Re: Use of `mktemp' is dangerous, better use `mkstemp'...

[Ángel]

On 2021-01-15 at 10:00 -0500, Chet Ramey wrote:
> On 1/14/21 11:45 PM, Jeffrey Walton wrote:
> > Hi Everyone,
> > 
> > I'm building Bash 5.1 from sources. This may be of interest:
> > 
> > /usr/bin/ld: ./lib/sh/libsh.a(tmpfile.o): in function
> > `sh_mktmpname':
> > /home/jwalton/Build-Scripts/bash-5.1/lib/sh/tmpfile.c:160: warning:
> > the use of `mktemp' is dangerous, better use `mkstemp' or `mkdtemp'
> 
> It's a spurious warning.

mktemp() would only end up being used (with all its issues) if the OS
doesn't provide a DEV FD or there's no mkdtemp(). In other (safe)
Operating Systems, it would be possible to avoid the warning by
building a slightly different libsh.a in such case.

I have made a quick patch (see attachment) and it does work.
My system would normally report that warning. My compiler is smart
enough to ellide mktemp with this change. bash tests pass after the
change, both with dev-fs and disabling it (with only run-procsub
failing, but that's expected).

Best regards

skip_mktemp.patch
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