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Programming Perl, 3rd Edition
book

Programming Perl, 3rd Edition

by Larry Wall, Tom Christiansen, Jon Orwant
July 2000
Intermediate to advanced content levelIntermediate to advanced
1104 pages
35h 1m
English
O'Reilly Media, Inc.
Content preview from Programming Perl, 3rd Edition

Errno

use Errno;
unless (open(FH, $pathname)) {
    if ($!{ENOENT}) {  # We don't need an import for this!
        warn "$pathname does not exist\n";
    }
    else {
        warn "open failed on `$pathname': $!";
    }
}

use Errno qw(EINTR EIO :POSIX);
if ($! == ENOENT) { …. }

The Errno module makes available the symbolic names for the error status values set when a syscall fails, but does not export them by default. The module has a single export tag, ":POSIX", which exports only those symbols defined by the POSIX 1003.1 standard. The module also makes the global %! variable magical using tie. You can subscript into the %! hash using any valid errno on your system, not just the POSIX ones, and its value is true only if that's the current error.

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Publisher Resources

ISBN: 0596000278Supplemental ContentErrata