[PATCH 1/1] doc: man-page for the printenv command

Heinrich Schuchardt
2022-06-19T12:01:35Z

Privide a man-page for the printenv command.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
---
doc/usage/cmd/printenv.rst | 90 ++++++++++++++++++++++++++++++++++++++
doc/usage/index.rst | 1 +
2 files changed, 91 insertions(+)
create mode 100644 doc/usage/cmd/printenv.rst

diff --git a/doc/usage/cmd/printenv.rst b/doc/usage/cmd/printenv.rst
new file mode 100644
index 0000000000..6f1c46006b
--- /dev/null
+++ b/doc/usage/cmd/printenv.rst
@@ -0,0 +1,90 @@
+.. SPDX-License-Identifier: GPL-2.0+:
+
+printenv command
+================
+
+Synopsis
+--------
+
+::
+
+ printenv [-a] [name ...]
+ printenv -e [-guid guid][-n] [name]
+
+Description
+-----------
+
+The printenv command is used to print environment or UEFI variables.
+
+\-a
+ Print environment variables starting with a period ('.').
+
+\-e
+ Print UEFI variables. Without -e environment variables are printed.
+
+\-guid *guid*
+ Specify vendor GUID *guid*. If none is specified, all UEFI variables with
+ the specified name are printed irrespective of their vendor GUID.
+
+\-n
+ don't show hexadecimal dump of value
+
+name
+ Variable name. If no name is provided all variables are printed.
+ Multiple environment variable names may be specified.
+
+Examples
+--------
+
+The following examples demonstrates the effect of the *-a* flag when displaying
+environment variables:
+
+::
+
+ => setenv .foo bar
+ => printenv
+ arch=sandbox
+ baudrate=115200
+ board=sandbox
+ ...
+ stdout=serial,vidconsole
+
+ Environment size: 644/8188 bytes
+ => printenv -a
+ .foo=bar
+ arch=sandbox
+ baudrate=115200
+ board=sandbox
+ ...
+ stdout=serial,vidconsole
+
+ Environment size: 653/8188 bytes
+ =>
+
+The next example shows the effect of the *-n* flag when displaying an UEFI
+variable and how to specify a vendor GUID:
+
+::
+
+ => printenv -e -guid 8be4df61-93ca-11d2-aa0d-00e098032b8c PlatformLangCodes
+ PlatformLangCodes:
+ 8be4df61-93ca-11d2-aa0d-00e098032b8c (EFI_GLOBAL_VARIABLE_GUID)
+ BS|RT|RO, DataSize = 0x6
+ 00000000: 65 6e 2d 55 53 00 en-US.
+ => printenv -e -n PlatformLangCodes
+ PlatformLangCodes:
+ 8be4df61-93ca-11d2-aa0d-00e098032b8c (EFI_GLOBAL_VARIABLE_GUID)
+ BS|RT|RO, DataSize = 0x6
+ =>
+
+Configuration
+=============
+
+UEFI variables are only supported if CONFIG_CMD_NVEDIT_EFI=y. The value of UEFI
+variables can only be displayed if CONFIG_HEXDUMP=y.
+
+Return value
+------------
+
+The return value $? is 1 (false) if a specified variable is not found.
+Otherwise $? is set to 0 (true).
diff --git a/doc/usage/index.rst b/doc/usage/index.rst
index c03f4aef9e..cbe49244c8 100644
--- a/doc/usage/index.rst
+++ b/doc/usage/index.rst
@@ -48,6 +48,7 @@ Shell commands
cmd/md
cmd/mmc
cmd/pinmux
+ cmd/printenv
cmd/pstore
cmd/qfw
cmd/reset
--
2.36.1