VHANGUP(2) UNIX Programmer's Manual VHANGUP(2) NNAAMMEE vhangup - virtually ``hangup'' the current control terminal SSYYNNOOPPSSIISS vvhhaanngguupp(()) DDEESSCCRRIIPPTTIIOONN _V_h_a_n_g_u_p is used by the initialization process _i_n_i_t(8) (among others) to arrange that users are given "clean"' terminals at login, by revoking access of the previous users' processes to the terminal. To effect this, _v_h_a_n_g_u_p searches the system tables for references to the control terminal of the invoking process, revoking access permissions on each instance of the terminal that it finds. Further attempts to access the terminal by the affected processes will yield i/o errors (EBADF). Finally, a hangup signal (SIGHUP) is sent to the process group of the control terminal. SSEEEE AALLSSOO init (8) BBUUGGSS Access to the control terminal via //ddeevv//ttttyy is still possi- ble. This call should be replaced by an automatic mechanism that takes place on process exit. Printed 7/9/88 June 30, 1985 1