Re: [Question] Reliable way to clean up a directory in EXIT trap

[Masahiro Yamada]

On Tue, Jul 19, 2022 at 4:23 PM Alex fxmbsw7 Ratchev <fxmbsw7@gmail.com> wrote:
>
>
>
> On Tue, Jul 19, 2022, 03:19 Masahiro Yamada <masahiroy@kernel.org> wrote:
>>
>> On Tue, Jul 19, 2022 at 2:47 AM Greg Wooledge <greg@wooledge.org> wrote:
>> >
>> > On Tue, Jul 19, 2022 at 02:15:38AM +0900, Masahiro Yamada wrote:
>> > > #!/bin/bash
>> > > set -e
>> > >
>> > > # use .tmp_<PID> as a temporary workspace
>> > > TMPDIR=.tmp_$$
>> > >
>> > > trap "rm -rf $TMPDIR" EXIT
>> > >
>> > > mkdir -p $TMPDIR
>> > > touch $TMPDIR/tmp
>> >
>> > The first problem I see with this is that you've used a *relative*
>> > pathname for your TMPDIR variable.  The trap is going to issue a command
>> > of the form "rm -rf .tmp_12345" when your script exits.
>> >
>> > What happens if, later on, you modify this script to change directory
>> > somewhere?  If the trap runs after the script has changed directory,
>> > you might be removing that relative pathname from the wrong place.
>> >
>> > The second problem is lack of proper quoting -- not going to bite you
>> > right now, because you've restricted your TMPDIR variable to a known
>> > value that doesn't contain whitespace or globbing characters, but proper
>> > quoting is a good habit to develop.  In the future, you'll be using
>> > variables whose contents are *not* safe when used without proper quoting.
>> >
>>
>>
>> Thanks for the advice, but what you pointed out
>> does not affect the issue I am facing.
>
>
> .. maybe, first set tmpvar, then first create it, then just set the trap..
> creation prior to cleanup


I also tried that.
The .tmp directory is left-over



If we create the directory before the trap,
what if we are interrupted between them?


mkdir -p $TMPDIR
#   <--If we are interrupted here,  there is no-one that cleans up the tmp dir?
trap "rm -rf $TMPDIR" EXIT







-- 
Best Regards
Masahiro Yamada