HP 3000 Manuals

MPE/iX Developer's Kit Reference Manual Volume I

isatty 

Determines whether or not an open file descriptor is associated with a
terminal.

Syntax 

     #include <unistd.h>
     int isatty (int fildes);

Parameters 

fildes     An open file descriptor.

Return Values 

1          The specified file descriptor is associated with a terminal.

0          The specified file descriptor is not associated with a
           terminal.

-1         The specified file descriptor is invalid, and errno is set to
           indicate the error condition.

Description 

The isatty() function returns a value indicating whether or not the open
file descriptor fildes is associated with a terminal.

Implementation Considerations 

Refer to the EBADF error description below.

Errors 

If an error occurs, errno is set to the following value:

EBADF             CAUSE           The fildes parameter is not a valid open file
                                  descriptor.
                  ACTION          Check to see if fildes has been altered or not
                                  initialized.

See Also 

POSIX.1 (Section 4.7.2)

MPE/iX 5.0 Documentation