toupper

TOUPPER(3)		  Linux Programmer’s Manual		   TOUPPER(3)



NAME
       toupper, tolower - convert letter to upper or lower case

SYNOPSIS
       #include <ctype.h>

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

DESCRIPTION
       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
       The value returned is that of the converted letter, or c if  the	 con-
       version was not possible.

CONFORMING TO
       ANSI C, BSD 4.3

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



GNU				  1993-04-04			   TOUPPER(3)