php man page for strncmp

STRNCMP(3)								 1								STRNCMP(3)

strncmp - Binary safe string comparison of the first n characters

SYNOPSIS
       int strncmp (string  $str1, string  $str2, int  $len)

DESCRIPTION
	This  function	is  similar to strcmp(3), with the difference that you can specify the (upper limit of the) number of characters from each
       string to be used in the comparison.

	Note that this comparison is case sensitive.

PARAMETERS
	      o $str1
		- The first string.

	      o $str2
		- The second string.

	      o $len
		- Number of characters to use in the comparison.

RETURN VALUES
	Returns < 0 if $str1 is less than $str2; > 0 if $str1 is greater than $str2, and 0 if they are equal.

SEE ALSO
       strncasecmp(3), preg_match(3), substr_compare(3), strcmp(3), strstr(3), substr(3).

PHP Documentation Group 														STRNCMP(3)