isascii : ASCII character predicate

Synopsis

#include <ctype.h>
int isascii(int c);
```### Description

isascii is a macro which returns non-zero when c is an ASCII character, and 0 otherwise. It is defined for all integer values.

You can use a compiled subroutine instead of the macro definition by undefining the macro using `#undef isascii'.### Returns

isascii returns non-zero if the low order byte of c is in the range 0 to 127 (0x00--0x7F).

---

**Authoritative source**: BUSMASTER DITA help source `isascii.dita`, compiled into `BUSMASTER.CHM` with the application.