Perl中没有提供文件名时如何使用__DATA__句柄

Question

Looking for a way using the DATA handle if no filename provided to the perl script.

I'm not very skilled in perl.

Something like:

use strict;
use warnings;
use autodie;
use diagnostics;

my $fd;
if( $ARGV[0] && -f $ARGV[0] ) {
    open $fd, "<", $ARGV[0];
} else {
    $fd = "DATA";   #what here?
}

process($fd);
close($fd); #closing the file - or the DATA handle too?

sub process {
    my $handle = shift;
    while(<$handle>) {
        chomp;
        print $_,"\n";
    }
}

__DATA__
default content

Answer 1

$fd=\\*DATA ; should do the trick

Answer 2

You may prefer to default to the DATA handle if the file open fails instead of letting autodie stop your program. That is a better test anyway than -f . Something like this perhaps

my $fd = \*DATA;
if (@ARGV) {
  if (open $_, '<', $ARGV[0]) {
    $fd = $_;
  }
  else {
    warn qq{Unable to open "$ARGV[0]" for reading: $!};
  }
}