Regex problem

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

Hi, I need a regex to match and split lines of the form

............ keyword=nn ............
[download]

where ..'s represent variable numbers of any char.

I would like $1 to be anything upto and including the =

$2 to be nn (can be 1 2 or 3 decimal digits)

$3 to be everything including the space(s) to the end of the line.

I thought this would do it

while(<>) {
  m/^(.+?\s+keyword=)(\d+)(\s+.+)$/
  print "$1-" if $1;
  print "$2-" if $2;
  print "$3" if $3;
  print "\n";
}
[download]

But I get nothing?

Comment on Regex problem Select or Download Code

Replies are listed 'Best First'.
Re: Regex problem by Abigail-II (Bishop) on Jul 04, 2002 at 15:12 UTC
Well, the code you have there doesn't even compile (it's missing a semi colon). So, you didn't cut and paste it. What's your real code you have a problem with? (No, this is not an invitation to cut and paste a gazillion lines of code - write a short program that doesn't do what you expect it to do, test it, and cut and paste that). If I add the semi colon, I do get the expected output. Giving `............ keyword=13 ............` [download] as input produces `............ keyword=-13- ............` [download] as output. Perhaps your input doesn't contain what you expect it to contain. Abigail	[reply] [d/l] [select]
Re: Re: Regex problem by Anonymous Monk on Jul 04, 2002 at 16:16 UTC
Thanks Abigail & Kurt for saving my sanity. The missing semi-colon was a typo:( The problem, once I had stopped focusing on the regex was a line at the top of the loop that did `next if m/keyword/;` [download] I some how deleted the ! from in front of the m//? It was there earlier....grrrr.	[reply] [d/l]
Re: Re: Re: Regex problem by amphiplex (Monk) on Jul 04, 2002 at 18:13 UTC
just a sidenote: this additional check will not increase the performance of your script but actually slow it down. ---- kurt	[reply]
Re: Regex problem by amphiplex (Monk) on Jul 04, 2002 at 15:13 UTC
your script worked for me, did you maybe test with "keyword=nn" instead of for example "keyword=12" ? This will not work of course, as you are matching digits after the "=". And you forgot the ";" in the line with the regex, but I think this was only a typo. ---- kurt	[reply]
Re: Regex problem by vladb (Vicar) on Jul 04, 2002 at 15:15 UTC
What input are you trying? If indeed you've tried this string: `............ keyword=nn ............` [download] Then the regexp you've used won't work. It'll brake right after the 'keyword=' part as 'nn' string doesn't match '\d+' expression. However, this works: `while(<DATA>) { m/^(.+?\s+keyword=)(\d+)(\s+.+)$/; print "$1-" if $1; print "$2-" if $2; print "$3" if $3; print "\n"; } __DATA__ ............ keyword=12 ............` [download] _____________________ `# Under Construction` [download]	[reply] [d/l] [select]
Re: Regex problem by DamnDirtyApe (Curate) on Jul 04, 2002 at 15:14 UTC
I'm not sure if the leading ..'s in your example are supposed to be part of the keyword or not. If not, as your example shows, try this: `#! /usr/bin/perl use strict ; use warnings ; my @str = ( 'fdjsflsdfjk foo=123 sdjflsdfjklsfj ', 'sdfhsdfsd bar=42 fkjfjklsfjs', 'zoot=23 ff ', ' nooka=9 ' ) ; foreach (@str) { /([[:alnum:]]+)=([[:digit:]]{1,3})(.)$/ ; printf "[%s] [%s] [%s]\n", $1, $2, $3 ; }` [download] Output: `[foo] [123] [ sdjflsdfjklsfj ] [bar] [42] [ fkjfjklsfjs] [zoot] [23] [ ff ] [nooka] [9] [ ]` [download] Otherwise, if you want to capture the beginning of the string up to the = sign as the keyword regardless of content, maybe this is what you want: `#! /usr/bin/perl use strict ; use warnings ; my @str = ( 'fdjsflsdfjk foo=123 sdjflsdfjklsfj ', 'sdfhsdfsd bar=42 fkjfjklsfjs', 'zoot=23 ff ', ' nooka=9 ' ) ; foreach (@str) { /^([^=]+)=([[:digit:]]{1,3})(.)$/ ; printf "[%s] [%s] [%s]\n", $1, $2, $3 ; }` [download] Output: `[fdjsflsdfjk foo] [123] [ sdjflsdfjklsfj ] [sdfhsdfsd bar] [42] [ fkjfjklsfjs] [zoot] [23] [ ff ] [ nooka] [9] [ ]` [download] Hope that helps. :-) _______________ D a m n D i r t y A p e Home Node \| Email	[reply] [d/l] [select]
Re: Regex problem by screamingeagle (Curate) on Jul 05, 2002 at 00:14 UTC
this regex seems to work too : `m/^(.\s+keyword=)(\d+)(\s+.+)$/ (the +? has been replaced by )` [download]	[reply] [d/l]