On Dec 31, 2007 5:56 PM, Jean-Rene David <[EMAIL PROTECTED]> wrote:
> Hi,
>
> I wonder what idioms are available to loop through
> the lines stored in a scalar variable. I guess I'm
> looking for something analogous to these idioms
> for files and arrays respectively:
>
> while(<FH>) {
> # do stuff
> }
>
> foreach (@array) {
> # do stuff
> }
>
> When I had to do this I split the scalar in an
> array:
>
> @array = split "\n", $scalar;
> foreach (@array) {
> # do stuff
> }
snip
I would say the most common way would be to use the list returned by
split in the for directly:
#!/usr/bin/perl
use strict;
use warnings;
my $s = "foo\nbar\nbaz\nquux\n";
my $i;
for my $line (split "\n", $s) {
print $i++, " $line\n";
}
But you could also use a regex with the g and m modifiers in scalar
context if you were worried about space issues (e.g. the scalar holds
a gigabyte of data you don't want to duplicate)
#!/usr/bin/perl
use strict;
use warnings;
my $s = "foo\nbar\nbaz\nquux\n";
my $i;
while ($s =~ /^(.*)$/gm) {
my $line = $1;
print $i++, " $line\n";
}
Also, it is a good idea to use the strict and warnings pragmas (like I
did in the code above) and to use named variables in your for loops.
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