16.1.4.2 c-strcase

The c-strcase module contains case-insensitive string comparison functions operating on single-byte character strings, like the functions in <strings.h>, that operate as if the locale encoding was ASCII. (The "C" locale on many systems has the locale encoding "ASCII".)

The functions are:

extern int c_strcasecmp (const char *s1, const char *s2);
extern int c_strncasecmp (const char *s1, const char *s2, size_t n);

For case conversion here, only ASCII characters are considered to be upper case or lower case.

Note: The functions strcasecmp, strncasecmp from <strings.h> support only unibyte locales; for multibyte locales, you need the functions mbscasecmp, mbsncasecmp, mbspcasecmp.