ptmx(M)

ptmx, pts??? -- STREAMS master pseudo-tty device

Description

The file /dev/ptmx is the device node used by applications to open STREAMS-based master pseudo-tty devices. This is a single device node which allows access to multiple devices via the clone(M) driver. Successive open(S) calls to /dev/ptmx return different file descriptors, each referring to a new cloned device.

The master pseudo-tty device opened is used to transfer data between the application and one of the slave pseudo-tty nodes /dev/pts???, where ??? is a 3 digit decimal number with leading zeros.

Limitations

Although /dev/ptmx is referred to as a pseudo-tty, the master device does not have tty characteristics and therefore cannot become the controlling tty of a process group. The slave side of the connection does have the characteristics of a real tty and can become the controlling tty of a process group.

Files

/dev/ptmx
/dev/pts???

ptmx(M)

Description

Limitations

Files

See also