Regex suggestion for this task

[dspitzle]

I'm trying to figure out a way of using regular expressionsm specifically ereg_replace(), to take an existing string and indent it. Specifically, I'd like to take a string like

line 1\nline 2\nline 3\n

and turn it into

\tline 1\n\tline 2\n\tline 3\n

Note that I don't want a tab after the final \n. Any suggestions on the correct regex?

 

[jpadie]

here is a non regex way to do it. did you specifically want regex? and if so, why would you chose ereg over preg?

function indent(){
 $return = str_replace ("\n", "\n\t", $string);
 if (substr($return, -1) === "\t"){
  $return = substr($return, 0, -1);
 }
 return $return;
}

 

[dspitzle]

I was hoping that a regular expression would save having to go back and trim the final instance of the inserted tabs. However, your solution might work. One thing I'm trying to figure out though is whether the substr calls in your solution would need to use -2 rather than -1, since "\t" is actually two characters in the strings (even though it gets echoed as a single character).

 

[jpadie]

treat as 1 character.

 

[dspitzle]

Are you 100% sure about that? The string actually contains the \ character and the t character. I would assume that doing a replace of all t characters or of all \ characters would affect the individual characters.

 

[jpadie]

i'm confident, yes. but why not try it yourself?

or read the manual?

http://fr2.php.net/manual/en/function.substr.php#79107