projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 3abac3ab C |
1 | .TH VHANGUP 2 "12 Febuary 1983" |
| 2 | .UC 4 | |
| 3 | .SH NAME | |
| 4 | vhangup \- virtually ``hangup'' the current control terminal | |
| 5 | .SH SYNOPSIS | |
| 6 | .B vhangup() | |
| 7 | .SH DESCRIPTION | |
| 8 | .I Vhangup | |
| 9 | is used by the initialization process | |
| 10 | .IR init (8) | |
| 11 | (among others) to arrange that users are given | |
| 12 | \*(lqclean\*(rq' terminals at login, | |
| 13 | by revoking access of the previous users' processes to the terminal. | |
| 14 | To effect this, | |
| 15 | .I vhangup | |
| 16 | searches the system tables for references to the control terminal | |
| 17 | of the invoking process, revoking access permissions | |
| 18 | on each instance of the terminal which it finds. | |
| 19 | Further attempts to access the terminal by the affected processes | |
| 20 | will yield i/o errors (EBADF). | |
| 21 | Finally, | |
| 22 | a hangup signal (SIGHUP) is sent to the process group of the | |
| 23 | control terminal. | |
| 24 | .SH SEE ALSO | |
| 25 | init (8) | |
| 26 | .SH BUGS | |
| 27 | Access to | |
| 28 | the control terminal via | |
| 29 | .B /dev/tty | |
| 30 | is still possible. | |
| 31 | .PP | |
| 32 | This call should be replaced by an automatic mechanism which | |
| 33 | takes place on process exit. |