Returning line numbers of a string

pts491 has asked for the wisdom of the Perl Monks concerning the following question:

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Re: Returning line numbers of a string by BrowserUk (Patriarch) on Aug 12, 2012 at 23:26 UTC
`perl -nle"/thesearchstring/ && print $." theFile` [download] With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice. The start of some sanity?	[reply] [d/l]
Re: Returning line numbers of a string by Marshall (Canon) on Aug 12, 2012 at 22:43 UTC
Adjust as you will: `#!/usr/bin/perl -w use strict; while (<DATA>) { print "$. $_"; # $. is current line number } =prints 1 some line 1 2 some line 2 3 some line 3 =cut __DATA__ some line 1 some line 2 some line 3` [download]	[reply] [d/l]
Re: Returning line numbers of a string by Old_Gray_Bear (Bishop) on Aug 12, 2012 at 22:47 UTC
In pseudo-code: `open log-file set line-counter to 0 read the log-file a line at a time add one to the line-counter if the pattern is found, then then print "I found pattern at ", line-counter once the file is completely read, close log-file print "We Are Done!!" exit` [download] Let us know when you get stuck implementing this in Perl. ---- I Go Back to Sleep, Now. OGB	[reply] [d/l]
Re: Returning line numbers of a string by Anonymous Monk on Aug 12, 2012 at 22:54 UTC
It is called "grep."	[reply]
Re: Returning line numbers of a string by pvaldes (Chaplain) on Aug 13, 2012 at 17:31 UTC
`open my $file, '<', "myfilename"; while (<$file>){ next unless /mystring/; print "string found at line $."; } close $file;` [download]	[reply] [d/l]
Re: Returning line numbers of a string by pvaldes (Chaplain) on Aug 13, 2012 at 17:28 UTC
oups... duplicated message, sorry. to be reaped	[reply]