Fwd: Is it a perl Bug?

[Nancy Clark]

Tom Franklyn <tomfranklyn@hotmail.com> wrote:From: "Tom Franklyn"
Subject: Is it a perl Bug?
Date: Wed, 04 Feb 2004 12:43:56 +0200

Dear all,

I've following code :

==========
#!/usr/bin/perl

my $a = "ab:cd:ef";
my @b = split(/:/,$a);
print ("@b\n");

my @c = ('/:/', $a);
my @d = split(@c);
print ("@d\n");
===========
Whats wrong with my code?
why @b and @d give different output?

Rgds,
Tom Franklyn
------------------------------------------------------------
Jesus?? Not a God!
[url]http://www.geocities.com/abdlfth99/jesus_not_a_god.htm[/url]




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[Gary Stainburn]

On Wednesday 04 February 2004 10:48 am, nancy clark wrote:

> Tom Franklyn <tomfranklyn@hotmail.com> wrote:From: "Tom Franklyn"
> Subject: Is it a perl Bug?
> Date: Wed, 04 Feb 2004 12:43:56 +0200
>
> Dear all,
>
> I've following code :
>
> ==========
> #!/usr/bin/perl
>
> my $a = "ab:cd:ef";
> my @b = split(/:/,$a);
> print ("@b\n");
>
> my @c = ('/:/', $a);
> my @d = split(@c);

What exactly are you wanting to happen here?

What you're actualy doing is calling

split(/ab/,'cd','ef');

which says use 'ab' as the pattern,'cd' as the expr, and 'ef' as the limit.

split obviously can't handle this and thus returns undef.

> print ("@d\n");
> ===========
> Whats wrong with my code?
> why @b and @d give different output?
>
> Rgds,
> Tom Franklyn
> ------------------------------------------------------------
> Jesus?? Not a God!
> [url]http://www.geocities.com/abdlfth99/jesus_not_a_god.htm[/url]
>
>
>
>
> ---------------------------------
> Do you Yahoo!?
> Yahoo! SiteBuilder - Free web site building tool. Try it!

--
Gary Stainburn

This email does not contain private or confidential material as it
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[Rob Dixon]

Nancy Clark wrote:

>
> Tom Franklyn <tomfranklyn@hotmail.com> wrote:From: "Tom Franklyn"
> Subject: Is it a perl Bug?
> Date: Wed, 04 Feb 2004 12:43:56 +0200
>
> Dear all,
>
> I've following code :
>
> ==========
> #!/usr/bin/perl
>
> my $a = "ab:cd:ef";
> my @b = split(/:/,$a);
> print ("@b\n");
>
> my @c = ('/:/', $a);
> my @d = split(@c);
> print ("@d\n");
> ===========
> Whats wrong with my code?
> why @b and @d give different output?

Hi Tom, Nancy.

Two problems here. First of all

my @c = ('/:/', $a)

should be either

my @c = (':', $a)
or
my @c = (qr/:/, $a)

otherwise the regex would match the three characters
slash, colon, slash.

Secondly, 'split' is prototyped, so it forces its first
parameter into scalar context. Array @c has two elements
so your call

my @d = split(@c)

is equivalent to

my @d = split(2)

which will try to split $_ on the regex '2'.

Look at this code:

$_ = "ab2cd2ef";
my @c = (1, 2);
my @d = split(@c);
print ("@d\n");

**OUTPUT

ab cd ef

HTH,

Rob