isupper3
Upper-case character test
Usage
#include <ctype.h>
int
isupper(int c);
Library
Standard C Library (libc, -lc)
Overview
The isupper() function tests for any upper-case letter. The value of the argument must be representable as an unsigned char or the value of EOF.
In the ASCII character set, this includes the following characters (preceded by their numeric values, in octal):
| 101 ``A'' 102 ``B'' 103 ``C'' 104 ``D'' 105 ``E'' |
| 106 ``F'' 107 ``G'' 110 ``H'' 111 ``I'' 112 ``J'' |
| 113 ``K'' 114 ``L'' 115 ``M'' 116 ``N'' 117 ``O'' |
| 120 ``P'' 121 ``Q'' 122 ``R'' 123 ``S'' 124 ``T'' |
| 125 ``U'' 126 ``V'' 127 ``W'' 130 ``X'' 131 ``Y'' |
| 132 ``Z'' |
Return values
The isupper() function returns zero if the character tests false and returns non-zero if the character tests true.
Compatibility
The 4.4BSD extension of accepting arguments outside of the range of the unsigned char type in locales with large character sets is considered obsolete and may not be supported in future releases. The iswupper() function should be used instead.
Releases
163 releases since Mac OS X 10.0; the text changed 5 times.