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.

CONFORMING TO
       SVr4, 4.3BSD, POSIX.1-2001.

SEE ALSO
       fstat(2), ttyname(3)

COLOPHON
       This page is part of release 3.25 of the Linux man-pages project.  A description of the project,  and  information  about
       reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.



Linux                                                      2008-12-03                                                  ISATTY(3)