Re: Determine when file is done being written?

[Weasel]

trapping an error is easy:

eval {
  # your code to be trapped
  # ... or die "error message 123"
}
if ($@) {
  # do your error checking, such as $@=~/error message 123/
}

As was announced perl6 will change "eval{BLOCK}" to "try{BLOCK}" when it is used for trapping an error, to be more consistent.

It is interesting though to have a possibility to check whether writting is currently performing.

I think it is somewhere in IO::* modules (may be in IO::Handle), but unfortunately can not help with this right now.

Have a nice day,
Weasel.

[EyeOpener]

Thanks Weasel and everyone for the suggestions. The eval in a bare block turned out to be a nice, simple solution, and lets me catch more than just the possible error I know about:

sub dostuff {
    my $victim = shift;
    {
        eval {
            open IN, "$victim" or die "Can't open the file: $!\n";
        };
        last unless $@;
        if ($@ =~ /containing a running program/) {
            print "  Waiting...\n";
            sleep 5;
            redo;
        } else {
            die "Unknown error opening file: $@";
        }
    }
    # more stuff here
    close IN;
    rename "$victim", "/z/saved/$victim";
}

I'll have to get comfy with eval; I can see how it could be indispensable. Thanks again!

Peter

[Weasel]

Let me add little comment to save you from possible problem.

Actually eval("string") would be much slower than eval{BLOCK} because in first case Perl will parse it every time statement is executed, while second form will be compiled once, and actually it is a replacement for "try".

Best wishes,
Weasel.