Hi Harry
I was about to try to explain it but sometimes a picture is worth a
thousand words (even if it's a picture of code:)
===========================================
22:35 ~/tmp $ cat bar.txt
this
is
a
very long test
22:35 ~/tmp $ cat foo.pl
#!/usr/bin/perl
use strict;
use warnings;
my $arg = $ARGV[0];
open(my $fh, '<', $arg);
{
#local $/;
my $i = 0;
while (my $foo = <$fh>) {
print "Line $i : $foo";
$i++;
}
}
22:35 ~/tmp $ ./foo.pl bar.txt
Line 0 : this
Line 1 : is
Line 2 : a
Line 3 : very long test
# Now, uncomment the call to local
22:36 ~/tmp $ ./foo.pl bar.txt
Line 0 : this
is
a
very long test
=========================================
If you want to change the newlines of that string into spaces, just
add this as the first statement inside the while:
$foo =~ s/\n/ /g;
Andrew
On Tue, Jan 20, 2015 at 10:10 PM, Harry Putnam <[email protected]> wrote:
> I found this little snippet in a post (from 2000) by Randal L. Schwartz:
>
> http://www.perlmonks.org/?node_id=20235
>
> The discussion was about:
>
> File::Slurp allows you read a filehandle into a scalar. However there
> is another way to do this without having to load an extra module at
> runtime. The select statement changes $/ (the input record separator)
> to a null character instead of a \n. And there you go..
>
> And a previous poster shows an example of doing it with `select';
>
> Randal responded:
>
> I just go:
>
> my $contents = do { local $/; <HANDLE> };
>
> The $/ variable is not per-filehandle, so no need to select.
>
> I have not been able to get this to work.
>
> My code uses the old style `open' just in case it would matter:
>
> use strict;
> use warnings;
>
> my $file = '.bashrc';
> open(FH, $file) or die "Can't open $file: $!";
> my $content = do { local $/; <FH> };
>
> print $content . "\n";
>
> But when I print `$content' my .bashrc file looks totally normal.
>
> I expected to see it as one long string.
>
> I also tried it with nothing in the script except(`use' stuff) and
> Randal's code slightly modified:
>
> use strict;
> use warnings;
>
> my $content = do { local $/; <> };
> print $content . "\n";
>
> Of course it changed nothing. The file was still printed with all
> newlines in place.
>
> Should I be seeing a file with no newlines being printed as a very
> long line?
>
>
> --
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>
--
Andrew Solomon
Mentor@Geekuni http://geekuni.com/
http://www.linkedin.com/in/asolomon
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