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May 3, 2015 14:48
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blockgrep.pl
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| #!/usr/bin/perl | |
| use strict; | |
| =head1 SYNOPSIS | |
| grepblock.pl <start_of_block_regexp> <match_regexp> file1 file2 ... fileN | |
| Input files are split in blocks. Each block is delimited by `start_of_block_regexp`. | |
| Output those blocks that match `match_regexp` (/match_regexp/ms is used). | |
| =cut | |
| use Pod::Usage; | |
| use constant MAX_BLOCK_SIZE => 1048576; | |
| if (@ARGV < 3) { | |
| pod2usage(1); | |
| exit 1; | |
| } | |
| my $start_of_block_regexp = shift; | |
| my $match_regexp = shift; | |
| my $state = 'bob'; | |
| my $block = <>; | |
| while (<>) { | |
| my $line = $_; | |
| if ($state ne 'bob' and $line =~ /$start_of_block_regexp/s) { | |
| $state = 'bob'; | |
| print $block if $block =~ /$match_regexp/ms; | |
| $block = $line; | |
| } else { | |
| $state = 'scanning'; | |
| $block .= $line; | |
| die "Current block is getting too big, giving up..." if length($block) > MAX_BLOCK_SIZE; | |
| } | |
| } | |
| print $block if ($state ne 'bob' and $block =~ /$match_regexp/ms); |
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