Re: Lost in Perl - text file searching and printing

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Re^2: Lost in Perl - text file searching and printing by slygon (Initiate) on Jul 23, 2011 at 22:44 UTC
Thanks for your replies! I am getting closer to understanding this... a bit of clarification: Yes, the text file can contain lines that do not contain the word "it". So, I need it to look for lines that match both the punctuation, and then containing the word "it", I have it selecting the correct text now based on the previous reply and some modification, but can't figure out how to only print the text AFTER that word... any advise? (I hope to understand this stuff yet... Perl regular expressions are a bit cryptic!!! Thanks again! Eric	[reply]
Re^3: Lost in Perl - text file searching and printing by zentara (Cardinal) on Jul 24, 2011 at 11:37 UTC
Well here is a 2 step solution. It still may have a problem if you encounter lines with 2 or more 'it' in them. Its called regex greediness. See greediness . I leave you some work to fix the possible greediness issue. :-) `#!/usr/bin/perl use strict; use warnings; while (<DATA>) { if ( $_ =~ m/([?.,]$)/){ # print " matching first criteria $_"; #now check for 'it', using capture parenthesis #for the text before and after 'it' if ( $_ =~ m/(.)it(.)/ ){ print "$2\n"; # the second capture parenthesis } }; } __DATA__ 4 score, and 7 years ago? our ? forefathers came, upon it -- a continent. it was it was it ? foo? .bar bazz __END__` [download] I'm not really a human, but I play one on earth. Old Perl Programmer Haiku ................... flash japh	[reply] [d/l]
Re^2: Lost in Perl - text file searching and printing by JavaFan (Canon) on Jul 23, 2011 at 22:58 UTC
Uhm, it's a bit pointless to replace what you match by itself. `m//` instead of `s///` is way better. But what's worse, you're printing the matching line, followed by the comma, dot, or question mark that was matched. The OP wants to print everything following the word `it`. There's no `it` in your pattern.	[reply] [d/l] [select]
Re^3: Lost in Perl - text file searching and printing by slygon (Initiate) on Jul 24, 2011 at 00:07 UTC
Thanks again for the input! The text file I am reading in is a couple of paragraphs of text from an article about Perl. One of the lines that the program should find is: Server (PAUSE) and it was happily feeding modules through to the CPAN archive sites. The output of the program, seeing the punctuation at the end, and the word "it" in the line would be : was happily feeding modules through to the CPAN archive sites. My program finds that line now, but it prints the entire line, not just what comes after "it". Any thoughts? Thanks! Eric	[reply]
Re^4: Lost in Perl - text file searching and printing by CountZero (Bishop) on Jul 24, 2011 at 06:53 UTC
My program finds that line now, but it prints the entire line, not just what comes after "it". Any thoughts? It would surely help if we could see your program. CountZero A program should be light and agile, its subroutines connected like a string of pearls. The spirit and intent of the program should be retained throughout. There should be neither too little or too much, neither needless loops nor useless variables, neither lack of structure nor overwhelming rigidity." - The Tao of Programming, 4.1 - Geoffrey James	[reply]
Re^4: Lost in Perl - text file searching and printing by JavaFan (Canon) on Jul 24, 2011 at 08:16 UTC
My program finds that line now, but it prints the entire line, not just what comes after "it". Any thoughts? Thanks! Eric Uhm, the first reply to your original question contains two answers. I know it wasn't invisible, because it received more downvotes than upvotes. But there was no reply to it. If that answer doesn't work for you, please reply to it with specific questions. Thanks! JavaFan	[reply]