5.18 strcasecmp—case-insensitive character string compare

Synopsis

     #include <strings.h>
     int strcasecmp(const char *a, const char *b);
     

Description
strcasecmp compares the string at a to the string at b in a case-insensitive manner.

If *a sorts lexicographically after *b (after both are converted to lowercase), strcasecmp returns a number greater than zero. If the two strings match, strcasecmp returns zero. If *a sorts lexicographically before *b, strcasecmp returns a number less than zero.

strcasecmp requires no supporting OS subroutines. It uses tolower() from elsewhere in this library.