Variable in regexp

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

Suppose I want to use a variable in a regular expression like this: /$var_*/ I want the regular expression to mach the content of the variable and a underscore plus something else. But the complier offcourse assumes that the name of the variable is $var_ and says that there is no such variable. So what do you suggest me to do. Thank you for any help.

Comment on Variable in regexp Download Code

Replies are listed 'Best First'.
Re: Variable in regexp by jwkrahn (Abbot) on Mar 22, 2011 at 00:20 UTC
Put the variable name in braces like this: `/${var}_*/`.	[reply] [d/l]
Re: Variable in regexp by toolic (Bishop) on Mar 22, 2011 at 00:25 UTC
Another way is to use whitespace in the regex with the `//x` modifier (perlre) `/ $var _ /x` [download]	[reply] [d/l] [select]
Re^2: Variable in regexp by JavaFan (Canon) on Mar 22, 2011 at 01:33 UTC
The disadvantage is that that only works in patterns. The `${var}_` method also works in double quoted strings.	[reply] [d/l]
Re: Variable in regexp by umasuresh (Hermit) on Mar 22, 2011 at 10:41 UTC
Are you expecting something like this? `my $var = "only"; my $str = "only_once"; if($str =~ /($var)\_(.*)/) { print "$1\t$2\n"; }` [download]	[reply] [d/l]