| tabs | Index Level | tape-socket |
| Syntax | tandem port.number {(options} |
| Category | TCL |
| Type | Verb |
| Description |
links the current port to another process. Any input or output to either screen affects both screens.
The port initiating the "tandem" command is the "master". The process being attached is the "slave" or "target". If the slave process is a "phantom" process, the output from the phantom is redirected to the master. The target device (the one attached to the slave) must be available on the given port. It may not be already attached to another process. A "hotkey" sequence disconnects the link. The default "hotkey" sequence is <escape>x. If an "esc-data" has not been issued previously, the process issues it automatically, to prevent getting locked out from being able to suspend "tandem". See the "trap" command for handling output message handling. (e.g. turning off the "TANDEM STARTED" message.) |
| Options |
d Designates the sequence of (up to four) characters to terminate "tandem" mode. Each character is provided in its hexadecimal equivalent of its ASCII value. Each character is separated by a comma. For example, "d/41,42,43,44", indicates that an "ABCD" will disconnect the link. The first two characters of the termination sequence must be different. For instance, it will NOT accept "d/2b,2b,2b" (+++), but it will accept "d/2a,2b,2b" (*++).
f Turns off the ability to tandem on the current port. This keeps others from being able to tandem the current port. On release 6.1 and later, specifying "port.number" allows turning off tandem on another port, if the user has a SYS2 privilege. n Turns on the ability to tandem on the current port. This gives others the ability to tandem the current port. May NOT be used with the "u" option. On D3, specifying "port.number" allows turning on tandem on another port, if the user has a SYS2 privilege. s Suppresses the message when the process terminates. If this is used with the "d" option, the "s" option must precede the "d" option. u Unconditionally turns off tandem when used with the "f" option. x Terminates tandem mode on target device number. y Set the 'Notify' option. Available only on releases 6.1 and above. When tandem is started or terminated on the process, the command specified for the 'tdmon' or 'tdmof' signals in the TCL "trap" command. |
| See Also | converse mirror port.number system privileges devs me dev-att link-pibdev :reset-async dev-det trap :ent-mon list-tandems |
| Example |
tandem 13
Attaches the current process to port 13. tandem 33 (d/2a,2b,2b Attaches to port 3 and sets the hotkey sequence to "*++". tandem (n Enables ability to be "tandemed" on the current port. tandem 42 (uf Unconditionally disables "tandem" capability on port 42. tandem 13 (x Terminates tandem on port 13. tcl 42 bob tandem (n tandem 42 The "tcl" command can be used to enable tandem on another port. |
| Warnings |
If the "master" and "slave" processes are different types of CRT's, or are using different emulations or term types, the output to the "master" screen may be garbled.
If the current task has "esc-level" in effect, "tandem" automatically issues an "esc-data", so that it can be terminated by "<escape>x". It does NOT, however, reset the "esc-level" upon termination -- it must be manually re-executed to restore to its previous state. When a process pushes a shell to Unix while being tandemed by another port, theoretically, the Pick process is suspended by Unix, therefore the input from the master will not be processed by the Pick process until it is re-activated by Unix. On releases prior to 6.1, the "n" and "f" options can only be performed on the current terminal, even if a "port.number" is specified. On versions prior to 6.1, if a phantom process attempts to do an input, the process is de-activated and stays until it is logged off. On D3, a phantom doing an input will stay at input. Another process can then use tandem to feed data to the phantom, to allow it to continue. |
| Compatibility | D3 7.0 AP AP 6.1 |
| tabs | Index Level | tape-socket |