isatty

Syntax

#include <unistd.h> int isatty(int fd);

Description

Tells if the file descriptor refers to a terminal device or not.

Return Value

Nonzero if fd is a terminal device, zero otherwise.

Portability

ANSI/ISO C	No
POSIX	1003.2-1992; 1003.1-2001

Example

if (isatty(1)) fflush(stdout);