NAME
toupper —
transliterate lowercase characters to uppercase
SYNOPSIS
#include
<ctype.h>
int toupper(int c);
DESCRIPTION
[CX] The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of IEEE Std 1003.1-2001 (“POSIX.1”) defers to the ISO C standard.
The toupper () function has as a
domain a type int,
the value of which is representable as an
unsigned
char or the value of EOF. If the argument has any other value, the
behavior is undefined. If the argument of toupper ()
represents a lowercase letter, and there exists a corresponding uppercase
letter [CX] (as defined by character type information in
the program locale category
LC_CTYPE
), the result shall be the corresponding uppercase letter. All other
arguments in the domain are returned unchanged.
RETURN VALUE
Upon successful completion, toupper ()
shall return the uppercase letter corresponding to the argument passed.
ERRORS
No errors are defined.
EXAMPLES
None.
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
setlocale(3), the Base Definitions volume of IEEE Std 1003.1-2001 (“POSIX.1”), xbd_chap07(7), <ctype.h>
CHANGE HISTORY
First released in Issue 1. Derived from Issue 1 of the SVID.
Issue 6
Extensions beyond the ISO C standard are marked.
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