diff options
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/coreutils.texi | 164 |
1 files changed, 2 insertions, 162 deletions
diff --git a/doc/coreutils.texi b/doc/coreutils.texi index 767267bf3..f7251b29a 100644 --- a/doc/coreutils.texi +++ b/doc/coreutils.texi @@ -109,7 +109,6 @@ * stat: (coreutils)stat invocation. Report file(system) status. * stdbuf: (coreutils)stdbuf invocation. Modify stdio buffering. * stty: (coreutils)stty invocation. Print/change terminal settings. -* su: (coreutils)su invocation. Modify user and group ID. * sum: (coreutils)sum invocation. Print traditional checksum. * sync: (coreutils)sync invocation. Synchronize memory and disk. * tac: (coreutils)tac invocation. Reverse files. @@ -200,7 +199,7 @@ Free Documentation License''. * User information:: id logname whoami groups users who * System context:: date arch nproc uname hostname hostid uptime * SELinux context:: chcon runcon -* Modified command invocation:: chroot env nice nohup stdbuf su timeout +* Modified command invocation:: chroot env nice nohup stdbuf timeout * Process control:: kill * Delaying:: sleep * Numeric operations:: factor seq @@ -443,7 +442,6 @@ Modified command invocation * nice invocation:: Run a command with modified niceness * nohup invocation:: Run a command immune to hangups * stdbuf invocation:: Run a command with modified I/O buffering -* su invocation:: Run a command with substitute user and group ID * timeout invocation:: Run a command with a time limit Process control @@ -766,7 +764,7 @@ meanings with the values @samp{0} and @samp{1}. Here are some of the exceptions: @command{chroot}, @command{env}, @command{expr}, @command{nice}, @command{nohup}, @command{printenv}, @command{sort}, @command{stdbuf}, -@command{su}, @command{test}, @command{timeout}, @command{tty}. +@command{test}, @command{timeout}, @command{tty}. @node Backup options @@ -15266,7 +15264,6 @@ user, etc. * nice invocation:: Modify niceness. * nohup invocation:: Immunize to hangups. * stdbuf invocation:: Modify buffering of standard streams. -* su invocation:: Modify user and group ID. * timeout invocation:: Run with time limit. @end menu @@ -15794,163 +15791,6 @@ the exit status of @var{command} otherwise @end display -@node su invocation -@section @command{su}: Run a command with substitute user and group ID - -@pindex su -@cindex substitute user and group IDs -@cindex user ID, switching -@cindex super-user, becoming -@cindex root, becoming - -@command{su} allows one user to temporarily become another user. It runs a -command (often an interactive shell) with the real and effective user -ID, group ID, and supplemental groups of a given @var{user}. Synopsis: - -@example -su [@var{option}]@dots{} [@var{user} [@var{arg}]@dots{}] -@end example - -@cindex passwd entry, and @command{su} shell -@flindex /bin/sh -@flindex /etc/passwd -If no @var{user} is given, the default is @code{root}, the super-user. -The shell to use is taken from @var{user}'s @code{passwd} entry, or -@file{/bin/sh} if none is specified there. If @var{user} has a -password, @command{su} prompts for the password unless run by a user with -effective user ID of zero (the super-user). - -@vindex HOME -@vindex SHELL -@vindex USER -@vindex LOGNAME -@cindex login shell -By default, @command{su} does not change the current directory. -It sets the environment variables @env{HOME} and @env{SHELL} -from the password entry for @var{user}, and if @var{user} is not -the super-user, sets @env{USER} and @env{LOGNAME} to @var{user}. -By default, the shell is not a login shell. - -Any additional @var{arg}s are passed as additional arguments to the -shell. - -@cindex @option{-su} -GNU @command{su} does not treat @file{/bin/sh} or any other shells specially -(e.g., by setting @code{argv[0]} to @option{-su}, passing @option{-c} only -to certain shells, etc.). - -@findex syslog -@command{su} can optionally be compiled to use @code{syslog} to report -failed, and optionally successful, @command{su} attempts. (If the system -supports @code{syslog}.) However, GNU @command{su} does not check if the -user is a member of the @code{wheel} group; see below. - -The program accepts the following options. Also see @ref{Common options}. - -@table @samp -@item -c @var{command} -@itemx --command=@var{command} -@opindex -c -@opindex --command -Pass @var{command}, a single command line to run, to the shell with -a @option{-c} option instead of starting an interactive shell. - -@item -f -@itemx --fast -@opindex -f -@opindex --fast -@flindex .cshrc -@cindex file name pattern expansion, disabled -@cindex globbing, disabled -Pass the @option{-f} option to the shell. This probably only makes sense -if the shell run is @command{csh} or @command{tcsh}, for which the @option{-f} -option prevents reading the startup file (@file{.cshrc}). With -Bourne-like shells, the @option{-f} option disables file name pattern -expansion (globbing), which is not likely to be useful. - -@item - -@itemx -l -@itemx --login -@opindex - -@opindex -l -@opindex --login -@c other variables already indexed above -@vindex TERM -@vindex PATH -@cindex login shell, creating -Make the shell a login shell. This means the following. Unset all -environment variables except @env{TERM}, @env{HOME}, and @env{SHELL} -(which are set as described above), and @env{USER} and @env{LOGNAME} -(which are set, even for the super-user, as described above), and set -@env{PATH} to a compiled-in default value. Change to @var{user}'s home -directory. Prepend @samp{-} to the shell's name, intended to make it -read its login startup file(s). - -@item -m -@itemx -p -@itemx --preserve-environment -@opindex -m -@opindex -p -@opindex --preserve-environment -@cindex environment, preserving -@flindex /etc/shells -@cindex restricted shell -Do not change the environment variables @env{HOME}, @env{USER}, -@env{LOGNAME}, or @env{SHELL}. Run the shell given in the environment -variable @env{SHELL} instead of the shell from @var{user}'s passwd -entry, unless the user running @command{su} is not the super-user and -@var{user}'s shell is restricted. A @dfn{restricted shell} is one that -is not listed in the file @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 @option{--login} and @option{--shell}. - -@item -s @var{shell} -@itemx --shell=@var{shell} -@opindex -s -@opindex --shell -Run @var{shell} instead of the shell from @var{user}'s passwd entry, -unless the user running @command{su} is not the super-user and @var{user}'s -shell is restricted (see @option{-m} just above). - -@end table - -@cindex exit status of @command{su} -Exit status: - -@display -125 if @command{su} itself fails -126 if subshell is found but cannot be invoked -127 if subshell cannot be found -the exit status of the subshell otherwise -@end display - -@cindex wheel group, not supported -@cindex group wheel, not supported -@cindex fascism -@subsection Why GNU @command{su} does not support the @samp{wheel} group - -(This section is by Richard Stallman.) - -@cindex Twenex -@cindex MIT AI lab -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 -@command{su} mechanism, once someone learns the root password who -sympathizes with the ordinary users, he or she can tell the rest. The -``wheel group'' feature would make this impossible, 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. - - @node timeout invocation @section @command{timeout}: Run a command with a time limit |