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/.



Linux                                       2014-01-27                                  ISATTY(3)