regex grouping

jfroebe has asked for the wisdom of the Perl Monks concerning the following question:

Hi,

I have a string that I'm trying to group the items so that I'm able to use @$0 to retrieve N number of items for use elsewhere.

1 2=3 4=5
1 2=3 and 4=5
[download]

I could just put a delimiter between the groups and use split on the modified string, but I would like it as a single regex - if that is possible.

% perl -e '$str = "1 2=3 4=5"; print "$str\n"; $str =~ s/(\w+[\w\s]*=\
+w+)(?:\s)*/$1\|/g; print "$str\n"; print "Should look like: 1 2=3|4=5
+|\n"'

1 2=3 4=5
1 2=3|4=5|
Should look like: 1 2=3|4=5|
[download]

Something like so. (note: nonworking code)

perl -e '$str = "1 2=3 4=5"; print "$str\n"; $str =~ m/(\w+[\w\s]*=\w+
+)(?:\s)*/g; print "$_\n" foreach @$0;'
1 2=3 4=5

1 2=3
4=5
[download]

UPDATE: The number of items is variable. i.e. "1 2 3 2 6=7 2=4 j=384923 34 43 j 3=6". Given that string I would need grouping like so:

1 2 3 2 6=7
2=4
j=384923
34 43 j 3=6
[download]

Here is the code that works:

perl -e '$str = "1 2 3 2 6=7  2=4 j=384923 34 43 j 3=6"; print "$_\n" 
+foreach ($str =~ m/(\w+[\w\s]*=\w+)/g);'

1 2 3 2 6=7
2=4
j=384923
34 43 j 3=6
[download]

Jason L. Froebe

Team Sybase member

No one has seen what you have seen, and until that happens, we're all going to think that you're nuts. - Jack O'Neil, Stargate SG-1

Comment on regex grouping Select or Download Code

Replies are listed 'Best First'.
Re: regex grouping by Roy Johnson (Monsignor) on Nov 02, 2005 at 18:31 UTC
Something like this? `$_ = '1 2=3 4=5'; for my $up_to_3 (/(?:\W\w+){1,3}/g) { print $up_to_3, "\n"; }` [download] Update: oh, you want each grouping to start with a \w, and end with an equal sign and the number following it. `$_ = '1 2 3 2 6=7 2=4 j=384923 34 43 j 3=6'; for my $foo (/(?:\w[^=]=\w+)/g) { print $foo, "\n"; }` [download] Caution: Contents may have been coded under pressure.	[reply] [d/l] [select]
Re^2: regex grouping by jfroebe (Parson) on Nov 02, 2005 at 19:12 UTC
thanks! I've modified the original script to reflect your for loop :) Jason L. Froebe Team Sybase member No one has seen what you have seen, and until that happens, we're all going to think that you're nuts. - Jack O'Neil, Stargate SG-1	[reply]
Re: regex grouping by GrandFather (Saint) on Nov 02, 2005 at 18:35 UTC
This would seem to be what you want: `use strict; use warnings; my $str = "1 2=3 4=5"; print "$str\n"; my @strs = $str =~ m/(\w+=\w+)/g; print "$_\n" foreach @strs;` [download] Prints: `1 2=3 4=5 2=3 4=5` [download] Perl is Huffman encoded by design.	[reply] [d/l] [select]