Manpages - isatty.3
Table of Contents
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.
- ENOTTY
- fd refers to a file other than a terminal. On some older kernels, some types of files resulted in the error EINVAL in this case (which is a violation of POSIX, which specifies the error ENOTTY).
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
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