Re: [gentoo-user] xargs and rm funkiness

[Etaoin Shrdlu]

On Saturday 29 May 2010, Daniel D Jones wrote:
> On Wednesday 26 May 2010 06:42:08 Joerg Schilling wrote:
> > Patrick Holthaus <patrick.holthaus@×××××××××××××.de> wrote:
> > > You might try:
> > >
> > > find -name *.ext -print0 | xargs -0 rm
> >
> > But this is non-standard.
>
> In what way is this non-standard?  That is, what standard is it contrary
>  to?

SUS (aka POSIX), although some people are pushing to include -print0 | xargs 
-0 into the standard. What Joerg meant is that the above construct will only 
run when using GNU find and xargs. Of course, if you're running Linux, that is 
probably the case already anyway.

>  TMTOWTDI (There's More Than One Way To Do It) applies just as strongly
>  to *nix in general as it does to Perl.  When there are multiple ways to do
>  something, it's often either a user preference issue or the method should
>  be decided based upon the particular details of the desired result.  -exec
>  may be a POSIX standard function, but that doesn't mean it must be used
>  over other options or you're breaking the standard.
>
> > UNIX introduced -exec {} + 1990 (when David Korn rewrote find(1)
> > and it is in the POSIX standared since some time.
>
> -exec (which potentially has problems with race conditions - -execdir
>  should almost always be used instead) runs the command once for each file
>  found.

If you use -exec {} + as he wrote, this is not true.

>  xargs will call the command once for as many files as it can fit on
>  the command line.

And so does -exec {} +

>  For some instances, like rm, that probably isn't
>  significant.  But if you're calling a complex process with lots of files,
>  the overhead of starting the many extra processes may be significant.

See above.