read between two strings

harry34 has asked for the wisdom of the Perl Monks concerning the following question:

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Re: read between two strings by Rhose (Priest) on May 16, 2002 at 15:07 UTC
You could use the flip-flop operator to skip lines which are not between the %%Atom Coords and %%End Frame markers. Maybe something like this? `#!/usr/bin/perl -w use strict; while (<DATA>) { #-- Skip lines not in the section to be processed next unless /^%%Atom Coords/../^%%End Frame/; #-- Skip the section markers next if (/^%%Atom Coords/ or /^%%End Frame/); #-- Parse lines... print; } __DATA__ %%Atom Coords -1.13 12.16 6.15 %%End Frame more stuff... and more stuff... %%Atom Coords -2.26 24.32 12.30 %%End Frame` [download]	[reply] [d/l]
•Re: Re: read between two strings by merlyn (Sage) on May 16, 2002 at 15:13 UTC
`#-- Skip lines not in the section to be processed next unless /^%%Atom Coords/../^%%End Frame/; #-- Skip the section markers next if (/^%%Atom Coords/ or /^%%End Frame/);` [download] It's bad coding practice to write and test those twice, and you don't need to, if you pay attention to the return value: `my $inrange = /^%%Atom Coords/../^%%End Frame/; next unless $inrange; next if $inrange == 1 or $inrange =~ /E/; # skip first and last item + of range` [download] Very simple. RTFM. -- Randal L. Schwartz, Perl hacker	[reply] [d/l] [select]
(wil) Re: read between two strings by wil (Priest) on May 16, 2002 at 15:07 UTC
I'm not the best when it comes to regex's, but I would use something like this: `my $s = qq\|%%Atom Coords -1.13 12.16 6.15 %%End Frame\|; $s =~ s/^%%Atom Coords\s(.)\s*%%End Frame$/$1/; print $s;` [download] May I also suggest (and I will suggest this to myself, too ;-)) that you pick up a good book on this subject. - wil	[reply] [d/l]