---
name: "isascii"
section: "3"
platform: "freebsd"
package: "base"
version: "16.0-CURRENT-20261027-61c70dc16a79"
release: "FreeBSD 16.0-CURRENT (2026-10-27)"
platforms: ["linux", "freebsd", "macos"]
url: "https://new.carta.tech/isascii"
---

# isascii(3)

test for ASCII character

## NAME

**isascii** – test for ASCII character

## LIBRARY

Standard C Library (libc, -lc)

## SYNOPSIS

**#include \<ctype.h\>**

*int*\

**isascii**(*int c*);

## DESCRIPTION

The **isascii**() function tests for an ASCII character, which is any character between 0 and octal 0177 inclusive.

## SEE ALSO

[ctype(3)](/ctype/3.md), [iswascii(3)](/iswascii/3.md), [ascii(7)](/ascii/7.md)

## HISTORY

The **isascii**() function first appeared in Version 7 AT&T UNIX.