NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | ATTRIBUTES | CONFORMING TO | SEE ALSO | COLOPHON

ISATTY(3)                 Linux Programmer's Manual                ISATTY(3)

NAME         top

       isatty - test whether a file descriptor refers to a terminal

SYNOPSIS         top

       #include <unistd.h>

       int isatty(int fd);

DESCRIPTION         top

       The isatty() function tests whether fd is an open file descriptor
       referring to a terminal.

RETURN VALUE         top

       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         top

       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         top

   Multithreading (see pthreads(7))
       The isatty() function is thread-safe.

CONFORMING TO         top

       SVr4, 4.3BSD, POSIX.1-2001.

SEE ALSO         top

       fstat(2), ttyname(3)

COLOPHON         top

       This page is part of release 3.64 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                            2014-01-27                        ISATTY(3)