Name

toupper - lower case to upper case letter conversion

Library

Standard C Library (libc, -lc)

Synopsis

#include <ctype.h>

int
toupper(int c);

Description

The toupper() function converts a lower-case letter to the corresponding upper-case letter. For single C chars locales (see multibyte(3) ) the value of the argument is representable as an unsigned char or the value of EOF.

Return Values

If the argument is a lower-case letter, the toupper() function returns the corresponding upper-case letter if there is one; otherwise the argument is returned unchanged.

Compatibility

Although toupper() accepts arguments outside of the range of the unsigned char type in locales with large character sets, this is a 4.4BSD extension and the towupper() function should be used instead for maximum portability.

See Also

ctype(3) , isupper(3) , multibyte(3) , towupper(3)

Standards

The toupper() function conforms to ISO/IEC 9899:1990 (``ISO C89'').

Table of Contents

• Name
• Library
• Synopsis
• Description
• Return Values
• Compatibility
• See Also
• Standards