Does a case-insensitive comparison between two 7-bit ASCII
    strings.

    Format

      #include  <strings.h>

      int strncasecmp  (const char *s1, const char *s2, size_t n);

1 - Arguments

 s1

    The first of two strings to compare.

 s2

    The second of two strings to compare.

 n

    The maximum number of bytes in a string to compare.

2 - Description

    The strncasecmp function is case-insensitive. The returned
    lexicographic difference reflects a conversion to lowercase.
    The strncasecmp function is similar to the strcasecmp function,
    but also compares size. If the size specified by n is read before
    a NULL, the comparison stops.

    The strcasecmp function works for 7-bit ASCII compares only. Do
    not use this function for internationalized applications.

3 - Return Value

    n                  An integer value greater than, equal to, or
                       less than 0 (zero), depending on whether s1 is
                       greater than, equal to, or less than s2.