How to extract certain range of text and write into another file?

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

Hi all, I have updated code as following, I wish to extract part of the text and write into another file. The loop of the code do not stop at my selected range of text. It read until the final match line of word. Please advise me. Thanks. For example, I need to extract the $ NAME: sandy until $$.TO and then join with the contents inside $NAME: patrick which is start from G1 until $$SRU. Any idea?

Text:
$ NAME : corry   
$$.Inc s d  
$$.Oc s 
$$.TO

G1 ty n1 EE EE M T1 T2 $$SRU   
G2 n1 y OO OO M T3 T4 $$SRU   
.EON  

$ NAME : patrick  
$$.Inc c d
$$.Oc c 
$$.TO 

G1 td n3 EE EE M T5 T6 $$SRU    
G2 n3 y OO OO M T7 T8 $$SRU  
.EON 

$ NAME : sandy    
$$.Inc k l
$$.Oc l
$$.TO

G1 td n3 FF FF M R5 R6 $$SRU      
G2 n3 y OO OO N R7 R8 $$SRU    
.EON
[download]

Code:
use strict;
use warnings;

open my $F1, '<', 'testing.txt' or die "failed $!";
open my $F2, '>', 'out.txt' or die "failed $!";

while (<$F1>) {
if (/^\$ NAME : sandy/../\$.TO/) {
print $F2 $_;
}
if (/^\$ NAME : patrick/../\$.EON/) {
if(/^G1/../\$SRU){
 s/G1/G1.G1o.n/g;
print $F2 $_;}
}

 }
close $F1;
close $F2;
[download]

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Re: How to extract certain range of text and display it? by moritz (Cardinal) on Oct 13, 2013 at 11:09 UTC
Your most obvious problem is that there is no occurrence of `Corry` in the test data, only `corry`. And no, the two are not the same. Another problem is that you use $1, but the regex before it doesn't use a capturing group that could fill $1. A third problem is that the iteration variable is `$word`, but the regexes match against $_, thus have no chance to succeed. I'm pretty sure you get an `uninitialized...` warning from that. Didn't you? Or did you just ignore it? (hint: never ignore the warning). Perl 6 - the future is here, just unevenly distributed	[reply] [d/l] [select]
Re^2: How to extract certain range of text and display it? by annel (Novice) on Oct 14, 2013 at 01:30 UTC
Hi, the problems you have mentioned are totally correct. I have correct the occurrence of `corry` and get rid of $word. I can't figure out what variable should I match the section text.	[reply] [d/l]
Re^3: How to extract certain range of text and display it? by Anonymous Monk on Oct 14, 2013 at 01:52 UTC
I can't figure out what variable should I match the section text. post the new code	[reply]
Re^4: How to extract certain range of text and display it? by annel (Novice) on Oct 14, 2013 at 02:05 UTC
Re^5: How to extract certain range of text and display it? by Anonymous Monk on Oct 14, 2013 at 02:18 UTC
Some notes below your chosen depth have not been shown here
Re: How to extract certain range of text and display it? by CountZero (Bishop) on Oct 13, 2013 at 12:25 UTC
Tell Perl that your records are terminated by "`.EON\n\n`". `use Modern::Perl; { local $/ = ".EON\n\n"; while ( my $record = <DATA> ) { say "I found: $record"; # ... now do something with $record ... } } __DATA__ $ NAME : corry $$.Inc s d $$.Oc s $$.TO G1 ty n1 EE EE M T1 T2 $$SRU G2 n1 y OO OO M T3 T4 $$SRU .EON $ NAME : patrick $$.Inc c d $$.Oc c $$.TO G1 td n3 EE EE M T5 T6 $$SRU G2 n3 y OO OO M T7 T8 $$SRU .EON` [download] 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 My blog: Imperial Deltronics	[reply] [d/l] [select]
Re^2: How to extract certain range of text and display it? by annel (Novice) on Oct 14, 2013 at 01:43 UTC
Hi, thanks for your response. I did it as following but nothing display of the output. `use warnings; use strict; my $test; my @words; open(INFO,"<","testing.pl")\|\|die"Can't open file:$!\n"; chomp (@words=<INFO>); close(INFO); local $/ = ".EOM\n\n"; while ( my $record = @words) { print $record; }` [download] Where did I make mistake?	[reply] [d/l]
Re^3: How to extract certain range of text and display it? by soonix (Chancellor) on Oct 14, 2013 at 08:45 UTC
CountZero's advice is more than just "setting $/". You have to define $/ before reading your file of course, spell your record separator correctly, as noted by jakeease change your logic accordingly, because a "record" now contains multiple lines (those belonging to one name)	[reply]
Re^4: How to extract certain range of text and display it? by annel (Novice) on Oct 15, 2013 at 05:34 UTC
Re^5: How to extract certain range of text and display it? by soonix (Chancellor) on Oct 15, 2013 at 08:44 UTC
Re^5: How to extract certain range of text and display it? by Anonymous Monk on Oct 15, 2013 at 06:48 UTC
Some notes below your chosen depth have not been shown here
Re^3: How to extract certain range of text and display it? by jakeease (Friar) on Oct 14, 2013 at 07:21 UTC
CountZero's suggestion is `local $/ = ".EON\n\n";` you simply have a typo:`".EOM`...	[reply] [d/l] [select]
Re: How to extract certain range of text and display it? by Anonymous Monk on Oct 13, 2013 at 10:58 UTC
Read perlintro#foreach and Simple matching and foreach, and either match against $word, or get rid of $word	[reply]
Re^2: How to extract certain range of text and display it? by annel (Novice) on Oct 14, 2013 at 01:20 UTC
Thanks for your suggestion. I read it and I have get rid of $word but still I can't get my output.	[reply]
Re: How to extract certain range of text and write into another file? by hdb (Monsignor) on Oct 15, 2013 at 09:05 UTC
I would recommend to first read all of your data into a datastructure, like a hash of hashrefs with the names as the keys and then process the data according to your logic: use strict; use warnings; use Data::Dumper; my @extract; while(<DATA>){ if /^\.EON/ or /^\s$/; push @extract, {name => $1} and next if /^\$ NAME : (\w+)/; ${$extract[-1]}{$1} = $2 if /(\S+)\s(.*)/; } my %result = map { delete $_->{name} => $_ } @extract; print Dumper \%result; __DATA__ $ NAME : corry $$.Inc s d $$.Oc s $$.TO G1 ty n1 EE EE M T1 T2 $$SRU G2 n1 y OO OO M T3 T4 $$SRU .EON $ NAME : patrick $$.Inc c d $$.Oc c $$.TO G1 td n3 EE EE M T5 T6 $$SRU G2 n3 y OO OO M T7 T8 $$SRU .EON $ NAME : sandy $$.Inc k l $$.Oc l $$.TO G1 td n3 FF FF M R5 R6 $$SRU G2 n3 y OO OO N R7 R8 $$SRU .EON [download]	[reply] [d/l]