how do i get the 2nd line when the 1st is matched

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

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Re: how do i get the 2nd line when the 1st is matched (quicky) by tye (Sage) on Aug 17, 2004 at 04:32 UTC
Since you are impatient (in the chatterbox), here is a quicky way: `while( <> ) { if( /\Qsid=167216582&ID=116\E/ ) { my $nextLine= <>; print $nextLine; } }` [download] A bit shy on details, just like your question. (: - tye	[reply] [d/l]
Re^2: how do i get the 2nd line when the 1st is matched (even quickier) by ysth (Canon) on Aug 17, 2004 at 06:45 UTC
`$ egrep -A1 some-pattern in-files\|grep -v '<option'` [download]	[reply] [d/l]
Re: how do i get the 2nd line when the 1st is matched by Zaxo (Archbishop) on Aug 17, 2004 at 04:34 UTC
With the obligatory warning that you should be using some HTML::Parser module, here is how to conditionally get the next line. `# $re is the pattern to match my @next_lines; while (<FILE>) { push @next_lines, scalar(<FILE>) if /$re/; }` [download] The scalar call is needed to override list context. Without it, the diamond op would return the rest of the file. After Compline, Zaxo	[reply] [d/l]
Re: how do i get the 2nd line when the 1st is matched by ikegami (Patriarch) on Aug 17, 2004 at 04:33 UTC
One way is to treat both lines as one... `($match) = $text =~ /whatever_you_already_have\s*(\S+)/s`	[reply] [d/l]
Re^2: how do i get the 2nd line when the 1st is matched by Aristotle (Chancellor) on Aug 17, 2004 at 08:56 UTC
Are you sure that pattern is what you want? It demands that the string be followed by any amount of whitespace (including none!), followed by at least one character of non-whitespace which will be capture. Here are some things it will match: `$text = "whatever_you_already_havefoobar\n"; # $1 eq "foobar" $text = "whatever_you_already_have foo\nbar"; # $1 eq "foo" $text = "whatever_you_already_have\nfoobar"; # $1 eq "foobar" $text = "whatever_you_already_have\nfoo bar"; # $1 eq "foo"` [download] You probably meant something more along the lines of `/whatever_you_already_have.\n(.)/` [download] Or if you want to do it using `/s` for other reasons, `/whatever_you_already_have[^\n]\n([^\n])/s` [download] Makeshifts last the longest.	[reply] [d/l] [select]
Re^3: how do i get the 2nd line when the 1st is matched by ikegami (Patriarch) on Aug 17, 2004 at 14:43 UTC
Aye, the solution can be adapted to more complex input if required. Thanks for expanding on it.	[reply]
Re: how do i get the 2nd line when the 1st is matched by murugu (Curate) on Aug 17, 2004 at 05:36 UTC
Here is a way, `while (<DATA>){ if (/ID=136/)######## any condition to be satisfied to print next l +ine. { my $t=<DATA>;#### do what ever u want with $t print $t; } } __DATA__ option value="PDAConfig3.asp?sid=167216582&ID=136"> i705 <option value="PDAConfig3.asp?sid=167216582&ID=116"> III <option value="PDAConfig3.asp?sid=167216582&ID=118"> IIIc` [download]	[reply] [d/l]
Re: how do i get the 2nd line when the 1st is matched by johnnywang (Priest) on Aug 17, 2004 at 05:51 UTC
Somehow I do not like calling <> inside another <> (just a personal thing), so my first version would be something like: `my $match = 0; while(<INPUT>){ if($match){ print; $match = 0; } if(/<option value="PDAConfig3\.asp/i>{ $match = 1; } }` [download]	[reply] [d/l]
Re: how do i get the 2nd line when the 1st is matched by Mr_Micawber (Beadle) on Aug 18, 2004 at 01:18 UTC
Since TMTOWTDI how about this? (not as concise, but clearer (to me) ) `open( FILE, "<data.txt"); my @lines = (<FILE>); close FILE; my $i = 0; for(@lines){ chomp; print $_ if ( $lines[$i-1] =~ /116">$/ ) && ( $i ); $i++; }` [download] The second clause of the `if` conditional is to prevent the "wrap around" effect of a -1 array subscript.	[reply] [d/l] [select]