HP C/iX Library Reference Manual (30026-90004)
Chapter 5 371
HP C/iX Library Function Descriptions
toupper, _toupper
toupper, _toupper
Converts a lowercase letter to uppercase.
Syntax
#include <ctype.h>
int toupper (int
c
);
Parameters
c
An argument to be converted to uppercase.
Return Values
x The uppercase letter that corresponds with
c
.If
c
is not a lowercase letter
and the function is called,
c
is returned unchanged. If
c
is not a lowercase
letter and the macro is called, the results are undefined.
Description
This conversion routine that upshifts ASCII characters is implemented both as a function
and as a macro. The toupper function and _toupper macro have a domain the range of
getc() (the integers from -1 through 255). If the argument passed in
c
represents an
lowercase letter, toupper() returns the corresponding uppercase letter. All other
arguments in the domain are returned unchanged.
The _toupper macro accomplishes the same thing as the function, but has a restricted
domain and is faster. The _toupper macro requires a lowercase letter as its argument.
Arguments outside the domain cause undefined results.
NOTE
The toupper function and macro do not work with foreign character sets.
Examples
The following code fragment might appear in the scanner of a case-insensitive compiler,
where all source input is mapped to uppercase before any processing is performed.
unsigned char *ps;
while (*ps != '\0'){
*ps = toupper(*ps);
&+&+ps;
}
See Also
tolower(), ANSI C 4.3.2.2, POSIX.1 8.1