rtems-docs/shell/general_commands.rst
2016-05-02 20:51:25 -04:00

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.. COMMENT: COPYRIGHT (c) 1988-2008.
.. COMMENT: On-Line Applications Research Corporation (OAR).
.. COMMENT: All rights reserved.
General Commands
################
Introduction
============
The RTEMS shell has the following general commands:
- help_ - Print command help
- alias_ - Add alias for an existing command
- cmdls_ - List commands
- cmdchown_ - Change user or owner of commands
- cmdchmod_ - Change mode of commands
- date_ - Print or set current date and time
- echo_ - Produce message in a shell script
- sleep_ - Delay for a specified amount of time
- id_ - show uid gid euid and egid
- tty_ - show ttyname
- whoami_ - print effective user id
- getenv_ - print environment variable
- setenv_ - set environment variable
- unsetenv_ - unset environment variable
- time_ - time command execution
- logoff_ - logoff from the system
- rtc_ - RTC driver configuration
- exit_ - alias for logoff command
Commands
========
This section details the General Commands available. A subsection is dedicated
to each of the commands and describes the behavior and configuration of that
command as well as providing an example usage.
.. _help:
help - Print command help
-------------------------
.. index:: help
**SYNOPSYS:**
.. code:: shell
help misc
**DESCRIPTION:**
This command prints the command help. Help without arguments prints a list of
topics and help with a topic prints the help for that topic.
**EXIT STATUS:**
This command returns 0.
**NOTES:**
The help print will break the output up based on the environment variable
SHELL_LINES. If this environment variable is not set the default is 16
lines. If set the number of lines is set to that the value. If the shell lines
is set 0 there will be no break.
**EXAMPLES:**
The following is an example of how to use ``alias``:
.. code:: shell
SHLL [/] $ help
help: ('r' repeat last cmd - 'e' edit last cmd)
TOPIC? The topics are
mem, misc, files, help, rtems, network, monitor
SHLL [/] $ help misc
help: list for the topic 'misc'
alias - alias old new
time - time command [arguments...]
joel - joel [args] SCRIPT
date - date [YYYY-MM-DD HH:MM:SS]
echo - echo [args]
sleep - sleep seconds [nanoseconds]
id - show uid, gid, euid, and egid
tty - show ttyname
whoami - show current user
logoff - logoff from the system
setenv - setenv [var] [string]
getenv - getenv [var]
unsetenv - unsetenv [var]
umask - umask [new_umask]
Press any key to continue...
rtc - real time clock read and set
SHLL [/] $ setenv SHELL_ENV 0
SHLL [/] $ help misc
help: list for the topic 'misc'
alias - alias old new
time - time command [arguments...]
joel - joel [args] SCRIPT
date - date [YYYY-MM-DD HH:MM:SS]
echo - echo [args]
sleep - sleep seconds [nanoseconds]
id - show uid, gid, euid, and egid
tty - show ttyname
whoami - show current user
logoff - logoff from the system
setenv - setenv [var] [string]
getenv - getenv [var]
unsetenv - unsetenv [var]
umask - umask [new_umask]
rtc - real time clock read and set
**CONFIGURATION:**
This command has no configuration.
.. _alias:
alias - add alias for an existing command
-----------------------------------------
.. index:: alias
**SYNOPSYS:**
.. code:: shell
alias oldCommand newCommand
**DESCRIPTION:**
This command adds an alternate name for an existing command to the command set.
**EXIT STATUS:**
This command returns 0 on success and non-zero if an error is encountered.
**NOTES:**
None.
**EXAMPLES:**
The following is an example of how to use ``alias``:
.. code:: shell
SHLL [/] $ me
shell:me command not found
SHLL [/] $ alias whoami me
SHLL [/] $ me
rtems
SHLL [/] $ whoami
rtems
**CONFIGURATION:**
.. index:: CONFIGURE_SHELL_NO_COMMAND_ALIAS
.. index:: CONFIGURE_SHELL_COMMAND_ALIAS
This command is included in the default shell command set. When building a
custom command set, define ``CONFIGURE_SHELL_COMMAND_ALIAS`` to have this
command included.
This command can be excluded from the shell command set by defining
``CONFIGURE_SHELL_NO_COMMAND_ALIAS`` when all shell commands have been
configured.
**PROGRAMMING INFORMATION:**
.. index:: rtems_shell_rtems_main_alias
The ``alias`` is implemented by a C language function which has the following
prototype:
.. code:: c
int rtems_shell_rtems_main_alias(
int argc,
char **argv
);
The configuration structure for the ``alias`` has the following prototype:
.. code:: c
extern rtems_shell_cmd_t rtems_shell_ALIAS_Command;
.. _cmdls:
cmdls - List commands
---------------------
.. index:: cmdls
**SYNOPSYS:**
.. code:: shell
cmdls COMMAND...
**DESCRIPTION:**
This command lists the visible commands of the command set.
**EXIT STATUS:**
This command returns 0 on success and non-zero if an error is encountered.
**NOTES:**
The current user must have read permission to list a command.
**EXAMPLES:**
The following is an example of how to use ``cmdls``:
.. code:: shell
SHLL [/] # cmdls help shutdown
r-xr-xr-x 0 0 help
r-x------ 0 0 shutdown
**CONFIGURATION:**
.. index:: CONFIGURE_SHELL_NO_COMMAND_CMDLS
.. index:: CONFIGURE_SHELL_COMMAND_CMDLS
This command is included in the default shell command set. When building a
custom command set, define ``CONFIGURE_SHELL_COMMAND_CMDLS`` to have this
command included.
This command can be excluded from the shell command set by defining
``CONFIGURE_SHELL_NO_COMMAND_CMDLS`` when all shell commands have been
configured.
**PROGRAMMING INFORMATION:**
The configuration structure for the ``cmdls`` has the following prototype:
.. code:: c
extern rtems_shell_cmd_t rtems_shell_CMDLS_Command;
.. _cmdchown:
cmdchown - Change user or owner of commands
-------------------------------------------
.. index:: cmdchown
**SYNOPSYS:**
.. code:: shell
cmdchown [OWNER][:[GROUP]] COMMAND...
**DESCRIPTION:**
This command changes the user or owner of a command.
**EXIT STATUS:**
This command returns 0 on success and non-zero if an error is encountered.
**NOTES:**
The current user must have an UID of zero or be the command owner to change the
owner or group.
**EXAMPLES:**
The following is an example of how to use ``cmdchown``:
.. code:: shell
[/] # cmdls help
r-xr-xr-x 0 0 help
[/] # cmdchown 1:1 help
[/] # cmdls help
r--r--r-- 1 1 help
**CONFIGURATION:**
.. index:: CONFIGURE_SHELL_NO_COMMAND_CMDCHOWN
.. index:: CONFIGURE_SHELL_COMMAND_CMDCHOWN
This command is included in the default shell command set. When building a
custom command set, define ``CONFIGURE_SHELL_COMMAND_CMDCHOWN`` to have this
command included.
This command can be excluded from the shell command set by defining
``CONFIGURE_SHELL_NO_COMMAND_CMDCHOWN`` when all shell commands have been
configured.
**PROGRAMMING INFORMATION:**
The configuration structure for the ``cmdchown`` has the following prototype:
.. code:: c
extern rtems_shell_cmd_t rtems_shell_CMDCHOWN_Command;
.. _cmdchmod:
cmdchmod - Change mode of commands
----------------------------------
.. index:: cmdchmod
**SYNOPSYS:**
.. code:: shell
cmdchmod OCTAL-MODE COMMAND...
**DESCRIPTION:**
This command changes the mode of a command.
**EXIT STATUS:**
This command returns 0 on success and non-zero if an error is encountered.
**NOTES:**
The current user must have an UID of zero or be the command owner to change the
mode.
**EXAMPLES:**
The following is an example of how to use ``cmdchmod``:
.. code:: shell
[/] # cmdls help
r-xr-xr-x 0 0 help
[/] # cmdchmod 544 help
[/] # cmdls help
r-xr--r-- 0 0 help
**CONFIGURATION:**
.. index:: CONFIGURE_SHELL_NO_COMMAND_CMDCHMOD
.. index:: CONFIGURE_SHELL_COMMAND_CMDCHMOD
This command is included in the default shell command set. When building a
custom command set, define ``CONFIGURE_SHELL_COMMAND_CMDCHMOD`` to have this
command included.
This command can be excluded from the shell command set by defining
``CONFIGURE_SHELL_NO_COMMAND_CMDCHMOD`` when all shell commands have been
configured.
**PROGRAMMING INFORMATION:**
The configuration structure for the ``cmdchmod`` has the following prototype:
.. code:: c
extern rtems_shell_cmd_t rtems_shell_CMDCHMOD_Command;
.. _date:
date - print or set current date and time
-----------------------------------------
.. index:: date
**SYNOPSYS:**
.. code:: shell
date
date DATE TIME
**DESCRIPTION:**
This command operates one of two modes. When invoked with no arguments, it
prints the current date and time. When invoked with both ``date`` and ``time``
arguments, it sets the current time.
The ``date`` is specified in ``YYYY-MM-DD`` format.
The ``time`` is specified in ``HH:MM:SS`` format.
**EXIT STATUS:**
This command returns 0 on success and non-zero if an error is encountered.
**NOTES:**
None.
**EXAMPLES:**
The following is an example of how to use ``date``:
.. code:: shell
SHLL [/] $ date
Fri Jan 1 00:00:09 1988
SHLL [/] $ date 2008-02-29 06:45:32
SHLL [/] $ date
Fri Feb 29 06:45:35 2008
**CONFIGURATION:**
.. index:: CONFIGURE_SHELL_NO_COMMAND_DATE
.. index:: CONFIGURE_SHELL_COMMAND_DATE
This command is included in the default shell command set. When building a
custom command set, define ``CONFIGURE_SHELL_COMMAND_DATE`` to have this command
included.
This command can be excluded from the shell command set by defining
``CONFIGURE_SHELL_NO_COMMAND_DATE`` when all shell commands have been
configured.
**PROGRAMMING INFORMATION:**
.. index:: rtems_shell_rtems_main_date
The ``date`` is implemented by a C language function which has the following
prototype:
.. code:: c
int rtems_shell_rtems_main_date(
int argc,
char **argv
);
The configuration structure for the ``date`` has the following prototype:
.. code:: c
extern rtems_shell_cmd_t rtems_shell_DATE_Command;
.. _echo:
echo - produce message in a shell script
----------------------------------------
.. index:: echo
**SYNOPSYS:**
.. code:: shell
echo [-n | -e] args ...
**DESCRIPTION:**
Echo prints its arguments on the standard output, separated by spaces. Unless
the *-n* option is present, a newline is output following the arguments. The
*-e* option causes echo to treat the escape sequences specially, as described
in the following paragraph. The *-e* option is the default, and is provided
solely for compatibility with other systems. Only one of the options *-n* and
*-e* may be given.
If any of the following sequences of characters is encountered during output,
the sequence is not output. Instead, the specified action is performed:
*\\b*
A backspace character is output.
*\\c*
Subsequent output is suppressed. This is normally used at the end of the
last argument to suppress the trailing newline that echo would otherwise
output.
*\\f*
Output a form feed.
*\\n*
Output a newline character.
*\\r*
Output a carriage return.
*\\t*
Output a (horizontal) tab character.
*\\v*
Output a vertical tab.
*\\0digits*
Output the character whose value is given by zero to three digits. If
there are zero digits, a nul character is output.
*\\\\*
Output a backslash.
**EXIT STATUS:**
This command returns 0 on success and non-zero if an error is encountered.
**NOTES:**
The octal character escape mechanism (\\0digits) differs from the C language
mechanism.
There is no way to force ``echo`` to treat its arguments literally, rather than
interpreting them as options and escape sequences.
**EXAMPLES:**
The following is an example of how to use ``echo``:
.. code:: shell
SHLL [/] $ echo a b c
a b c
SHLL [/] $ echo
**CONFIGURATION:**
.. index:: CONFIGURE_SHELL_NO_COMMAND_ECHO
.. index:: CONFIGURE_SHELL_COMMAND_ECHO
This command is included in the default shell command set. When building a
custom command set, define ``CONFIGURE_SHELL_COMMAND_ECHO`` to have this command
included.
This command can be excluded from the shell command set by defining
``CONFIGURE_SHELL_NO_COMMAND_ECHO`` when all shell commands have been
configured.
**PROGRAMMING INFORMATION:**
.. index:: rtems_shell_rtems_main_echo
The ``echo`` is implemented by a C language function which has the following
prototype:
.. code:: c
int rtems_shell_rtems_main_echo(
int argc,
char **argv
);
The configuration structure for the ``echo`` has the following prototype:
.. code:: c
extern rtems_shell_cmd_t rtems_shell_ECHO_Command;
**ORIGIN:**
The implementation and portions of the documentation for this command are from
NetBSD 4.0.
.. _sleep:
sleep - delay for a specified amount of time
--------------------------------------------
.. index:: sleep
**SYNOPSYS:**
.. code:: shell
sleep seconds
sleep seconds nanoseconds
**DESCRIPTION:**
This command causes the task executing the shell to block for the specified
number of ``seconds`` and ``nanoseconds``.
**EXIT STATUS:**
This command returns 0 on success and non-zero if an error is encountered.
**NOTES:**
This command is implemented using the ``nanosleep()`` method.
The command line interface is similar to the ``sleep`` command found on POSIX
systems but the addition of the ``nanoseconds`` parameter allows fine grained
delays in shell scripts without adding another command such as ``usleep``.
**EXAMPLES:**
The following is an example of how to use ``sleep``:
.. code:: shell
SHLL [/] $ sleep 10
SHLL [/] $ sleep 0 5000000
It is not clear from the above but there is a ten second pause after executing
the first command before the prompt is printed. The second command completes
very quickly from a human perspective and there is no noticeable delay in the
prompt being printed.
**CONFIGURATION:**
.. index:: CONFIGURE_SHELL_NO_COMMAND_SLEEP
.. index:: CONFIGURE_SHELL_COMMAND_SLEEP
This command is included in the default shell command set. When building a
custom command set, define ``CONFIGURE_SHELL_COMMAND_SLEEP`` to have this
command included.
This command can be excluded from the shell command set by defining
``CONFIGURE_SHELL_NO_COMMAND_SLEEP`` when all shell commands have been
configured.
**PROGRAMMING INFORMATION:**
.. index:: rtems_shell_rtems_main_sleep
The ``sleep`` is implemented by a C language function which has the following
prototype:
.. code:: c
int rtems_shell_rtems_main_sleep(
int argc,
char **argv
);
The configuration structure for the ``sleep`` has the following prototype:
.. code:: c
extern rtems_shell_cmd_t rtems_shell_SLEEP_Command;
.. _id:
id - show uid gid euid and egid
-------------------------------
.. index:: id
**SYNOPSYS:**
.. code:: shell
id
**DESCRIPTION:**
This command prints the user identity. This includes the user id (uid), group
id (gid), effective user id (euid), and effective group id (egid).
**EXIT STATUS:**
This command returns 0 on success and non-zero if an error is encountered.
**NOTES:**
Remember there is only one POSIX process in a single processor RTEMS
application. Each thread may have its own user identity and that identity is
used by the filesystem to enforce permissions.
**EXAMPLES:**
The first example of the ``id`` command is from a session logged
in as the normal user ``rtems``:
.. code:: shell
SHLL [/] # id
uid=1(rtems),gid=1(rtems),euid=1(rtems),egid=1(rtems)
The second example of the ``id`` command is from a session logged in as the
``root`` user:
.. code:: shell
SHLL [/] # id
uid=0(root),gid=0(root),euid=0(root),egid=0(root)
**CONFIGURATION:**
.. index:: CONFIGURE_SHELL_NO_COMMAND_ID
.. index:: CONFIGURE_SHELL_COMMAND_ID
This command is included in the default shell command set. When building a
custom command set, define ``CONFIGURE_SHELL_COMMAND_ID`` to have this command
included.
This command can be excluded from the shell command set by defining
``CONFIGURE_SHELL_NO_COMMAND_ID`` when all shell commands have been configured.
**PROGRAMMING INFORMATION:**
.. index:: rtems_shell_rtems_main_id
The ``id`` is implemented by a C language function which has the following
prototype:
.. code:: c
int rtems_shell_rtems_main_id(
int argc,
char **argv
);
The configuration structure for the ``id`` has the following prototype:
.. code:: c
extern rtems_shell_cmd_t rtems_shell_ID_Command;
.. _tty:
tty - show ttyname
------------------
.. index:: tty
**SYNOPSYS:**
.. code:: shell
tty
**DESCRIPTION:**
This command prints the file name of the device connected to standard input.
**EXIT STATUS:**
This command returns 0 on success and non-zero if an error is encountered.
**NOTES:**
NONE
**EXAMPLES:**
The following is an example of how to use ``tty``:
.. code:: shell
SHLL [/] $ tty
/dev/console
**CONFIGURATION:**
.. index:: CONFIGURE_SHELL_NO_COMMAND_TTY
.. index:: CONFIGURE_SHELL_COMMAND_TTY
This command is included in the default shell command set. When building a
custom command set, define ``CONFIGURE_SHELL_COMMAND_TTY`` to have this command
included.
This command can be excluded from the shell command set by defining
``CONFIGURE_SHELL_NO_COMMAND_TTY`` when all shell commands have been
configured.
**PROGRAMMING INFORMATION:**
.. index:: rtems_shell_rtems_main_tty
The ``tty`` is implemented by a C language function which has the following
prototype:
.. code:: c
int rtems_shell_rtems_main_tty(
int argc,
char **argv
);
The configuration structure for the ``tty`` has the following prototype:
.. code:: c
extern rtems_shell_cmd_t rtems_shell_TTY_Command;
.. _whoami:
whoami - print effective user id
--------------------------------
.. index:: whoami
**SYNOPSYS:**
.. code:: shell
whoami
**DESCRIPTION:**
This command displays the user name associated with the current effective user
id.
**EXIT STATUS:**
This command always succeeds.
**NOTES:**
None.
**EXAMPLES:**
The following is an example of how to use ``whoami``:
.. code:: shell
SHLL [/] $ whoami
rtems
**CONFIGURATION:**
.. index:: CONFIGURE_SHELL_NO_COMMAND_WHOAMI
.. index:: CONFIGURE_SHELL_COMMAND_WHOAMI
This command is included in the default shell command set. When building a
custom command set, define ``CONFIGURE_SHELL_COMMAND_WHOAMI`` to have this
command included.
This command can be excluded from the shell command set by defining
``CONFIGURE_SHELL_NO_COMMAND_WHOAMI`` when all shell commands have been
configured.
**PROGRAMMING INFORMATION:**
.. index:: rtems_shell_rtems_main_whoami
The ``whoami`` is implemented by a C language function which has the following
prototype:
.. code:: c
int rtems_shell_rtems_main_whoami(
int argc,
char **argv
);
The configuration structure for the ``whoami`` has the following prototype:
.. code:: c
extern rtems_shell_cmd_t rtems_shell_WHOAMI_Command;
.. _getenv:
getenv - print environment variable
-----------------------------------
.. index:: getenv
**SYNOPSYS:**
.. code:: shell
getenv variable
**DESCRIPTION:**
This command is used to display the value of a ``variable`` in the set of
environment variables.
**EXIT STATUS:**
This command will return 1 and print a diagnostic message if a failure occurs.
**NOTES:**
The entire RTEMS application shares a single set of environment variables.
**EXAMPLES:**
The following is an example of how to use ``getenv``:
.. code:: shell
SHLL [/] $ getenv BASEPATH
/mnt/hda1
**CONFIGURATION:**
.. index:: CONFIGURE_SHELL_NO_COMMAND_GETENV
.. index:: CONFIGURE_SHELL_COMMAND_GETENV
This command is included in the default shell command set. When building a
custom command set, define ``CONFIGURE_SHELL_COMMAND_GETENV`` to have this
command included.
This command can be excluded from the shell command set by defining
``CONFIGURE_SHELL_NO_COMMAND_GETENV`` when all shell commands have been
configured.
**PROGRAMMING INFORMATION:**
.. index:: rtems_shell_rtems_main_getenv
The ``getenv`` is implemented by a C language function which has the following
prototype:
.. code:: c
int rtems_shell_rtems_main_getenv(
int argc,
char **argv
);
The configuration structure for the ``getenv`` has the following prototype:
.. code:: c
extern rtems_shell_cmd_t rtems_shell_GETENV_Command;
.. _setenv:
setenv - set environment variable
---------------------------------
.. index:: setenv
**SYNOPSYS:**
.. code:: shell
setenv variable [value]
**DESCRIPTION:**
This command is used to add a new ``variable`` to the set of environment
variables or to modify the variable of an already existing ``variable``. If
the ``value`` is not provided, the ``variable`` will be set to the empty
string.
**EXIT STATUS:**
This command will return 1 and print a diagnostic message if a failure occurs.
**NOTES:**
The entire RTEMS application shares a single set of environment variables.
**EXAMPLES:**
The following is an example of how to use ``setenv``:
.. code:: shell
SHLL [/] $ setenv BASEPATH /mnt/hda1
**CONFIGURATION:**
.. index:: CONFIGURE_SHELL_NO_COMMAND_SETENV
.. index:: CONFIGURE_SHELL_COMMAND_SETENV
This command is included in the default shell command set. When building a
custom command set, define ``CONFIGURE_SHELL_COMMAND_SETENV`` to have this
command included.
This command can be excluded from the shell command set by defining
``CONFIGURE_SHELL_NO_COMMAND_SETENV`` when all shell commands have been
configured.
**PROGRAMMING INFORMATION:**
.. index:: rtems_shell_rtems_main_setenv
The ``setenv`` is implemented by a C language function which has the following
prototype:
.. code:: c
int rtems_shell_rtems_main_setenv(
int argc,
char **argv
);
The configuration structure for the ``setenv`` has the following prototype:
.. code:: c
extern rtems_shell_cmd_t rtems_shell_SETENV_Command;
.. _unsetenv:
unsetenv - unset environment variable
-------------------------------------
.. index:: unsetenv
**SYNOPSYS:**
.. code:: shell
unsetenv variable
**DESCRIPTION:**
This command is remove to a ``variable`` from the set of environment variables.
**EXIT STATUS:**
This command will return 1 and print a diagnostic message if a failure occurs.
**NOTES:**
The entire RTEMS application shares a single set of environment variables.
**EXAMPLES:**
The following is an example of how to use ``unsetenv``:
.. code:: shell
SHLL [/] $ unsetenv BASEPATH
**CONFIGURATION:**
.. index:: CONFIGURE_SHELL_NO_COMMAND_UNSETENV
.. index:: CONFIGURE_SHELL_COMMAND_UNSETENV
This command is included in the default shell command set. When building a
custom command set, define ``CONFIGURE_SHELL_COMMAND_UNSETENV`` to have this
command included.
This command can be excluded from the shell command set by defining
``CONFIGURE_SHELL_NO_COMMAND_UNSETENV`` when all shell commands have been
configured.
**PROGRAMMING INFORMATION:**
.. index:: rtems_shell_rtems_main_unsetenv
The ``unsetenv`` is implemented by a C language function which has the
following prototype:
.. code:: c
int rtems_shell_rtems_main_unsetenv(
int argc,
char **argv
);
The configuration structure for the ``unsetenv`` has the following prototype:
.. code:: c
extern rtems_shell_cmd_t rtems_shell_UNSETENV_Command;
.. _time:
time - time command execution
-----------------------------
.. index:: time
**SYNOPSYS:**
.. code:: c
time command [argument ...]
**DESCRIPTION:**
The time command executes and times a command. After the command finishes,
time writes the total time elapsed. Times are reported in seconds.
**EXIT STATUS:**
This command returns 0 on success and non-zero if an error is encountered.
**NOTES:**
None.
**EXAMPLES:**
The following is an example of how to use ``time``:
.. code:: shell
SHLL [/] $ time cp -r /nfs/directory /c
**CONFIGURATION:**
.. index:: CONFIGURE_SHELL_NO_COMMAND_TIME
.. index:: CONFIGURE_SHELL_COMMAND_TIME
This command is included in the default shell command set. When building a
custom command set, define ``CONFIGURE_SHELL_COMMAND_TIME`` to have this command
included.
This command can be excluded from the shell command set by defining
``CONFIGURE_SHELL_NO_COMMAND_TIME`` when all shell commands have been
configured.
**PROGRAMMING INFORMATION:**
.. index:: rtems_shell_rtems_main_time
The ``time`` is implemented by a C language function which has the following
prototype:
.. code:: c
int rtems_shell_rtems_main_time(
int argc,
char **argv
);
The configuration structure for the ``time`` has the following prototype:
.. code:: c
extern rtems_shell_cmd_t rtems_shell_TIME_Command;
.. _logoff:
logoff - logoff from the system
-------------------------------
.. index:: logoff
**SYNOPSYS:**
.. code:: shell
logoff
**DESCRIPTION:**
This command logs the user out of the shell.
**EXIT STATUS:**
This command does not return.
**NOTES:**
The system behavior when the shell is exited depends upon how the shell was
initiated. The typical behavior is that a login prompt will be displayed for
the next login attempt or that the connection will be dropped by the RTEMS
system.
**EXAMPLES:**
The following is an example of how to use ``logoff``:
.. code:: shell
SHLL [/] $ logoff
logoff from the system...
**CONFIGURATION:**
.. index:: CONFIGURE_SHELL_NO_COMMAND_LOGOFF
.. index:: CONFIGURE_SHELL_COMMAND_LOGOFF
This command is included in the default shell command set. When building a
custom command set, define ``CONFIGURE_SHELL_COMMAND_LOGOFF`` to have this
command included.
This command can be excluded from the shell command set by defining
``CONFIGURE_SHELL_NO_COMMAND_LOGOFF`` when all shell commands have been
configured.
**PROGRAMMING INFORMATION:**
.. index:: rtems_shell_rtems_main_logoff
The ``logoff`` is implemented by a C language function which has the following
prototype:
.. code:: c
int rtems_shell_rtems_main_logoff(
int argc,
char **argv
);
The configuration structure for the ``logoff`` has the following prototype:
.. code:: c
extern rtems_shell_cmd_t rtems_shell_LOGOFF_Command;
.. _rtc:
rtc - RTC driver configuration
------------------------------
.. index:: rtc
**SYNOPSYS:**
.. code:: shell
rtc
**CONFIGURATION:**
.. index:: CONFIGURE_SHELL_NO_COMMAND_RTC
.. index:: CONFIGURE_SHELL_COMMAND_RTC
This command is included in the default shell command set. When building a
custom command set, define ``CONFIGURE_SHELL_COMMAND_RTC`` to have this command
included.
This command can be excluded from the shell command set by defining
``CONFIGURE_SHELL_NO_COMMAND_RTC`` when all shell commands have been
configured.
.. _exit:
exit - exit the shell
---------------------
.. index:: exit
**SYNOPSYS:**
.. code:: shell
exit
**DESCRIPTION:**
This command causes the shell interpreter to ``exit``.
**EXIT STATUS:**
This command does not return.
**NOTES:**
In contrast to `logoff - logoff from the system`, this command is built into
the shell interpreter loop.
**EXAMPLES:**
The following is an example of how to use ``exit``:
.. code:: shell
SHLL [/] $ exit
Shell exiting
**CONFIGURATION:**
This command is always present and cannot be disabled.
**PROGRAMMING INFORMATION:**
The ``exit`` is implemented directly in the shell interpreter. There is no C
routine associated with it.