HP OpenVMS Systems Documentation

HP OpenVMS DCL Dictionary

Transfers control from your current process (which then hibernates) to the specified process.

The ATTACH and SPAWN commands cannot be used if your terminal has an associated mailbox.

Format

ATTACH [process-name]

Parameter

process-name

Specifies the name of a parent process or spawned subprocess to which control passes. The process must already exist, be part of your current job, and share the same input stream as your current process. However, the process cannot be your current process or a subprocess created with the /NOWAIT qualifier.

Process names can contain from 1 to 15 alphanumeric characters. If a connection to the specified process cannot be made, an error message is displayed.

The process-name parameter is incompatible with the /IDENTIFICATION qualifier.

Description

The ATTACH command allows you to connect your input stream to another process. You can use the ATTACH command to change control from one subprocess to another subprocess or to the parent process.

When you enter the ATTACH command, the parent or "source" process is put into hibernation, and your input stream is connected to the specified destination process. You can use the ATTACH command to connect to a subprocess that is part of a current job left hibernating as a result of the SPAWN/WAIT command or another ATTACH command as long as the connection is valid. (No connection can be made to the current process, to a process that is not part of the current job, or to a process that does not exist. If any of these connections are attempted, an error message is displayed.)

You can also use the ATTACH command in conjunction with the SPAWN/WAIT command to return to a parent process without terminating the created subprocess. See the description of the SPAWN command for more details.

Qualifier

/IDENTIFICATION=pid

Specifies the process identification (PID) of the process to which terminal control will be transferred. Leading zeros can be omitted. The /IDENTIFICATION qualifier is incompatible with the process-name parameter.

If you omit the /IDENTIFICATION qualifier, you must specify a process name.

Examples

$ ATTACH JONES_2
      

The ATTACH command transfers the terminal's control to the subprocess JONES_2.

$ ATTACH/IDENTIFICATION=30019
      

The ATTACH command switches control from the current process to a process having the PID 30019. Notice that because the /IDENTIFICATION qualifier is specified, the process-name parameter is omitted.