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c8f3dea90e
Commit 858805b336be ("kbuild: add $(BASH) to run scripts with
bash-extension") shed light on portability issues. Here is another one.
Since commit f07726048d59 ("Fix handling of backlash character in
LINUX_COMPILE_BY name"), we must escape a backslash contained in
LINUX_COMPILE_BY. This is not working on such distros as Ubuntu.
As the POSIX spec [1] says, if any of the operands contain a backslash
( '\' ) character, the results are implementation-defined.
The actual shell of /bin/sh could be bash, dash, etc. depending on
distros, and the behavior of builtin echo command is different among
them.
The bash builtin echo, unless -e is given, copies the arguments to
stdout without expanding escape sequences (BSD-like behavior).
The dash builtin echo, in contrast, adopts System V behavior, which
does expand escape sequences without any option given.
Even non-builtin /bin/echo behaves differently depending on the system.
Due to these variations, echo is considered as a non-portable command.
Using printf is the common solution to avoid the portability issue.
[1] https://pubs.opengroup.org/onlinepubs/009695399/utilities/echo.html
Fixes: 858805b336be ("kbuild: add $(BASH) to run scripts with bash-extension")
Reported-by: XXing Wei <xxing.wei@unisoc.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.