(PHP 4 >= 4.0.2, PHP 5)
strncasecmp — Binary safe case-insensitive string comparison of the first n characters
This function is similar to strcasecmp(), with the difference that you can specify the (upper limit of the) number of characters from each string to be used in the comparison.
The first string.
The second string.
The length of strings to be used in the comparison.
Returns < 0 if str1 is less than str2; > 0 if str1 is greater than str2, and 0 if they are equal.