ISATTY(3) Linux Programmer's Manual ISATTY(3)NAMEisatty - 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 VALUEisatty() returns 1 if fd is an open file descriptor referring to a ter‐
minal; 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 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 ALSOfstat(2), ttyname(3)COLOPHON
This page is part of release 4.14 of the Linux man-pages project. A
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latest version of this page, can be found at
https://www.kernel.org/doc/man-pages/.
Linux 2015-08-08 ISATTY(3)