Match upper and lower case

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

Replies are listed 'Best First'.
Re: Match upper and lower case by Zaxo (Archbishop) on Jan 29, 2005 at 04:29 UTC
Use the /i flag for case-insensitive match. `if (/error/i) { #. . . }` [download] or `my $erre = qr/error/i; $str =~ $erre snd # . . .` [download] After Compline, Zaxo	[reply] [d/l] [select]
Re: Match upper and lower case by gopalr (Priest) on Jan 29, 2005 at 04:59 UTC
Hi, use '`i`' for ignore case. `if ($_=~m#error#i) { .. ## It'll match whole 'error' }` [download]	[reply] [d/l] [select]
Re: Match upper and lower case by jimrobertsiii (Scribe) on Jan 29, 2005 at 04:56 UTC
IMHO TMTOWTDI `if (uc $error eq "ERROR"){ # . . . }` [download] or `if (lc $error eq "error"){ # . . . }` [download] Although, I would prefer Zaxo's first example because it seems more efficient (if for no other reason, but conservation of code :-) -Jim	[reply] [d/l] [select]
Re^2: Match upper and lower case by blazar (Canon) on Jan 30, 2005 at 15:04 UTC
IMHO TMTOWTDI `if (uc $error eq "ERROR"){ # . . . }` [download] or `if (lc $error eq "error"){ # . . . }` [download] Although, I would prefer Zaxo's first example because it seems more efficient (if for no other reason, but conservation of code :-) Note that this is not strictly equivalent to Zaxo's code since `/error/i` checks (case insensitively) for the presence of the string 'error' and not for equality to it (up to case insentiveness). More importantly: "more efficient"? Well, I premise that I'd probably use `/error/i` or `/^error$/i` (this really depends on what can there be in `$_`) myself in most reasonable cases, but running `#!/usr/bin/perl use strict; use warnings; use Benchmark qw/:all :hireswallclock/; my $test_str='error'; my @test=map { my @chr=("\0", " "); local $_=$test_str; s/./$& ^ $chr[rand 2]/ge} 1..100; no warnings 'void'; cmpthese -30, { regex => sub { /^\Q$test_str\E$/i for @test }, lc => sub { $test_str eq lc for @test} }, 'all'; __END__` [download] I get `Benchmark: running lc, regex for at least 30 CPU seconds... lc: 34.068 wallclock secs (34.10 usr 0.00 sys + 0.00 cusr 0 +.00 csys = 34.10 CPU) @ 19917.24/s (n=679178) regex: 31.518 wallclock secs (31.53 usr 0.00 sys + 0.00 cusr 0 +.00 csys = 31.53 CPU) @ 13689.50/s (n=431630) Rate regex lc regex 13690/s -- -31% lc 19917/s 45% --` [download] and `Benchmark: running lc, regex for at least 30 CPU seconds... lc: 31.4462 wallclock secs (31.45 usr 0.00 sys + 0.00 cusr +0.00 csys = 31.45 CPU) @ 26138.57/s (n=822058) regex: 31.8579 wallclock secs (31.86 usr 0.00 sys + 0.00 cusr +0.00 csys = 31.86 CPU) @ 14326.49/s (n=456442) Rate regex lc regex 14326/s -- -45% lc 26139/s 82% --` [download] under Windows 98 and Linux (kernel 2.6.10) respectively. Perl 5.8.6 in both cases...	[reply] [d/l] [select]
Re: Match upper and lower case by jbrugger (Parson) on Jan 29, 2005 at 19:54 UTC
I downvoted you here, i strongly believe that these kind of questions can be found if a little effort would be put in searching older nodes, google, perldoc, books etc. (and so you learn more too!) This is imho not a question belonging here anymore (and cirtenly not at The Monastery Gates), thinking, reading and searching should be done before asking, this is lazy.	[reply]
Re^2: Match upper and lower case by foil (Sexton) on Jan 29, 2005 at 21:36 UTC
Jbrugger, I agree, but maybe the better question is why this question was approved and front-paged ?? node_id=17688 explains the process . Not the first loose approval lately, I think .	[reply]
Re^3: Match upper and lower case by ysth (Canon) on Jan 30, 2005 at 10:07 UTC
Nothing wrong with approving this node that I can see. If we didn't approve questions that could be self-answered by 30 or less minutes of searching/reading, we wouldn't have very many approved questions.	[reply]
Re^4: Match upper and lower case by foil (Sexton) on Jan 30, 2005 at 17:28 UTC
Re^5: Match upper and lower case by ysth (Canon) on Feb 02, 2005 at 06:47 UTC
Re^2: Match upper and lower case by DrHyde (Prior) on Jan 31, 2005 at 10:11 UTC
It's at least possible that someone might have looked for documentation but because they were using the wrong keywords not have found anything useful. However, I too downvoted this node because the poster didn't even say that he had looked, let alone where he had looked.	[reply]