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Substituting // for last match in a string

rwb2314460
Novice

Aug 29, 2002, 10:18 AM

Post #1 of 4 (8580 views)

Substituting // for last match in a string	Can't Post

I need to be able to strip off the last underscore and everything that follows that character.
For example if I have the string
"text_text_20020829.dat"
I want to be returned the string
"text_text".

Or if I have the string
"text_20020829.dat"
I want to be returned the string
"text".

Any assistance would be appreciated.

Thanks,
Bob

Paul
Enthusiast

Aug 29, 2002, 10:53 AM

Post #2 of 4 (8577 views)

Re: [rwb2314460] Substituting // for last match in a string [In reply to]	Can't Post

Code

my $var = 'abc_123_def.dat'; 
 
$var = substr($var, 0, rindex($var, '_'));

I know it isn't a regex but it may be a bit quicker :)

But if you need case insensitivity or something use:

Code

$file =~ s/_.*$//i;

(This post was edited by RedRum on Aug 29, 2002, 10:55 AM)

davorg
Thaumaturge / Moderator

Aug 30, 2002, 9:10 AM

Post #3 of 4 (8560 views)

Re: [RedRum] Substituting // for last match in a string [In reply to]	Can't Post

Code

$file =~ s/_.*$//i;

That doesn't work if there is more than one _ in the string.

Code

$_ = "text_text_20020829.dat"; 
 
s/_.*$//i; 
 
print; # prints "text"

Try this instead.

Code

s/_[^_]*$//i;

But you're right that the substr/rindex solution is probably faster.

--
Dave Cross, Perl Hacker, Trainer and Writer
http://www.dave.org.uk/
Get more help at Perl Monks

Paul
Enthusiast

Aug 30, 2002, 9:13 AM

Post #4 of 4 (8559 views)

Re: [davorg] Substituting // for last match in a string [In reply to]	Can't Post

Whoops I forgot the ? but I should have used [^_]* anyway.

(This post was edited by RedRum on Aug 30, 2002, 9:13 AM)

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