freebsd-dev/bin/kenv/kenv.1

.\"-
.\" Copyright (c) 2000  Peter Wemm <peter@FreeBSD.org>
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" $FreeBSD$
.\"
.Dd May 11, 2012
.Dt KENV 1
.Os
.Sh NAME
.Nm kenv
.Nd dump or modify the kernel environment
.Sh SYNOPSIS
.Nm
.Op Fl hNq
.Nm
.Op Fl qv
.Ar variable Ns Op = Ns Ar value
.Nm
.Op Fl q
.Fl u
.Ar variable
.Sh DESCRIPTION
The
.Nm
utility will dump the kernel environment if
invoked without arguments.
If the
.Fl h
option is specified, it will limit the report to kernel probe hints.
If an optional
.Ar variable
name is specified,
.Nm
will only report that value.
If the
.Fl N
option is specified,
.Nm
will only display variable names and not their values.
If the
.Fl u
option is specified,
.Nm
will delete the given environment variable.
If the environment variable is followed by an optional
.Ar value ,
.Nm
will set the environment variable to this value.
.Pp
If the
.Fl q
option is set, warnings normally printed as a result of being unable to
perform the requested operation will be suppressed.
.Pp
If the
.Fl v
option is set, the variable name will be printed out for the
environment variable in addition to the value when
.Nm
is executed with a variable name.
.Pp
Variables can be added to the kernel environment using the
.Pa /boot/loader.conf
file, or also statically compiled into the kernel using the statement
.Pp
.Dl Ic env Ar filename
.Pp
in the kernel config file.
The file can contain lines of the form
.Pp
.Dl name = "value"  # this is a comment
.Pp
where whitespace around
.Sq name
and
.Sq = ,
and everything after a
.Sq #
character, are ignored.
Almost any printable character except
.Sq =
is acceptable as part of a name.
Quotes are optional and necessary only if the value contains whitespace.
.Sh SEE ALSO
.Xr kenv 2 ,
.Xr config 5 ,
.Xr loader.conf 5 ,
.Xr loader 8
.Sh HISTORY
The
.Nm
utility appeared in
.Fx 4.1.1 .
/*- or .\"- or #- to begin license clauses. 2005-01-10 08:39:26 +00:00			`.\"-`
Spell "FreeBSD" with "F" and "BSD" in uppercase. 2001-08-13 16:33:00 +00:00			`.\" Copyright (c) 2000 Peter Wemm <peter@FreeBSD.org>`
Initial kenv(1) hack for dumping the kernel environment. This can be used to extract modified boot hints to make loader(8)-time changes "sticky". It tries to use \ style quoting so that it can be used directly with foo.conf files. It can also extract specific variables. 2000-07-08 08:33:40 +00:00			`.\"`
			`.\" Redistribution and use in source and binary forms, with or without`
			`.\" modification, are permitted provided that the following conditions`
			`.\" are met:`
			`.\" 1. Redistributions of source code must retain the above copyright`
			`.\" notice, this list of conditions and the following disclaimer.`
			`.\" 2. Redistributions in binary form must reproduce the above copyright`
			`.\" notice, this list of conditions and the following disclaimer in the`
			`.\" documentation and/or other materials provided with the distribution.`
			`.\"`
			.\" THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
			`.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE`
			`.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE`
			`.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE`
			`.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL`
			`.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS`
			`.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)`
			`.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT`
			`.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY`
			`.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF`
			`.\" SUCH DAMAGE.`
			`.\"`
			`.\" $FreeBSD$`
			`.\"`
I forgot to bump the manpage date. Reminded by: Garrett Cooper MFC after: 3 days X-MFC-with: r235297 2012-05-12 02:49:40 +00:00			`.Dd May 11, 2012`
Initial kenv(1) hack for dumping the kernel environment. This can be used to extract modified boot hints to make loader(8)-time changes "sticky". It tries to use \ style quoting so that it can be used directly with foo.conf files. It can also extract specific variables. 2000-07-08 08:33:40 +00:00			`.Dt KENV 1`
mdoc(7) police: removed HISTORY info from the .Os call. 2001-07-10 14:16:33 +00:00			`.Os`
Initial kenv(1) hack for dumping the kernel environment. This can be used to extract modified boot hints to make loader(8)-time changes "sticky". It tries to use \ style quoting so that it can be used directly with foo.conf files. It can also extract specific variables. 2000-07-08 08:33:40 +00:00			`.Sh NAME`
			`.Nm kenv`
Use the new functionalities provided by the kenv(2) syscall. Reviewed by: peter 2002-04-17 13:08:14 +00:00			`.Nd dump or modify the kernel environment`
Initial kenv(1) hack for dumping the kernel environment. This can be used to extract modified boot hints to make loader(8)-time changes "sticky". It tries to use \ style quoting so that it can be used directly with foo.conf files. It can also extract specific variables. 2000-07-08 08:33:40 +00:00			`.Sh SYNOPSIS`
mdoc(7) police: use the new features of the Nm macro. 2000-11-20 19:21:22 +00:00			`.Nm`
Add a -v and -N option to kenv(1), so it can be more easily used in scripts the way sysctl(8) is. The -N option, like in sysctl(8), displays only the kenv names, not their values. The -v option prints an individual kenv variable name with its value as name="value". This is the inverse of sysctl(8)'s -n flag, since the default behaviour of kenv(1) is already like sysctl(8) -n. Submitted by: Garrett Cooper < yanegomi AT gmail DOT com > MFC after: 1 week 2012-05-11 23:05:14 +00:00			`.Op Fl hNq`
Use the new functionalities provided by the kenv(2) syscall. Reviewed by: peter 2002-04-17 13:08:14 +00:00			`.Nm`
Add a -v and -N option to kenv(1), so it can be more easily used in scripts the way sysctl(8) is. The -N option, like in sysctl(8), displays only the kenv names, not their values. The -v option prints an individual kenv variable name with its value as name="value". This is the inverse of sysctl(8)'s -n flag, since the default behaviour of kenv(1) is already like sysctl(8) -n. Submitted by: Garrett Cooper < yanegomi AT gmail DOT com > MFC after: 1 week 2012-05-11 23:05:14 +00:00			`.Op Fl qv`
Use the new functionalities provided by the kenv(2) syscall. Reviewed by: peter 2002-04-17 13:08:14 +00:00			`.Ar variable Ns Op = Ns Ar value`
			`.Nm`
Add a "-q" quiet flag to kenv so that warnings can be suppressed. MFC after: 1 week 2005-09-13 19:01:53 +00:00			`.Op Fl q`
Use the new functionalities provided by the kenv(2) syscall. Reviewed by: peter 2002-04-17 13:08:14 +00:00			`.Fl u`
			`.Ar variable`
Initial kenv(1) hack for dumping the kernel environment. This can be used to extract modified boot hints to make loader(8)-time changes "sticky". It tries to use \ style quoting so that it can be used directly with foo.conf files. It can also extract specific variables. 2000-07-08 08:33:40 +00:00			`.Sh DESCRIPTION`
mdoc(7) police: markup nits. 2001-09-21 07:04:47 +00:00			`The`
mdoc(7) police: use the new features of the Nm macro. 2000-11-20 19:21:22 +00:00			`.Nm`
Use the new functionalities provided by the kenv(2) syscall. Reviewed by: peter 2002-04-17 13:08:14 +00:00			`utility will dump the kernel environment if`
			`invoked without arguments.`
Initial kenv(1) hack for dumping the kernel environment. This can be used to extract modified boot hints to make loader(8)-time changes "sticky". It tries to use \ style quoting so that it can be used directly with foo.conf files. It can also extract specific variables. 2000-07-08 08:33:40 +00:00			`If the`
			`.Fl h`
mdoc(7) police: markup nits. 2001-09-21 07:04:47 +00:00			`option is specified, it will limit the report to kernel probe hints.`
			`If an optional`
			`.Ar variable`
			`name is specified,`
Initial kenv(1) hack for dumping the kernel environment. This can be used to extract modified boot hints to make loader(8)-time changes "sticky". It tries to use \ style quoting so that it can be used directly with foo.conf files. It can also extract specific variables. 2000-07-08 08:33:40 +00:00			`.Nm`
			`will only report that value.`
Use the new functionalities provided by the kenv(2) syscall. Reviewed by: peter 2002-04-17 13:08:14 +00:00			`If the`
Add a -v and -N option to kenv(1), so it can be more easily used in scripts the way sysctl(8) is. The -N option, like in sysctl(8), displays only the kenv names, not their values. The -v option prints an individual kenv variable name with its value as name="value". This is the inverse of sysctl(8)'s -n flag, since the default behaviour of kenv(1) is already like sysctl(8) -n. Submitted by: Garrett Cooper < yanegomi AT gmail DOT com > MFC after: 1 week 2012-05-11 23:05:14 +00:00			`.Fl N`
			`option is specified,`
			`.Nm`
			`will only display variable names and not their values.`
			`If the`
Use the new functionalities provided by the kenv(2) syscall. Reviewed by: peter 2002-04-17 13:08:14 +00:00			`.Fl u`
			`option is specified,`
			`.Nm`
			`will delete the given environment variable.`
			`If the environment variable is followed by an optional`
mdoc(7) police: punctuation. 2002-05-29 18:52:02 +00:00			`.Ar value ,`
Use the new functionalities provided by the kenv(2) syscall. Reviewed by: peter 2002-04-17 13:08:14 +00:00			`.Nm`
			`will set the environment variable to this value.`
Add a "-q" quiet flag to kenv so that warnings can be suppressed. MFC after: 1 week 2005-09-13 19:01:53 +00:00			`.Pp`
			`If the`
			`.Fl q`
			`option is set, warnings normally printed as a result of being unable to`
			`perform the requested operation will be suppressed.`
Document how kernel environment can be statically compiled in, and reference a few related manpages. MFC after: 3 days 2009-01-13 12:19:43 +00:00			`.Pp`
Add a -v and -N option to kenv(1), so it can be more easily used in scripts the way sysctl(8) is. The -N option, like in sysctl(8), displays only the kenv names, not their values. The -v option prints an individual kenv variable name with its value as name="value". This is the inverse of sysctl(8)'s -n flag, since the default behaviour of kenv(1) is already like sysctl(8) -n. Submitted by: Garrett Cooper < yanegomi AT gmail DOT com > MFC after: 1 week 2012-05-11 23:05:14 +00:00			`If the`
			`.Fl v`
			`option is set, the variable name will be printed out for the`
			`environment variable in addition to the value when`
			`.Nm`
			`is executed with a variable name.`
			`.Pp`
Document how kernel environment can be statically compiled in, and reference a few related manpages. MFC after: 3 days 2009-01-13 12:19:43 +00:00			`Variables can be added to the kernel environment using the`
mdoc(7) markup. Approved by: avg (mentor), kib (mentor) MFC after: 3 days 2011-02-21 16:03:39 +00:00			`.Pa /boot/loader.conf`
Document how kernel environment can be statically compiled in, and reference a few related manpages. MFC after: 3 days 2009-01-13 12:19:43 +00:00			`file, or also statically compiled into the kernel using the statement`
			`.Pp`
			`.Dl Ic env Ar filename`
			`.Pp`
			`in the kernel config file.`
			`The file can contain lines of the form`
			`.Pp`
o Fix a typo. Bump .Dd for the previous delta. 2009-01-13 18:25:56 +00:00			`.Dl name = "value" # this is a comment`
Document how kernel environment can be statically compiled in, and reference a few related manpages. MFC after: 3 days 2009-01-13 12:19:43 +00:00			`.Pp`
Fix mandoc -Tlint warnings in bin/ Many style-level issues are still reported. Submitted by: Yuri Pankov <yuripv@gmx.com> Reviewed by: jilles (previous revision) Differential Revision: https://reviews.freebsd.org/D13334 2017-12-07 01:57:27 +00:00			`where whitespace around`
			`.Sq name`
			`and`
			`.Sq = ,`
			`and everything after a`
			`.Sq #`
			`character, are ignored.`
			`Almost any printable character except`
			`.Sq =`
			`is acceptable as part of a name.`
			`Quotes are optional and necessary only if the value contains whitespace.`
Initial kenv(1) hack for dumping the kernel environment. This can be used to extract modified boot hints to make loader(8)-time changes "sticky". It tries to use \ style quoting so that it can be used directly with foo.conf files. It can also extract specific variables. 2000-07-08 08:33:40 +00:00			`.Sh SEE ALSO`
Add a reference to the kenv(2) manpage. 2002-04-18 18:49:41 +00:00			`.Xr kenv 2 ,`
Document how kernel environment can be statically compiled in, and reference a few related manpages. MFC after: 3 days 2009-01-13 12:19:43 +00:00			`.Xr config 5 ,`
			`.Xr loader.conf 5 ,`
Initial kenv(1) hack for dumping the kernel environment. This can be used to extract modified boot hints to make loader(8)-time changes "sticky". It tries to use \ style quoting so that it can be used directly with foo.conf files. It can also extract specific variables. 2000-07-08 08:33:40 +00:00			`.Xr loader 8`
			`.Sh HISTORY`
mdoc(7) police: markup nits. 2001-09-21 07:04:47 +00:00			`The`
mdoc(7) police: use the new features of the Nm macro. 2000-11-20 19:21:22 +00:00			`.Nm`
mdoc(7) police: markup nits. 2001-09-21 07:04:47 +00:00			`utility appeared in`
kenv(1) first appeared in FreeBSD 4.1.1, not FreeBSD 5.0. PR: 23020 Submitted by: Simon Dick <simond@irrelevant.org> 2000-11-23 11:21:35 +00:00			`.Fx 4.1.1 .`