Open a pseudo-terminal device
Synopsis:
#include <stdlib.h>
#include <fcntl.h>
int posix_openpt( int oflag );
Arguments:
- oflag
- Flags that specify the file status flags and file access modes of the
open file description; a combination of the following:
- O_RDWR — open for reading and writing.
- O_NOCTTY — don't make the terminal device become
the controlling terminal for the process.
Library:
libc
Use the -l c option to
qcc
to link against this library.
This library is usually included automatically.
Note:
This function is in libc.a, but not in libc.so
(in order to save space).
Description:
The posix_openpt() function establishes a connection between
a master device for a pseudo-terminal and a file descriptor.
The file descriptor is used by other I/O functions that refer to that pseudo-terminal.
Returns:
A file descriptor for the master pseudo-terminal, or -1 if an error occurred
(errno
is set).
Errors:
- EMFILE
- All file descriptors available to the process are currently open.
- ENFILE
- The maximum allowable number of files is currently open in the system.
- EINVAL
- The value of oflag isn't valid.
- EAGAIN
- Out of pseudo-terminal resources.
Classification:
POSIX 1003.1 XSI
| Safety: |
|
|---|
| Cancellation point |
Yes |
| Interrupt handler |
No |
| Signal handler |
Yes |
| Thread |
Yes |