Help on Regex

[rajiv07]

Hi to all,

I have regex related pl fie below.when i execute the file it gives some error.

[CODE=perl]#!/usr/bin/perl
my @array=('324234 2','fdsfsd4432' );

my $file='D:/HTTP/sample/SAREGAMA/HINDI/01/INH100155170 O HANSINI(ZEHREEL A INSAAN.wma';

my @ee=grep(/^$file$/,@array);

print @ee;[/CODE]


My error

Unmatched ( in regex; marked by <-- HERE in m/^D:/HTTP/sample/SAREGAMA/HINDI/01/INH100155170 O HANSINI( <-- HERE ZEHREELA INSAAN.wma$/ at C:\DOCUME~1\IND IAM~1.COM\LOCAL S~1\Temp\locB8. tmp line 9.

Please Help on this.

regards Rajiv.

[rajiv07]

I got the point now if the string contain regex special character like $,^ ) we have to escape the character.

Regards
Rajiv

[nithinpes]

Hi to all,

I have regex related pl fie below.when i execute the file it gives some error.

[CODE=perl]#!/usr/bin/perl
my @array=('324234 2','fdsfsd4432' );

my $file='D:/HTTP/sample/SAREGAMA/HINDI/01/INH100155170 O HANSINI(ZEHREEL A INSAAN.wma';

my @ee=grep(/^$file$/,@array);

print @ee;[/CODE]


My error

Unmatched ( in regex; marked by <-- HERE in m/^D:/HTTP/sample/SAREGAMA/HINDI/01/INH100155170 O HANSINI( <-- HERE ZEHREELA INSAAN.wma$/ at C:\DOCUME~1\IND IAM~1.COM\LOCAL S~1\Temp\locB8. tmp line 9.

Please Help on this.

regards Rajiv.

Change this line:

my @ee=grep(/^$file$/,@array);

to :

my @ee=grep(/^\Q$file\E$/,@array);

In your case, $file contains forward slashes which will mess up the regex(as they stand for pattern delimiters). Even using double quotes and escaping the slashes will not work.
If you put a pattern between \Q and \E, any special meaning of the characters in pattern match will be ignored (variable substitutions will be allowed). For ex:
/\Q.*?\E/ will match '.*?'

[rajiv07]

Change this line:

my @ee=grep(/^$file$/,@array);

to :

my @ee=grep(/^\Q$file\E$/,@array);

In your case, $file contains forward slashes which will mess up the regex(as they stand for pattern delimiters). Even using double quotes and escaping the slashes will not work.
If you put a pattern between \Q and \E, any special meaning of the characters in pattern match will be ignored (variable substitutions will be allowed). For ex:
/\Q.*?\E/ will match '.*?'

Thank You Nithin,

Why cannot we use escape the special regex char.its also working fine.Is any problem will occur when using this concept,if so please let me know and could u suggest any regexp site to refer.

Regards

Rajiv

[nithinpes]

Thank You Nithin,

Why cannot we use escape the special regex char.its also working fine.Is any problem will occur when using this concept,if so please let me know and could u suggest any regexp site to refer.

Regards

Rajiv

Sorry for the confusion and missed phrase. I mean to say: "Even using double quotes and escaping the slashes will not be a tidy work" (as it includes n number of slashes, dots & probably other characters).
So, instead of escaping each & every special characters, using \Q and \E would be crisp and easy.