The
strcasecmp() and
strncasecmp() functions compare the nul-terminated strings
s1 and
s2 and return an integer greater than, equal to, or less than 0, according to whether
s1 is lexicographically greater than, equal to, or less than
s2 after translation of each corresponding character to lower-case. The strings themselves are not modified. The comparison is done using unsigned characters, so that ‘
\200' is greater than ‘\0'.
The
strncasecmp() compares at most
len characters.