From 11da3403e91c9f510495c75d07750b6ac3c3b2e7 Mon Sep 17 00:00:00 2001 From: Tom Rini Date: Fri, 24 Oct 2025 10:02:57 -0600 Subject: doc: usage: Add general rule for `$?` For nearly all commands in U-Boot the '?' variable is handled the same way with 0 meaning success, 1 meaning any failure. Explain this in the general rules section of the cmdline documentation (with a link to a counter example) and then remove the redundant wording from most commands. We retain a section about the return value in a number of places where we are doing something such as always returning a specific value or we have useful additional information to go along with the normal return codes. Signed-off-by: Tom Rini Reviewed-by: Heinrich Schuchardt --- doc/usage/cmdline.rst | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'doc/usage/cmdline.rst') diff --git a/doc/usage/cmdline.rst b/doc/usage/cmdline.rst index 58240c5279c..79b9baf7bfe 100644 --- a/doc/usage/cmdline.rst +++ b/doc/usage/cmdline.rst @@ -55,6 +55,12 @@ General rules command will cause "run" to terminate, i. e. the remaining variables are not executed. +#. The variable ``$?`` will be set as the return value of any command. The + possible values are 0 on success or 1 on any error e. g. invalid syntax or + failure of the command. Any exceptions to this are documented by the + specific command, e.g. the :doc:`for command ` sets ``$?`` based on + the last command run within the loop. + Representing numbers -------------------- -- cgit v1.2.3