Zilog Z8F0130 - Manual (Page 441)

UM013037-1212 Character Handling
Zilog Developer Studio II – Z8 Encore!
User Manual
417
macro puts diagnostics into programs. When it is executed, if expression is false (that
is, evaluates to zero), the assert macro writes information about the particular call that
failed (including the text of the argument, the name of the source file, and the source line
number – the latter are respectively the values of the preprocessing macros
__FILE__ and
__LINE__ ) on the serial port. It then calls abort() , which calls exit() . If expression
is true (that is, evaluates to nonzero), the assert macro returns no value.
On Release builds (strictly speaking, when NDEBUG is defined on the compile line), the
assert macro has no effect.
Example
#include

char str[] = "COMPASS";

int main(void)

{

assert(str[0] == 'C'); // OK, nothing happens

assert(str[0] == 'B'); // Oops, something wrong here

return 0;

}
Character Handling
The < ctype.h > header declares several macros and functions useful for testing and map-
ping characters. In all cases, the argument is an int , the value of which is represented as
an unsigned char or equals the value of the EOF macro. If the argument has any other
value, the behavior is undefined.
Macros
Functions
The functions in this section return nonzero (true) if, and only if, the value of the argument
c conforms to that in the description of the function. The term printing character refers to
a member of a set of characters, each of which occupies one printing position on a display
device. The term control character refers to a member of a set of characters that are not
printing characters.
Character Testing
TRUE Expands to a constant 1.
FALSE Expands to a constant 0.
int isalnum(int c); Tests for alphanumeric character.
int isalpha(int c); Tests for alphabetic character.