Re: regex issue

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Re^2: regex issue by 7stud (Deacon) on Nov 11, 2010 at 00:16 UTC
...or more legibly `use strict; use warnings; use IO::Handle; my $current_line_num; while (my $line = <DATA>) { $current_line_num = DATA->input_line_number(); if( $current_line_num >= 2 and $current_line_num <= 7) { print $line; } }` [download] And if the file is only 100 or so lines long, how about an array slice? `for ( (<DATA>)[1..6] ) { print; }` [download]	[reply] [d/l] [select]
Re^3: regex issue by johngg (Canon) on Nov 11, 2010 at 11:51 UTC
...or more legibly I think you might be obscuring the wood with a lot of trees there! Perhaps use of the `-n` switch would be applicable here, either in a script or as a one-liner. `$ cat rubbish Line1 Line2 Line3 Line4 Line5 Line6 Line7 Line8 Line9 Line10 Line11 Line12 $ perl -ne 'print if 2 .. 7;' rubbish Line2 Line3 Line4 Line5 Line6 Line7 $` [download] The array slice method is, as you say, only suitable for small files whereas using `-n` when combined with last is more efficient when interested only in lines at the beginning of large files. The following examples were acting on a 2,000,000+ line log file. `# time perl -ne 'print if 5 .. 10' maillog Nov 11 04:19:28 ... Nov 11 04:19:28 ... Nov 11 04:19:28 ... Nov 11 04:19:28 ... Nov 11 04:19:28 ... real 0m1.206s user 0m0.773s sys 0m0.432s # time perl -ne 'print if 5 .. 10; last if $. > 10' maillog Nov 11 04:19:28 ... Nov 11 04:19:28 ... Nov 11 04:19:28 ... Nov 11 04:19:28 ... Nov 11 04:19:28 ... real 0m0.013s user 0m0.006s sys 0m0.008s #` [download] I hope this is of interest. Cheers, JohnGG	[reply] [d/l] [select]
Re^2: regex issue by pinnacle (Acolyte) on Nov 10, 2010 at 23:51 UTC
It works!! thanks	[reply]


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