2. EL 8
  3. man-pages
  4. isatty(3)

Scroll to navigation

ISATTY(3) Linux Programmer's Manual ISATTY(3)

NAME

isatty - test whether a file descriptor refers to a terminal

SYNOPSIS

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

DESCRIPTION

The isatty() function tests whether fd is an open file descriptor referring to a terminal.

RETURN VALUE

isatty() returns 1 if fd is an open file descriptor referring to a terminal; otherwise 0 is returned, and errno is set to indicate the error.

ERRORS

fd is not a valid file descriptor.
fd refers to a file other than a terminal. POSIX.1 specifies the error ENOTTY for this case.

ATTRIBUTES

For an explanation of the terms used in this section, see attributes(7).

Interface Attribute Value
isatty () Thread safety MT-Safe

CONFORMING TO

POSIX.1-2001, POSIX.1-2008, SVr4, 4.3BSD.

SEE ALSO

fstat(2), ttyname(3)

COLOPHON

This page is part of release 4.15 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.

2015-08-08 Linux