2 .\" Copyright (c) 2000 Peter Wemm <peter@FreeBSD.org>
4 .\" Redistribution and use in source and binary forms, with or without
5 .\" modification, are permitted provided that the following conditions
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9 .\" 2. Redistributions in binary form must reproduce the above copyright
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13 .\" THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
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15 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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32 .Nd dump or modify the kernel environment
38 .Ar variable Ns Op = Ns Ar value
46 utility will dump the kernel environment if
47 invoked without arguments.
50 option is specified, it will limit the report to kernel probe hints.
55 will only report that value.
60 will only display variable names and not their values.
65 will delete the given environment variable.
66 If the environment variable is followed by an optional
69 will set the environment variable to this value.
73 option is set, warnings normally printed as a result of being unable to
74 perform the requested operation will be suppressed.
78 option is set, the variable name will be printed out for the
79 environment variable in addition to the value when
81 is executed with a variable name.
83 Variables can be added to the kernel environment using the
85 file, or also statically compiled into the kernel using the statement
87 .Dl Ic env Ar filename
89 in the kernel config file.
90 The file can contain lines of the form
92 .Dl name = "value" # this is a comment
94 where whitespace around
98 and everything after a
100 character, are ignored.
101 Almost any printable character except
103 is acceptable as part of a name.
104 Quotes are optional and necessary only if the value contains whitespace.
106 Show kernel probe hints variable names and filter for the uart
108 .Bd -literal -offset indent
109 $ kenv -h -N | grep uart
119 Show the value of a specific variable:
120 .Bd -literal -offset indent
121 $ kenv hint.uart.1.at
125 Same as above but adding the name of the variable in the report:
126 .Bd -literal -offset indent
127 $ kenv -v hint.uart.1.at
131 Try to delete a variable and suppress warnings if any:
132 .Bd -literal -offset indent
133 $ kenv -q -u hint.uart.1.at
139 .Bd -literal -offset indent
140 $ kenv verbose_loading="YES"
141 verbose_loading="YES"