isatty() tests if file descriptor is associated with terminal device	Function
	SYNOPSIS DESCRIPTION PARAMETERS RETURN VALUES CONFORMANCE MULTITHREAD SAFETY LEVEL PORTING ISSUES AVAILABILITY SEE ALSO

---

SYNOPSIS

#include <unistd.h>

int isatty(int fildes);

---

DESCRIPTION

The isatty() function tests whether the specified file descriptor is associated with a terminal device.

---

PARAMETERS

fildes 

Is the file descriptor to test.

---

RETURN VALUES

If the file descriptor fildes describes a terminal, isatty() returns a value of 1. If fildes is not a terminal, isatty() returns a value of zero, and sets errno to one of the following values:

ENOTTY 

The fildes parameter is not associated with a terminal.

---

CONFORMANCE

UNIX 98.

---

MULTITHREAD SAFETY LEVEL

MT-Safe.

---

PORTING ISSUES

None.

---

AVAILABILITY

PTC MKS Toolkit for Professional Developers
PTC MKS Toolkit for Professional Developers 64-Bit Edition
PTC MKS Toolkit for Enterprise Developers
PTC MKS Toolkit for Enterprise Developers 64-Bit Edition

---

SEE ALSO

Functions:

ttyname(), ttyname_r()

---

PTC MKS Toolkit 10.4 Documentation Build 39.