Regular Expression in Perl

tarken · 05-12-2010, 03:30 PM

I am trying to create a regular expression in perl to remove all the delimiters (|) from a file. I was also thinking might I be able to use tr?

Tarken

AlucardZero · 05-12-2010, 03:40 PM

Feel free.

Did you have a question? What have you got already?

MTK358 · 05-12-2010, 04:28 PM

Code:

sed 's/|//g'

tarken · 05-12-2010, 04:41 PM

Code:

system(`tr -d "|" <temp.1 > temp.2 &`);

I figured it out. This works fine. Any reason I should not be sending the commands out to the shell?

Tarken

Sergei Steshenko · 05-12-2010, 04:57 PM

Quote:

Originally Posted by tarken

Code:

system(`tr -d "|" <temp.1 > temp.2 &`);

I figured it out. This works fine. Any reason I should not be sending the commands out to the shell?

Tarken

And Perl has nothing to do with this - you do all the job in shell using 'tr'. And you do not need backtticks as well.

tarken · 05-12-2010, 05:20 PM

Quote:

Originally Posted by Sergei Steshenko

And Perl has nothing to do with this - you do all the job in shell using 'tr'. And you do not need backtticks as well.

The reason I am writing this in Perl because it will be part of other existing code that is written in Perl.

patolfo · 05-12-2010, 05:28 PM

you might use a shell wrapper, more fancy. And do all the shell processing you need, and then going back to perl with the final data.
Well if you only need to change |, why not:
$string=~ s/\|//g;
Assuming $string contains a text line of the file

Sergei Steshenko · 05-12-2010, 06:16 PM

Quote:

Originally Posted by tarken

The reason I am writing this in Perl because it will be part of other existing code that is written in Perl.

Which doesn't disprove what I've said - your solution has nothing to do with Perl. A solution in Perl would use Perl regular expressions or Perl built-in 'tr' or 'y' function.

MTK358 · 05-12-2010, 07:11 PM

Quote:

Originally Posted by patolfo

$string=~ s/\|//g;
Assuming $string contains a text line of the file

That's what I was thinking and wanted to suggest — I just forgot the exact Perl s/// syntax.

smeezekitty · 05-12-2010, 07:38 PM

Quote:

Originally Posted by MTK358

That's what I was thinking and wanted to suggest — I just forgot the exact Perl s/// syntax.

Its basically =~ <sed syntax here>.

MTK358 · 05-12-2010, 07:58 PM

sed can do far more than s///.

smeezekitty · 05-12-2010, 08:10 PM

^ but thats what its most used for.
On a second note, so can perl.