unlink $file OR... OR..

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

Sorry if this is so trivial but I've never done something like this and I'm sure it's easy.

I'm unlinking a file and need to print to the screen AND push(@list, $file) if it fails all in one go.

I don't suppose something like this would be the best way? It's untested but I'm sure it works but still, I don't really care to use a sub for this.

unlink $file or &oopsies($file);

sub oopsies
{
   print "Error!";
   push(@list, shift); #<-- heck, I've never tried using SHIFT like th
+is- so intriguing I'm going to test that.
}
[download]

Comment on unlink $file OR... OR.. Download Code

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Re: unlink $file OR... OR.. by GrandFather (Saint) on Aug 30, 2007 at 03:49 UTC
Why not: `unless (unlink $file) { print "..."; push @list, $file; }` [download] which at least avoids using a global array in the sub. If you need to do it a lot put the unlink into a sub: `DoDaUnlink ($file, \@list); sub DoDaUnlink { my ($file, $list) = @_; return if unlink $file; print "..."; push @$list, $file; }` [download] DWIM is Perl's answer to Gödel	[reply] [d/l] [select]
Re: unlink $file OR... OR.. by bobf (Monsignor) on Aug 30, 2007 at 03:45 UTC
Perhaps a do block would suffice? `unlink $file or do { print "Error!"; push( @list, $file ); };` [download] You could accomplish this using a series of `and` (or `&&`, see perlop) and parentheses, but IMO the do block is more clear.	[reply] [d/l] [select]
Re: unlink $file OR... OR.. by sulfericacid (Deacon) on Aug 30, 2007 at 03:43 UTC
Aye, you can use shift as though it's a variable. I do many a print shift;. It saves on typing and stress of coming up with yet ANOTHER unique variable name. UPDATE: Adding code for the original question `#!/usr/bin/perl use warnings; use strict; my @list; push(@list, "blah.txt"), print qq(Error\n) unless unlink "blah.txt"; print @list;` [download] "Age is nothing more than an inaccurate number bestowed upon us at birth as just another means for others to judge and classify us" sulfericacid	[reply] [d/l]
Re: unlink $file OR... OR.. by kyle (Abbot) on Aug 30, 2007 at 03:50 UTC
What's wrong with using a sub? If you really don't want to, make it a block: `if ( ! unlink $file ) { warn "Can't unlink '$file': $!\n"; push @unlink_failures, $file; }` [download] If you want it shorter, maybe: `@unlink_failures = grep { ! unlink } @files_to_unlink; warn "unlink failed for '$_'\n" for @unlink_failures;` [download] I guess that could be all one line (though I haven't tried this) this way: `warn "unlink failed for '$_'\n" for ( @unlink_failures = grep { ! unlink } @files_to_unlink );` [download] ...but that's getting pretty convoluted (and it loses the error messages from `$!`). I recommend the block.	[reply] [d/l] [select]
Re: unlink $file OR... OR.. by Prof Vince (Friar) on Aug 30, 2007 at 13:58 UTC
For the sake of completeness, you can also use an anonymous sub : `unlink $file or sub { print 'Error!'; push @list, $file; }->();` [download] Using unless or a do block would be the preferred way though. Also, don't call subs with & unless you've read perlsub and you've understood what it does.	[reply] [d/l]


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