[OT] how to use a constant in regex?

[Warren Pollans]

Hi Folks,

This is not OSX-related, but I'm hoping that some OSXer could point 
me in the right direction.  This has to have a RTFM answer but I 
haven't been able to find the FM to R.

I can't figure out how to use a constant in a regular expression 
without having to assign it to a variable first.  Here's what I mean:

#!/usr/bin/perl -w

use strict;
use constant FS = '##';

my $x = 'sadfjsfh##fskdjfa;s##dfjhasfjh';

my $y = FS;
$x =~ s/FS/ZZ/g;
print 1:$x\n;
$x =~ s/FS()/ZZ/g;
print 2:$x\n;
$x =~ s/$y/ZZ/g;
print 3:$x\n;
print FS,\n;
print FS(),\n;


Output is:

1:sadfjsfh##fskdjfa;s##dfjhasfjh
2:sadfjsfh##fskdjfa;s##dfjhasfjh
3:sadfjsfhZZfskdjfa;sZZdfjhasfjh
##
##


Thanks,

Warren

Re: [OT] how to use a constant in regex?

[Bruce Van Allen]

At 1:20 PM -0400 2002-08-30, Warren Pollans wrote:
Hi Folks,

This is not OSX-related, but I'm hoping that some OSXer could point 
me in the right direction.  This has to have a RTFM answer but I 
haven't been able to find the FM to R.

With Perl, there is always its own internal documentation, in this 
case the POD of constant.pm.

However, :-), a quick scan didn't confirm that this was where I 
learned the answer to your question, which is to de-reference a 
reference to the constant (!!).

#!/usr/bin/perl -w
use strict;
use constant FS = '##';

my $x = 'sadfjsfh##fskdjfa;s##dfjhasfjh';

$x =~ s/${ \FS }/ZZ/g;  # or ${ \FS() }
#   ^^ ^   ^
print 1:$x\n;

__END__

I can't figure out how to use a constant in a regular expression 
without having to assign it to a variable first.  Here's what I mean:

#!/usr/bin/perl -w

use strict;
use constant FS = '##';

my $x = 'sadfjsfh##fskdjfa;s##dfjhasfjh';

my $y = FS;
$x =~ s/FS/ZZ/g;
print 1:$x\n;
$x =~ s/FS()/ZZ/g;
print 2:$x\n;
$x =~ s/$y/ZZ/g;
print 3:$x\n;
print FS,\n;
print FS(),\n;


Output is:

1:sadfjsfh##fskdjfa;s##dfjhasfjh
2:sadfjsfh##fskdjfa;s##dfjhasfjh
3:sadfjsfhZZfskdjfa;sZZdfjhasfjh
##
##


Thanks,

Warren

-- 

   - Bruce

__bruce_van_allen__santa_cruz_ca__

Re: [OT] how to use a constant in regex?

[Warren Pollans]

Thanks, that did it

At 1:20 PM -0400 2002-08-30, Warren Pollans wrote:
Hi Folks,

This is not OSX-related, but I'm hoping that some OSXer could point 
me in the right direction.  This has to have a RTFM answer but I 
haven't been able to find the FM to R.

With Perl, there is always its own internal documentation, in this 
case the POD of constant.pm.

However, :-), a quick scan didn't confirm that this was where I 
learned the answer to your question, which is to de-reference a 
reference to the constant (!!).

#!/usr/bin/perl -w
use strict;
use constant FS = '##';

my $x = 'sadfjsfh##fskdjfa;s##dfjhasfjh';

$x =~ s/${ \FS }/ZZ/g;  # or ${ \FS() }
#   ^^ ^   ^
print 1:$x\n;

__END__

I can't figure out how to use a constant in a regular expression 
without having to assign it to a variable first.  Here's what I 
mean:

#!/usr/bin/perl -w

use strict;
use constant FS = '##';

my $x = 'sadfjsfh##fskdjfa;s##dfjhasfjh';

my $y = FS;
$x =~ s/FS/ZZ/g;
print 1:$x\n;
$x =~ s/FS()/ZZ/g;
print 2:$x\n;
$x =~ s/$y/ZZ/g;
print 3:$x\n;
print FS,\n;
print FS(),\n;


Output is:

1:sadfjsfh##fskdjfa;s##dfjhasfjh
2:sadfjsfh##fskdjfa;s##dfjhasfjh
3:sadfjsfhZZfskdjfa;sZZdfjhasfjh
##
##


Thanks,

Warren

--

   - Bruce

__bruce_van_allen__santa_cruz_ca__