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 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.COLOPHON
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