Strip tabs from multi-line string

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

Hi i've been using regular expressions for quite some time now and i have a problem with a very simple one.

The regular expression is supposed to take in a multiline string and strip out any tabs found in the string using this regular expression

$actionData =~ tr/\t//sm;
[download]

as i understand it tr transposes the first chunk to the second chunk in this case \t (tab) to nothing.

and sm will process the string as a multiline string.

Thanks in advance

Karl

edited by ybiC: retitle from "Problematic regular expression"

Comment on Strip tabs from multi-line string Download Code

Replies are listed 'Best First'.
(jeffa) Re: Strip tabs from multi-line string by jeffa (Bishop) on Jul 28, 2003 at 14:57 UTC
pick one: `$actionData =~ tr/\t//d;` [download] or `$actionData =~ s/\t//g;` [download] Since you aren't dealing with . or anchors, the m and s modifiers for `s///` are not necessary. jeffa L-LL-L--L-LL-L--L-LL-L-- -R--R-RR-R--R-RR-R--R-RR B--B--B--B--B--B--B--B-- H---H---H---H---H---H--- (the triplet paradiddle with high-hat)	[reply] [d/l] [select]
Re: Strip tabs from multi-line string by diotalevi (Canon) on Jul 28, 2003 at 14:58 UTC
That isn't a regular expression. It sort of looks like one but its not. In fact, that's a transliteration and it doesn't use the /sm flags. You wanted either `tr/\t//d` or `s/\t+//g`.	[reply] [d/l] [select]
Re: Strip tabs from multi-line string by Lachesis (Friar) on Jul 28, 2003 at 15:04 UTC
I think you might be confusing transliteration with substitution When you use the tr operator you only have 3 options ( copied from perldoc perlop) c Complement the SEARCHLIST. d Delete found but unreplaced characters. s Squash duplicate replaced characters. If you want to strip out tabs using tr you would do something like `$actionData =~ tr/\t//d;` The substitution equivalent would be `$actionData =~ s/\t//g`	[reply] [d/l] [select]
OT Sidebar, was Re: Strip tabs from multi-line string by RMGir (Prior) on Jul 28, 2003 at 16:11 UTC
My first reaction when I saw tr///sm was a Princess Bride flashback: "...that word. I do not think it means what you think it means." =) -- Mike	[reply]
Re: Strip tabs from multi-line string by klattimer (Initiate) on Jul 28, 2003 at 15:01 UTC
Thank you both ;))	[reply]