Search for a string in file

[Shankye]

Hi friends ..

I have a mailing_list file ..

I wanted to check whether the visitor entered Email already exists in file?

Is there any standard function for it ?

Quite a few ways to do this. A trivial way would be:

1) place file into a variable (string) with file_get_contents().
2) check string for the email by using stripos().

** For checking with stripos - you MUST use the ' === false ' comparison, otherwise you could get the wrong result. See the php manual for details.

However, regex may be a better option.

[Shankye]

Thank you Ardav ...

I used almost similar method..

used

$string_Array = file(File_name) ;
$key = 0;

	while($strings[$key])
	{
		if( trim($strings[$key]) == $email)
		{
			header("Location: emailUsed.html");
		}
			$key++;
	 }

// continue to store email-ID in mail_list ...

Its working for now ..

Any suggestion on it?

[mschroeder]

Performance wise, you should avoid loading an entire file into memory when possible.
The following code relies on the SPL (standard php library) which is mostly > php 5.1
Although this can also be done using the file functions in php.

<?php
$email = '[e-mail]';

$file = new SplFileObject('filename.txt');
$file->setFlags(SplFileObject::DROP_NEW_LINES);

$match = false;
foreach($file as $line){
	if( false !== stripos( $line, $email ) ){
		$match = true;
		break;
	}
}

if( true === $match ){
	//we found a match
} else {
	//No Match
}

This reads through a file while only having a single line in memory at a time.
If/when it finds a match, it sets $match = true, you could implement this however you would like, but then breaks out of the foreach loop to stop from having to check the rest of the file.

If you're using a version of php that supports the SplFileObject you should really check it out. http://php.net/manual/en/class.splfileobject.php

[Shankye]

Thank you soooooo much mschroeder..
It helped a lot ...
Its really faster now..