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

Hi -- I'm looking for a routine to encapsulate slurp. If no filename is given, I'd like to slurp STDIN. The code below doesn't work in this case; can someone point out why? Thanks! rkg 
use strict;
use FileHandle;

sub slurp {
    my $fh = new FileHandle;
    my $file = 'STDIN';
    $file = $_[0] if $_[0];
    $fh->open($file) or die "Can't open $file: $!";
    $fh->input_record_separator(undef);
    my $slurp = <$fh>;
    $fh->close or die "Can't close $file: $!";
    $slurp;
}

print slurp();

[download]

Replies are listed 'Best First'.
Re: STDIN question
by castaway (Parson) on Jun 19, 2003 at 14:13 UTC
    There are modules which do this: File::Slurp for example..

    C.

[reply]
      And how do I reference STDIN for File::Slurp? Sorry to be slow on this...rkg
[reply]

        ++hmerrill 

        # test2.pl
use File::Slurp;

$all_of_it = read_file('-');
print $all_of_it;
__END__
$ >echo -e "klöhlkhklhj\nlkjhlkhlkhkk\nlkjhklhlkhklh" | perl test2.pl
klöhlkhklhj
lkjhlkhlkhkk
lkjhklhlkhklh

        [download]

        regards,
        tomte

        Hlade's Law:

        If you have a difficult task, give it to a lazy person --
        they will find an easier way to do it.

[reply]
[d/l]
Re: STDIN question
by hmerrill (Friar) on Jun 19, 2003 at 14:19 UTC
    I'm taking a wild shot-in-the-dark here, but according to 'perldoc -f open': 
           open FILEHANDLE,EXPR
       open FILEHANDLE,MODE,EXPR
       open FILEHANDLE,MODE,EXPR,LIST
       open FILEHANDLE,MODE,REFERENCE
       open FILEHANDLE

       <snip>

       In the 2-arguments (and 1-argument) form opening
       ’-’ opens STDIN and opening ’>-’ opens STDOUT.

    [download]
    So, I'm wondering if changing your 
        my $file = 'STDIN';
        to
    my $file = '-';

    [download]
    would work???

    HTH.
[reply]
[d/l]
[select]
Re: STDIN question
by ant9000 (Monk) on Jun 19, 2003 at 15:19 UTC
    You can use typeglobs:
    use strict;

print myslurp();

sub myslurp {
 if(shift){
  open(F,"<$_") or die "Can't open $_: $!";
 }else{
  F=*STDIN{IO};
 }
 local $/=undef;
 my $slurp=<F>;
 close(F);
 $slurp;
}

    [download]
[reply]
[d/l]
Re: STDIN question
by mod_alex (Beadle) on Jun 19, 2003 at 15:43 UTC
    Hello First, please, read about file handling in perl and
    think after what $file='STDIN' means.
    check this version of your method 
    #! /usr/bin/perl

use strict;
use warnings;

use strict;
use FileHandle;

sub slurp {
    my $fh = new FileHandle;
    my $file = shift;
    local undef($/);
    if (defined($file)) {
      $fh->open($file) or die "Can't open $file: $!";
    } else {
      $fh->fdopen(*STDIN, 'r');
    }
    my $slurp = <$fh>;
    $fh->close or die "Can't close $file: $!";
    $slurp;
}

print slurp();

    [download]
    Alex
[reply]
[d/l]

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