CONV(S) XENIX System V CONV(S)
Name
conv, toupper, tolower, toascii - Translates characters.
Syntax
#include <ctype.h>
int toupper (c)
int c;
int tolower (c)
int c;
int _toupper (c)
int c;
int _tolower (c)
int c;
int toascii (c)
int c;
Description
toupper and tolower convert the argument c to a letter of
opposite case. Arguments may be the integers -1 through 255
(the same values returned by getc(S)). 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 are
returned unchanged.
_toupper and _tolower are macros that accomplish the same
thing as toupper and tolower but have restricted argument
values 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.
All other arguments cause unpredictable results.
toascii converts integer values to ASCII characters. The
function clears all bits of the integer that are not part of
a standard ASCII character; it is intended for compatibility
with other systems.
See Also
ctype(S)
Notes
Because _toupper and _tolower are implemented as macros,
they should not be used where unwanted side effects may
occur. Removing the _toupper and _tolower macros with the
#undef directive causes the corresponding library functions
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CONV(S) XENIX System V CONV(S)
to be linked instead. This allows any arguments to be used
without worry about side effects.
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