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

while (<$output>) {
  ...
}

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The code above doesn't work. But is there a bit of perl code that would allow me to easily iterate over the scalar, line by line, as if it were a file?

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Re: Equivalent code for input line operator on a scalar?
by broquaint (Abbot) on Feb 05, 2004 at 16:41 UTC
    Sure, see. IO::Scalar e.g 
    use IO::Scalar;

my $output = <<TXT;
this is the first line
and this is the second line
but this is the last
TXT

my $scalar_fh = IO::Scalar->new(\$output);

print while <$scalar_fh>;

__output__

this is the first line
and this is the second line
but this is the last

    [download]
    HTH

    _________
    broquaint

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Re: Equivalent code for input line operator on a scalar?
by Zaxo (Archbishop) on Feb 05, 2004 at 16:43 UTC

    In perl 5.8 you can open a scalar as if it were a file, by giving a reference to the scalar in the filename slot, 

    open my $fh, '<', \$output or die $!;
while (<$fh>) {
    #...
}
close $fh or die $!;

    [download]
    In earlier perl IO::Stringy or IO::Scalar are needed, but their treatment of $/ leaves something to be desired.

    After Compline,
    Zaxo

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Re: Equivalent code for input line operator on a scalar?
by Abigail-II (Bishop) on Feb 05, 2004 at 16:58 UTC 
    $output = "...............";
while (local ($_) = $output =~ /(.*\n?)/) {
    ...
}

    [download]

    This is assuming you haven't modified $/ (or $*).

    Abigail

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[d/l]
      Need a /g on there.
      The PerlMonk tr/// Advocate
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[d/l]
Re: Equivalent code for input line operator on a scalar?
by Roy Johnson (Monsignor) on Feb 05, 2004 at 17:14 UTC
    See this Q&A.
    The PerlMonk tr/// Advocate
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Re: Equivalent code for input line operator on a scalar?
by Plankton (Vicar) on Feb 05, 2004 at 16:47 UTC
    But is there a bit of perl code that would allow me to easily iterate over the scalar, line by line, as if it were a file?

    Why would you want to do that? Besides you don't iterate over a file. You iterate over lists (or arrays). So you want to turn your scalar into an array with something like this ... 
    my $scalar_var = "1|2|3|4|5";
my @list = split /\|/, $scalar_var;
while( pop(@list) ) {
   ...
}

    [download]

    Plankton: 1% Evil, 99% Hot Gas.
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[d/l]
Re: Equivalent code for input line operator on a scalar?
by Old_Gray_Bear (Bishop) on Feb 05, 2004 at 16:48 UTC
    If I understand corrently, you want to look at the FileHandle module. 
    $fh = FileHandle::new('File Name','mode');
$fn -> open('mode');
while($fh->getline()) {

#stuff goes here

}

$fh -> close();

    [download]

    (Untested, and Bear-ly proof read.)

    ----
    I Go Back to Sleep, Now.

    OGB

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[d/l]

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