[php] Matching a space in regex

I need to match a space character in a PHP regular expression. Anyone got any ideas?

I mean like "gavin schulz", the space in between the two words. I am using a regular expression to make sure that I only allow letters, number and a space. But I'm not sure how to find the space. This is what I have right now:

$newtag = preg_replace("/[^a-zA-Z0-9s|]/", "", $tag);

Here is a everything you need to know about whitespace in regular expressions:

• [[:blank:]] Space or tab only
• [[:space:]] Whitespace
• \s Any whitespace character
• \v Vertical whitespace
• \h Horizontal whitespace
• x Ignore whitespace

Use it like this to allow for single space.

$newtag = preg_replace("/[^a-zA-Z0-9\s]/", "", $tag)

\040 matches exactly the space character.

Regexp PHP reference

New Link
Escape sequences for Regex PHP

I am using a regex to make sure that I only allow letters, number and a space

Then it is as simple as adding a space to what you've already got:

$newtag = preg_replace("/[^a-zA-Z0-9 ]/", "", $tag);

(note, I removed the s| which seemed unintentional? Certainly the s was redundant; you can restore the | if you need it)

If you specifically want *a* space, as in only a single one, you will need a more complex expression than this, and might want to consider a separate non-regex piece of logic.

I'm trying out [[:space:]] in an instance where it looks like bloggers in WordPress are using non-standard space characters. It looks like it will work.

You can also use the \b for a word boundary. For the name I would use something like this:

[^\b]+\b[^\b]+(\b|$)

EDIT Modifying this to be a regex in Perl example

if( $fullname =~ /([^\b]+)\b[^\b]+([^\b]+)(\b|$)/ ) {
 $first_name = $1;
 $last_name = $2;
}

EDIT AGAIN Based on what you want:

$new_tag = preg_replace("/[\s\t]/","",$tag);

It seems to me like using a REGEX in this case would just be overkill. Why not just just strpos to find the space character. Also, there's nothing special about the space character in regular expressions, you should be able to search for it the same as you would search for any other character. That is, unless you disabled pattern whitespace, which would hardly be necessary in this case.

In Perl the switch is \s (whitespace).