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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

EBADF
fd is not a valid file descriptor.
EINVAL
fd refers to a file other than a terminal. POSIX.1-2001 specifies the error ENOTTY for this case.

ATTRIBUTES

Multithreading (see pthreads(7))

The isatty() function is thread-safe.

CONFORMING TO

SVr4, 4.3BSD, POSIX.1-2001.

SEE ALSO

fstat(2), ttyname(3)

COLOPHON

This page is part of release 3.74 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 http://www.kernel.org/doc/man-pages/.
2014-01-27 Linux