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"Das U-Boot" Source Tree
1.. SPDX-License-Identifier: GPL-2.0+:
2
3.. index::
4 single: printenv (command)
5
6printenv command
7================
8
9Synopsis
10--------
11
12::
13
14 printenv [-a] [name ...]
15 printenv -e [-guid guid][-n] [name]
16
17Description
18-----------
19
20The printenv command is used to print environment or UEFI variables.
21
22\-a
23 Print environment variables starting with a period ('.').
24
25\-e
26 Print UEFI variables. Without -e environment variables are printed.
27
28\-guid *guid*
29 Specify vendor GUID *guid*. If none is specified, all UEFI variables with
30 the specified name are printed irrespective of their vendor GUID.
31
32\-n
33 don't show hexadecimal dump of value
34
35name
36 Variable name. If no name is provided, all variables are printed.
37 Multiple environment variable names may be specified.
38
39Examples
40--------
41
42The following examples demonstrates the effect of the *-a* flag when displaying
43environment variables:
44
45::
46
47 => setenv .foo bar
48 => printenv
49 arch=sandbox
50 baudrate=115200
51 board=sandbox
52 ...
53 stdout=serial,vidconsole
54
55 Environment size: 644/8188 bytes
56 => printenv -a
57 .foo=bar
58 arch=sandbox
59 baudrate=115200
60 board=sandbox
61 ...
62 stdout=serial,vidconsole
63
64 Environment size: 653/8188 bytes
65 =>
66
67The next example shows the effect of the *-n* flag when displaying an UEFI
68variable and how to specify a vendor GUID:
69
70::
71
72 => printenv -e -guid 8be4df61-93ca-11d2-aa0d-00e098032b8c PlatformLangCodes
73 PlatformLangCodes:
74 8be4df61-93ca-11d2-aa0d-00e098032b8c (EFI_GLOBAL_VARIABLE_GUID)
75 BS|RT|RO, DataSize = 0x6
76 00000000: 65 6e 2d 55 53 00 en-US.
77 => printenv -e -n PlatformLangCodes
78 PlatformLangCodes:
79 8be4df61-93ca-11d2-aa0d-00e098032b8c (EFI_GLOBAL_VARIABLE_GUID)
80 BS|RT|RO, DataSize = 0x6
81 =>
82
83Configuration
84-------------
85
86UEFI variables are only supported if CONFIG_CMD_NVEDIT_EFI=y. The value of UEFI
87variables can only be displayed if CONFIG_HEXDUMP=y.
88
89Return value
90------------
91
92The return value $? is 1 (false) if a specified variable is not found.
93Otherwise $? is set to 0 (true).