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KENV(1) 		     General Commands Manual			 KENV(1)

NAME
     kenv -- list or modify the kernel environment

SYNOPSIS
     kenv [-l | -s] [-hNq]
     kenv [-qv] variable[=value]
     kenv [-q] -u variable

DESCRIPTION
     The  kenv	utility will list all variables in the kernel environment if in-
     voked without arguments.

     If the -l option is specified, then  the  static  environment  provided  by
     loader(8)	will  be listed instead.  Similarly, the -s option will list the
     static environment defined by the kernel config.  Both of the -l and -s op-
     tions are dependent on the kernel being configured to preserve early kernel
     environments.  The default kernel configuration does not preserve these en-
     vironments.

     If the -h option is specified, it will limit the  report  to  kernel  probe
     hints.   If  an  optional variable name is specified, kenv will only report
     that value.  If the -N option is specified, kenv will only display variable
     names and not their values.  If the  -u  option  is  specified,  kenv  will
     delete the given environment variable.  If the environment variable is fol-
     lowed  by an optional value, kenv will set the environment variable to this
     value.

     If the -q option is set, warnings normally printed as a result of being un-
     able to perform the requested operation will be suppressed.

     If the -v option is set, the variable name will be printed out for the  en-
     vironment	variable  in  addition to the value when kenv is executed with a
     variable name.

     Variables	can   be   added   to	the   kernel   environment   using   the
     /boot/loader.conf	file,  or also statically compiled into the kernel using
     the statement

	   env filename

     in the kernel config file.  The file can contain lines of the form

	   name = value # this is a comment

     where whitespace around `name' and `=', and everything after a `#'  charac-
     ter,  are ignored.  Almost any printable character except `=' is acceptable
     as part of a name.  Quotes are optional and necessary  only  if  the  value
     contains whitespace.

EXAMPLES
     Show kernel probe hints variable names and filter for the uart device

	   $ kenv -h -N | grep uart
	   hint.uart.0.at
	   hint.uart.0.flags
	   hint.uart.0.irq
	   hint.uart.0.port
	   hint.uart.1.at
	   hint.uart.1.irq
	   hint.uart.1.port

     Show the value of a specific variable:

	   $ kenv hint.uart.1.at
	   isa

     Same as above but adding the name of the variable in the report:

	   $ kenv -v hint.uart.1.at
	   hint.uart.1.at="isa"

     Try to delete a variable and suppress warnings if any:

	   $ kenv -q -u hint.uart.1.at

     Set the value of the verbose_loading variable

	   $ kenv verbose_loading="YES"
	   verbose_loading="YES"

SEE ALSO
     kenv(2), config(5), loader.conf(5), loader(8)

HISTORY
     The kenv utility appeared in FreeBSD 4.1.1.

FreeBSD ports 15.1		  June 20, 2021 			 KENV(1)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=kenv&manpath=FreeBSD+15.1-RELEASE+and+Ports>

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