zephyr/lib/posix/getopt/README
Jakub Rzeszutko d4559f53fa lib: getopt: rework and extend getopt library
Getopt has been rework in this way that calling it does not require
extra state parameter and its execution is thread safe.
Global parameters describing the state of the getopt function have been
made available to ensure full API compatibility in using this library.
However, referencing these global variables directly is not thread
safe. In order to get the state of the getopt function for the thread
that is currently using it, call: getopt_state_get();

Extended the library with getopt_long and getopt_long_only functions.

Moved getopt libary from utils to posix.

Signed-off-by: Jakub Rzeszutko <jakub.rzeszutko@nordicsemi.no>
2022-01-06 21:26:59 +01:00

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[GetOpt]
#####################
Origin:
[Lattera FreeBSD]
[https://github.com/lattera/freebsd/blob/master/lib/libc/stdlib/getopt.c]
Status:
[So far Zephyr samples were using getopt implementation from: argtable3.c.]
Purpose:
[Shell users would like to parse options passed to the command handler.]
Description:
[This library is going to be used by the shell module. Some shell users
are not satisfied with subcommands alone and need to use the options for
commands as well. A library is needed that allows the developer to parse
the arguments string, looking for supported options. Typically, this task
is accomplished by the getopt function.
For this purpose I decided to port the getopt library available
in the FreeBSD project. I had to modify it so that it could be used
by all instances of the shell at the same time.
Originally this function was using global variables which were defining
its state. In my implementation I put those variables in a structure
and a pointer to that structure is passed as an additional parameter
to getopt function. In proposed implementation each shell backend has its
own getopt function state structure which it uses.
This module is intended to be used inside the shell command handler
by the abstraction layer "SHELL_GETOPT". For example:
while ((char c = shell_getopt(shell, argc, argv, "abhc:")) != -1) {
/* some code */
}
]
Dependencies:
[This package does not depend on any other component.
Zephyr project will only need this component if the user configures a shell
module: SHELL_GETOPT.]
URL:
[https://github.com/lattera/freebsd]
commit:
[324e4c082c14aebf00f8dbee0fb7ad285393756a]
Maintained-by:
[External]
License:
[BSD 3-Clause "New" or "Revised" License]
License Link:
[BSD 3-Clause used in getopt: https://spdx.org/licenses/BSD-3-Clause.html]
[Project license: https://github.com/lattera/freebsd/blob/master/COPYRIGHT]