NAME    [Toc]    [Back]

       toupper, tolower - convert letter to upper or lower case

SYNOPSIS    [Toc]    [Back]

       #include <ctype.h>

       int toupper (int c);
       int tolower (int c);

DESCRIPTION    [Toc]    [Back]

       toupper() converts the letter c to upper case, if possible.

       tolower() converts the letter c to lower case, if possible.

       If  c  is  not  an  unsigned char value, or EOF, the behaviour of these
       functions is undefined.

RETURN VALUE    [Toc]    [Back]

       The value returned is that of the converted letter, or c if the conversion
 was not possible.

CONFORMING TO    [Toc]    [Back]

       ANSI C, BSD 4.3

BUGS    [Toc]    [Back]

       The details of what constitutes an uppercase or lowercase letter depend
       on the current locale.  For example, the default "C"  locale  does  not
       know about umlauts, so no conversion is done for them.

       In some non - English locales, there are lowercase letters with no corresponding
 uppercase equivalent; the German sharp s is one example.

SEE ALSO    [Toc]    [Back]

       isalpha(3), setlocale(3), locale(7)



GNU				  1993-04-04			    TOUPPER(3)