SU(1) UNIX Programmer's Manual SU(1) NNAAMMEE su - substitute user id SSYYNNOOPPSSIISS ssuu [[ --KKffllmm ]] [[ llooggiinn ]] DDEESSCCRRIIPPTTIIOONN _S_u requests the Kerberos password for _l_o_g_i_n (or for ``_l_o_g_i_n.root'', if no login is provided), and switches to that user and group ID after obtaining a Kerberos ticket granting ticket. A shell is then invoked. _S_u will resort to the local password file to find the password for _l_o_g_i_n if there is a Kerberos error. If _s_u is executed by root, no password is requested and a shell with the appropriate user ID is invoked; no additional Kerberos tickets are obtained. By default, the environment is unmodified with the exception of _U_S_E_R, _H_O_M_E, and _S_H_E_L_L. _H_O_M_E and _S_H_E_L_L are set to the target login's default values. _U_S_E_R is set to the target login, unless the target login has a user ID of 0, in which case it is unmodified. The invoked shell is the target login's. This is the traditional behavior of _s_u. The options are as follows: -K Do not attempt to use Kerberos to authenticate the user. -f If the invoked shell is _c_s_h(1), this option prevents it from reading the ``.cshrc'' file. -l Simulate a full login. The environment is discarded except for _H_O_M_E, _S_H_E_L_L, _P_A_T_H, _T_E_R_M, and _U_S_E_R. _H_O_M_E and _S_H_E_L_L are modified as above. _U_S_E_R is set to the target login. _P_A_T_H is set to ``/bin:/usr/bin''. _T_E_R_M is imported from your current environment. The invoked shell is the target login's, and _s_u will change direc- tory to the target login's home directory. -m Leave the environment unmodified. The invoked shell is your login shell, and no directory changes are made. As a security precaution, if the target user's shell is a non-standard shell (as defined by _g_e_t_u_s_e_r_s_h_e_l_l(3)) and the caller's real uid is non-zero, _s_u will fail. The -l and -m options are mutually exclusive; the last one specified overrides any previous ones. Only users in group 0 (normally ``wheel'') can _s_u to ``root''. Printed 7/27/90 1Q 1 SU(1) UNIX Programmer's Manual SU(1) By default (unless the prompt is reset by a startup file) the super-user prompt is set to ``#'' to remind one of its awesome power. SSEEEE AALLSSOO csh(1), login(1), sh(1), kinit(1), kerberos(1), passwd(5), group(5), environ(7) Printed 7/27/90 2Q 2