TOUPPER(3) |
FreeBSD Library Functions Manual |
TOUPPER(3) |
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. The argument must be 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
The
4.4BSD extension of accepting arguments outside of the range of the
unsigned char type in locales with large character sets is considered obsolete and may not be supported in future releases. The
towupper() function should be used instead.
STANDARDS
The
toupper() function conforms to ISO/IEC 9899:1990 (“ISO C90”).