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 lower-case letter, the result is the corresponding upper-case letter. If the argument of tolower() represents an upper-case letter, the result is the corresponding lower-case 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 lower-case letter as its argument; its result is the corresponding upper-case letter. _tolower() requires an upper-case letter as its argument; its result is the corresponding lower-case 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(), f4_toupper(), and f4_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.
SEE ALSO
ctype(3C), getc(3S), setlocale(3C), environ(5)
SunOS 5.1/SPARC — Last change: 13 Jul 1990