxtaposition, you can omit the parentheses if you like. Many find implementations also let you skip the final -print.

find . -type d -name .hg -prune -o -type f -name "foo" -print

Exclude directory in find

find . -name 'foo-exclude-me' -prune -o -name 'foo*' -print

With no -print, the implicit default action applies to every match, even pruned ones. The explicit -print applies only under the specified conditions, which are -name 'foo*' only in the else branch of -name 'foo-exclude-me'.

Generally speaking, use an explicit -print whenever you're doing something more complex than a conjunction of predicates.

Your second attempt with ! -path './foo-exclude-me/*' didn't work because ./foo-exclude-me doesn't match ./foo-exclude-me/* (no trailing /). Adding ! -path ./foo-exclude-me would work.

Best Answer

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Find – How to Exclude Directory

Exclude directory in find

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