conv(3C) conv(3C)
NAME
conv: toupper, tolower, _toupper, _tolower, toascii -
translate characters
SYNOPSIS
#include <ctype.h>
int toupper(int c);
int tolower(int c);
int _toupper(int c);
int _tolower(int c);
int toascii(int c);
DESCRIPTION
toupper and tolower have as their domain the range of the
function getc: all values represented in an unsigned char and
the value of the macro EOF as defined in stdio.h. If the
argument of toupper represents a lowercase letter, the result
is the corresponding uppercase letter. If the argument of
tolower represents an uppercase letter, the result is the
corresponding lowercase letter. All other arguments in the
domain are returned unchanged.
The macros _toupper and _tolower accomplish the same things as
toupper and tolower, respectively, but have restricted domains
and are faster. _toupper requires a lowercase letter as its
argument; its result is the corresponding uppercase letter.
_tolower requires an uppercase letter as its argument; its
result is the corresponding lowercase letter. Arguments
outside the domain cause undefined results.
toascii yields its argument with all bits turned off that are
not part of a standard 7-bit ASCII character; it is intended
for compatibility with other systems.
toupper, tolower, _toupper, and_tolower are affected by
LC_CTYPE. In the C locale, or in a locale where shift
information is not defined, these functions determine the case
of characters according to the rules of the ASCII-coded
character set. Characters outside the ASCII range of
characters are returned unchanged.
All the conversion functions and macros use a table lookup.
REFERENCES
ctype(3C), environ(5), getc(3S), setlocale(3C), wconv(3C)
Copyright 1994 Novell, Inc. Page 1