Re^2: Unlinking a file when the file doesnt exist

Unfortunately, $! is garbage in that example. It would only be meaningful if stat (via -e) failed. One definitely cannot count on it having any info about an unlink error.

I recommend

for my $file (qw(files.txt data.txt)) {
    unlink($file)
        or $!{ENOENT}
        or die("Unable to unlink '$file': $!");
}
[download]

Or if one wants to clean up as many files as possible even if some can't be deleted,

my $success = 1;
for my $file (qw(files.txt data.txt)) {
    if (!unlink($file) && !$!{ENOENT}) {
        warn("Unable to unlink '$file': $!");
        $success = 0;
    }
}

die("Unable to cleanup") if !$success;
[download]

Comment on Re^2: Unlinking a file when the file doesnt exist Select or Download Code

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Re^3: Unlinking a file when the file doesnt exist by moritz (Cardinal) on Mar 22, 2011 at 21:19 UTC
Unfortunately, $! is garbage in that example. It contained the right value when I tried it. Is that platform (or perl version) dependent? Perl 6 - second systems done right	[reply]
Re^4: Unlinking a file when the file doesnt exist by ikegami (Patriarch) on Mar 22, 2011 at 21:31 UTC
It may have the right value if you're lucky. `stat` is free to change it, and you can reach the `die` even if `unlink` was successful.	[reply] [d/l] [select]
Re^3: Unlinking a file when the file doesnt exist by Gulliver (Monk) on Mar 23, 2011 at 15:12 UTC
Unfortunately, $! is garbage in that example. From unlink: Deletes a list of files. On success, it returns the number of files it successfully deleted. On failure, it returns false and sets $! (errno): One of the examples at the perldoc page for unlink shows using $! with warn() in a foreach loop. Why shouldn't $! be used in this case?	[reply]
Re^4: Unlinking a file when the file doesnt exist by ikegami (Patriarch) on Mar 23, 2011 at 15:47 UTC
I didn't say anything that contradicts that. It's perfectly fine to use `$!` immediately after `unlink` returns an error as I showed in the very post you quoted. In moritz's code, `$!` isn't being used immediately after `unlink` returns an error. In decreasing likeliness of occurrence, It's sometimes used after `stat` (`-e`) successfully returns false. (Can change `$!`.) It's sometimes used after `stat` (`-e`) returns an error. (Always sets `$!`.) It's sometimes used after `unlink` returns success. (!!!)	[reply] [d/l] [select]