isatty()

Test to see if a file descriptor is associated with a terminal

Synopsis:

#include <unistd.h>

int isatty( int filedes );

Arguments:

filedes
The file descriptor that you want to test.

Library:

libc

Use the -l c option to qcc to link against this library. This library is usually included automatically.

Description:

The isatty() function allows the calling process to determine if the file descriptor filedes is associated with a terminal.

Returns:

0
The filedes file descriptor doesn't refer to a terminal.
1
The filedes file descriptor refers to a terminal.

Examples:

/*
 * The following program exits with a status of
 * EXIT_SUCCESS if stderr is a tty; otherwise,
 * EXIT_FAILURE
 */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

int main( void )
{
    return( isatty( STDERR_FILENO ) ? EXIT_SUCCESS : EXIT_FAILURE );
}

Classification:

POSIX 1003.1

Safety:  
Cancellation point No
Interrupt handler No
Signal handler No
Thread Yes