PHP and Regual Expressions

[mike_robb]

I'm trying to write a regular expression statement to remove all spaces except for one space that follows one of two strings:

$str1="abc def ghi klmn op qrs tuv";

$str2=func($str1);

where $str2 should be equal to:
"abc def ghiklmnopqrstuv";

func is a function defined like:
function func($i)
{
$j=ereg_replace("[ \t]","",$i);
return $j;
}

This will just remove all spaces (and tabs).

How do I use one ereg_replace statement to remove all double spaces, and all single spaces that don't follow one of two given string patters?

Any ideas?

TIA-

--Mike
http://sporum.org/

[Weedpacket]

It would be a lot easier to use preg_replace

$j = preg_replace('/(?<!string1)(?<!string2)\\s/', $i);

It basically says exactly what you're asking for: "remove whitespace that is not preceded by string1 or by string2" (where "string1" and "string2" are the strings you don't want it stripped after).

[mike_robb]

thats some great code 🙂

if i could throw a twist now...

i don't want to remove any spaces that are inside of matching quotes or tics. is this possible or getting too complex for reg-exp?

$str="ab '  def  ' ghi' ";

should become:
$str="ab'  def  'ghi'";

any ideas?

TAI-

--Mike
http://sporum.org/

[Weedpacket]

Originally posted by mike_robb
i don't want to remove any spaces that are inside of matching quotes or tics. is this possible or getting too complex for reg-exp?

Getting that way. It would be easier to break the string into a list of bits inside and outside quotes, and then work on the bits outside. explode or maybe preg_split. If it's just quotes, then explode ("'", $string) would give an array of pieces - odd-numbered ones are inside quotes, even-numbered ones are outside. Then, I guess, when you're processing the even-numbered (i.e., outside-quotes) pieces, you'd explode on to isolate bits that are inside from those that are outside.