removing any special characters in a string 1

[calabama]

Hello,
How does one remove any instances of special characters in a string.

Thanks In the begining
Let us first assume that there was nothing to begin with.

 

[rosenk]

That depends on what you mean by special characters. If you mean nonprintable characters you could do:
[tt]$string =~ s/[[:^print:]]//g;[/tt]

[tt][rint:][/tt] is the POSIX character class of printable characters, [tt][:^print:][/tt] is it's opposite.

 

[calabama]

Sorry Rosenk,

I guess it would have been nice to be more specific. I guess special characters means any characters that ate not A-Za-z0-9 characters.

Thanks In the begining
Let us first assume that there was nothing to begin with.

 

[rosenk]

In that case, you would do:
[tt]$string =~ s/[^A-Za-z0-9]//g;[/tt]

you can save some characters by using case insensitive regex instead:
[tt]$string =~ s/[^a-z0-9]//gi;[/tt]

or, if you don't mind getting _ (underscore) as well as alphanumeric, you can use \W (non-word character class):
[tt]$string =~ s/\W//g;[/tt]

 

[justice41]

and if you DO mind getting the underscore then you can use:

$string =~ s/[\W_]//g;

jaa

 

[calabama]

Thanks for your help,

I had another question though. I wanted to use the

$string =~ s/[^a-z0-9]//gi;

example.
Is there a way to adapt it to allow spaces as an exception.

Thanks again In the begining
Let us first assume that there was nothing to begin with.

 

[rosenk]

Surely. What the regexp is doing is replacing anything that matches that which is between the first slashes with that which is in the second. The regex between the first slashes [tt][^a-z0-9][/tt] means a character not ([tt]^[/tt]) matching anything between 'a' and 'z' (case ignored because of the [tt]i[/tt] modifier at the end) or '0'-'9'. Anything that does not match this pattern gets replaced with nothing.

If you want to allow spaces you would change the left part to: [tt][^a-z0-9 ][/tt] (notice space after the 9)... or if you want to allow any space-like character (including tab): [tt][^a-z0-9\s][/tt]