HP C/iX Library Reference Manual (30026-90004)

224 Chapter5
HP C/iX Library Function Descriptions
isupper
isupper
Tests whether an argument is an uppercase letter.
Syntax
#include <ctype.h>
int isupper (int c );
Parameters
c An argument to be evaluated. The argument must be representable as an
unsigned char or the macro EOF.
Return Values
≠0 The argument passed in c is an uppercase letter.
0 The argument passed in
c is not an uppercase letter.
Description
The isupper function returns a nonzero value if the argument passed in c is an uppercase
letter (ASCII characters A through Z); otherwise, the returned value is zero.
See Also
isalnum, isalpha, iscntrl, isdigit, isgraph, islower, isprint, ispunct, isspace,
isxdigit. ANSI C 4.3.1.10, POSIX.1 8.1