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- /xlv1/freeware/1998.May/sh-utils/1.16b/sh-utils-1.16b.diffbuild/man
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- NNNNAAAAMMMMEEEE
- su - run a shell with substitute user and group IDs
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- SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSS
- ssssuuuu [-flmp] [-c command] [-s shell] [--login] [--fast]
- [--preserve-environment] [--command=command] [--shell=shell]
- [-] [--help] [--version] [user [arg...]]
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- DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
- This documentation is no longer being maintained and may be
- inaccurate or incomplete. The Texinfo documentation is now
- the authoritative source.
-
- This manual page documents the GNU version of ssssuuuu. ssssuuuu allows
- one user to temporarily become another user. It runs a
- shell with the real and effective user ID, group ID, and
- supplemental groups of USER. If no USER is given, the
- default is root, the super-user. The shell run is taken
- from USER's password entry, or /bin/sh if none is specified
- there. If USER has a password, ssssuuuu prompts for the password
- unless run by a user with real user ID 0 (the super-user).
-
- By default, ssssuuuu does not change the current directory. It
- sets the environment variables `HOME' and `SHELL' from the
- password entry for USER, and if USER is not the super-user,
- sets `USER' and `LOGNAME' to USER. By default, the shell is
- not a login shell.
-
- If one or more ARGs are given, they are passed as additional
- arguments to the shell.
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- ssssuuuu does not handle /bin/sh or other shells specially
- (setting argv[0] to "-su", passing -c only to certain
- shells, etc.).
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- On systems that have syslog, ssssuuuu can be compiled to report
- failed, and optionally successful, ssssuuuu attempts using syslog.
-
- This program does not support a "wheel group" that restricts
- who can ssssuuuu to super-user accounts, because that can help
- fascist system administrators hold unwarranted power over
- other users.
-
- OOOOPPPPTTTTIIIIOOOONNNNSSSS
- -_c _C_O_M_M_A_N_D, --_c_o_m_m_a_n_d=_C_O_M_M_A_N_D
- Pass COMMAND, a single command line to run, to the
- shell with a -_c option instead of starting an
- interactive shell.
-
- -_f, --_f_a_s_t
- Pass the -_f option to the shell. This probably only
- makes sense with ccccsssshhhh and ttttccccsssshhhh, for which the -_f option
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- Page 1 (printed 5/18/98)
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- SSSSUUUU((((1111)))) FFFFSSSSFFFF ((((GGGGNNNNUUUU SSSShhhheeeellllllll UUUUttttiiiilllliiiittttiiiieeeessss)))) SSSSUUUU((((1111))))
-
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- prevents reading the startup file (.cshrc). With
- Bourne-like shells, the -_f option disables filename
- pattern expansion, which is not a generally desirable
- thing to do.
-
- --_h_e_l_p
- Print a usage message on standard output and exit
- successfully.
-
- -, -_l, --_l_o_g_i_n
- Make the shell a login shell. This means the
- following. Unset all environment variables except
- `TERM', `HOME', and `SHELL' (which are set as described
- above), and `USER' and `LOGNAME' (which are set, even
- for the super-user, as described above), and set `PATH'
- to a compiled-in default value. Change to USER's home
- directory. Prepend "-" to the shell's name, to make it
- read its login startup file(s).
-
- -_m, -_p, --_p_r_e_s_e_r_v_e-_e_n_v_i_r_o_n_m_e_n_t
- Do not change the environment variables `HOME', `USER',
- `LOGNAME', or `SHELL'. Run the shell given in the
- environment variable `SHELL' instead of USER's shell
- from /etc/passwd, unless the user running ssssuuuu is not the
- superuser and USER's shell is restricted. A restricted
- shell is one that is not listed in the file
- /etc/shells, or in a compiled-in list if that file does
- not exist. Parts of what this option does can be
- overridden by --_l_o_g_i_n and --_s_h_e_l_l.
-
- -_s, --_s_h_e_l_l _s_h_e_l_l
- Run SHELL instead of USER's shell from /etc/passwd,
- unless the user running ssssuuuu is not the superuser and
- USER's shell is restricted.
-
- --_v_e_r_s_i_o_n
- Print version information on standard output then exit
- successfully.
-
- WWWWhhhhyyyy GGGGNNNNUUUU ssssuuuu ddddooooeeeessss nnnnooootttt ssssuuuuppppppppoooorrrrtttt
- Sometimes a few of the users try to hold total power over
- all the rest. For example, in 1984, a few users at the MIT
- AI lab decided to seize power by changing the operator
- password on the Twenex system and keeping it secret from
- everyone else. (I was able to thwart this coup and give
- power back to the users by patching the kernel, but I
- wouldn't know how to do that in Unix.)
-
- However, occasionally the rulers do tell someone. Under the
- usual su mechanism, once someone learns the root password
- who sympathizes with the ordinary users, he can tell the
- rest. The "wheel group" feature would make this impossible,
-
-
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- Page 2 (printed 5/18/98)
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-
- and thus cement the power of the rulers.
-
- I'm on the side of the masses, not that of the rulers. If
- you are used to supporting the bosses and sysadmins in
- whatever they do, you might find this idea strange at first.
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- Page 3 (printed 5/18/98)
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