.\" Copyright (c) 2009 Renzo Davoli
.\"
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.TH VIEW-OS 1 "August 5, 2009" "VIEW-OS: a process with a view"
.SH NAME
viewsu \- change (virtual) user ID or become (virtual) superuser
.SH "SYNOPSIS"
.HP \w'\fBviewsu\fR\ 'u
\fBviewsu\fR [\fIoptions\fR] [\fIusername\fR]
.SH "DESCRIPTION"
.PP
The
\fBviewsu\fR
command is used to become another user during a login session\&. Invoked without a
\fBusername\fR,
\fBviewsu\fR
defaults to becoming the superuser\&. The optional argument
\fB\-\fR
may be used to provide an environment similar to what the user would expect had the user logged in directly\&.
This command is the View-OS counterpart of the su(1) command.
The value of
\fB$PATH\fR
is reset to
/bin:/usr/bin
for normal users, or
/sbin:/bin:/usr/sbin:/usr/bin
for the superuser\&. This may be changed with the
\fIENV_PATH\fR
and
\fIENV_SUPATH\fR
definitions in
/etc/login\&.defs\&.
.SH OPTIONS
.PP
The options which apply to the
\fBviewsu\fR
command are:
.PP
\fB\-c\fR, \fB\-\-command\fR \fICOMMAND\fR
.RS 4
Specify a command that will be invoked by the shell using its
\fB\-c\fR\&.
.RE
.PP
\fB\-\fR, \fB\-l\fR, \fB\-\-login\fR
.RS 4
Provide an environment similar to what the user would expect had the user logged in directly\&.
.sp
When
\fB\-\fR
is used, it must be specified as the last
\fBviewsu\fR
option\&. The other forms (\fB\-l\fR
and
\fB\-\-login\fR) do not have this restriction\&.
.RE
.PP
\fB\-s\fR, \fB\-\-shell\fR \fISHELL\fR
.RS 4
The shell that will be invoked\&.
.sp
The invoked shell is chosen from (highest priority first):
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
The shell specified with \-\-shell\&.
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.\" .el \{\
.\" .sp -1
.\" .IP \(bu 2.3
.\" .\}
.\" If
.\" \fB\-\-preserve\-environment\fR
.\" is used, the shell specified by the
.\" \fB$SHELL\fR
.\" environment variable\&.
.\" .RE
.\" .sp
.\" .RS 4
.\" .ie n \{\
.\" \h'-04'\(bu\h'+03'\c
.\" .\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
The shell indicated in the
/etc/passwd
entry for the target user\&.
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}

/bin/sh
if a shell could not be found by any above method\&.
.RE
.RS 4

.SH SEE ALSO
.BR su(1),
.BR linux.defs(5)
.SH AUTHORS
View-OS is a project of the Computer Science Department, University of
Bologna. Project Leader: Renzo Davoli.
.br
<http://www.sourceforge.net/projects/view-os>

Howto's and further information can be found on the project wiki
<wiki.virtualsquare.org>.
.SH NOTE
Most part of the text is taken from su(1).