Credits:
Matt Kraai - initial writeup
Mark Whitley - the remix
-Thomas Lundquist - Added stuff for the new directory layout.
+Thomas Lundquist - Trying to keep it updated.
+
+When doing this you should consider using the latest git HEAD.
+This is a good thing if you plan to getting it committed into mainline.
Initial Write
-------------
boilerplate. Be sure to name the main function <applet>_main instead of main.
And be sure to put it in <applet>.c. Usage does not have to be taken care of by
your applet.
-Make sure to #include "busybox.h" as the first include file in your applet so
-the bb_config.h and appropriate platform specific files are included properly.
+Make sure to #include "libbb.h" as the first include file in your applet.
For a new applet mu, here is the code that would go in mu.c:
+(busybox.h already includes most usual header files. You do not need
+#include <stdio.h> etc...)
+
+
----begin example code------
/* vi: set sw=4 ts=4: */
*
* Copyright (C) [YEAR] by [YOUR NAME] <YOUR EMAIL>
*
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2, see file LICENSE in this source tree.
*/
-#include "busybox.h"
-#include <other.h>
+#include "libbb.h"
+#include "other.h"
+int mu_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int mu_main(int argc, char **argv)
{
int fd;
+ ssize_t n;
char mu;
- fd = bb_xopen("/dev/random", O_RDONLY);
+ fd = xopen("/dev/random", O_RDONLY);
if ((n = safe_read(fd, &mu, 1)) < 1)
bb_perror_msg_and_die("/dev/random");
Additionally, if you have any useful, general-purpose functions in your
applet that could be useful in other applets, consider putting them in libbb.
+And it may be possible that some of the other applets uses functions you
+could use. If so, you have to rip the function out of the applet and make
+a libbb function out of it.
+
+Adding a libbb function:
+------------------------
+
+Make a new file named <function_name>.c
+
+----start example code------
+
+#include "libbb.h"
+#include "other.h"
+
+int function(char *a)
+{
+ return *a;
+}
+
+----end example code------
+
+Add <function_name>.o in the right alphabetically sorted place
+in libbb/Kbuild.src. You should look at the conditional part of
+libbb/Kbuild.src as well.
+
+You should also try to find a suitable place in include/libbb.h for
+the function declaration. If not, add it somewhere anyway, with or without
+ifdefs to include or not.
+
+You can look at libbb/Config.src and try to find out if the function is
+tunable and add it there if it is.
+
Placement / Directory
---------------------
Make sure you find the appropriate places in the files, the applets are
sorted alphabetically.
-Add the applet to Makefile.in in the chosen directory:
+Add the applet to Kbuild.src in the chosen directory:
-obj-$(CONFIG_MU) += mu.o
+lib-$(CONFIG_MU) += mu.o
-Add the applet to Config.in in the chosen directory:
+Add the applet to Config.src in the chosen directory:
-config CONFIG_MU
+config MU
bool "MU"
default n
help
Usage String(s)
---------------
-Next, add usage information for you applet to include/usage.h.
+Next, add usage information for you applet to include/usage.src.h.
This should look like the following:
#define mu_trivial_usage \
If your program supports flags, the flags should be mentioned on the first
line (-[abcde]) and a detailed description of each flag should go in the
mu_full_usage section, one flag per line. (Numerous examples of this
-currently exist in usage.h.)
+currently exist in usage.src.h.)
Header Files
------------
-Next, add an entry to include/applets.h. Be *sure* to keep the list
+Next, add an entry to include/applets.src.h. Be *sure* to keep the list
in alphabetical order, or else it will break the binary-search lookup
algorithm in busybox.c and the Gods of BusyBox smite you. Yea, verily:
+Be sure to read the top of applets.src.h before adding your applet.
+
/* all programs above here are alphabetically "less than" 'mu' */
- #ifdef CONFIG_MU
- APPLET("mu", mu_main, _BB_DIR_USR_BIN, mu_usage)
- #endif
+ IF_MU(APPLET(mu, BB_DIR_USR_BIN, BB_SUID_DROP))
/* all programs below here are alphabetically "greater than" 'mu' */
-Documentation
--------------
-
-If you're feeling especially nice, you should also document your applet in the
-docs directory (but nobody ever does that).
-
-Adding some text to docs/Configure.help is a nice start.
-
-
The Grand Announcement
----------------------
-Then create a diff -urN of the files you added and/or modified. Typically:
- <appletdir>/<applet>.c
- include/usage.c
- include/applets.h
- <appletdir>/Makefile.in
- <appletdir>/config.in
+Then create a diff by adding the new files to git (remember your libbb files)
+ git add <where you put it>/mu.c
+eventually also:
+ git add libbb/function.c
+then
+ git commit
+ git format-patch HEAD^
and send it to the mailing list:
busybox@busybox.net
http://busybox.net/mailman/listinfo/busybox
projects / platform / upstream / busybox.git / blobdiff