3 Stuff that needs to be done. This is organized by who plans to get around to
4 doing it eventually, but that doesn't mean they "own" the item. If you want to
5 do one of these bounce an email off the person it's listed under to see if they
6 have any suggestions how they plan to go about it, and to minimize conflicts
7 between your work and theirs. But otherwise, all of these are fair game.
9 Rob Landley suggested these:
10 Add a libbb/platform.c
11 Implement fdprintf() for platforms that haven't got one.
12 Implement bb_realpath() that can handle NULL on non-glibc.
15 Remove obsolete _() wrapper crud for internationalization we don't do.
16 Figure out where we need utf8 support, and add it.
19 The command shell situation is a big mess. We have three different
20 shells that don't really share any code, and the "standalone shell" doesn't
21 work all that well (especially not in a chroot environment), due to apps not
23 lash is phased out. hush can be configured down to be nearly as small,
26 General cleanup (should use ENABLE_FEATURE_INIT_SYSLOG).
28 Look at the full Single Unix Specification version 3 (available online at
29 "http://www.opengroup.org/onlinepubs/009695399/nfindex.html") and
30 figure out which of our apps are compliant, and what we're missing that
31 we might actually care about.
33 Even better would be some kind of automated compliance test harness that
34 exercises each command line option and the various corner cases.
36 How much internationalization should we do?
38 The low hanging fruit is UTF-8 character set support. We should do this.
39 (Vodz pointed out the shell's cmdedit as needing work here. What else?)
41 We also have lots of hardwired english text messages. Consolidating this
42 into some kind of message table not only makes translation easier, but
43 also allows us to consolidate redundant (or close) strings.
45 We probably don't want to be bloated with locale support. (Not unless we
46 can cleanly export it from our underlying C library without having to
47 concern ourselves with it directly. Perhaps a few specific things like a
48 config option for "date" are low hanging fruit here?)
50 What level should things happen at? How much do we care about
51 internationalizing the text console when X11 and xterms are so much better
52 at it? (There's some infrastructure here we don't implement: The
53 "unicode_start" and "unicode_stop" shell scripts need "vt-is-UTF8" and a
54 --unicode option to loadkeys. That implies a real loadkeys/dumpkeys
55 implementation to replace loadkmap/dumpkmap. Plus messing with console font
56 loading. Is it worth it, or do we just say "use X"?)
58 Individual compilation of applets.
59 It would be nice if busybox had the option to compile to individual applets,
60 for people who want an alternate implementation less bloated than the gnu
61 utils (or simply with less political baggage), but without it being one big
64 Turning libbb into a real dll is another possibility, especially if libbb
65 could export some of the other library interfaces we've already more or less
66 got the code for (like zlib).
67 buildroot - Make a "dogfood" option
68 Busybox 1.1 will be capable of replacing most gnu packages for real world
69 use, such as developing software or in a live CD. It needs wider testing.
71 Busybox should now be able to replace bzip2, coreutils, e2fsprogs, file,
72 findutils, gawk, grep, inetutils, less, modutils, net-tools, patch, procps,
73 sed, shadow, sysklogd, sysvinit, tar, util-linux, and vim. The resulting
74 system should be self-hosting (I.E. able to rebuild itself from source
75 code). This means it would need (at least) binutils, gcc, and make, or
78 It would be a good "eating our own dogfood" test if buildroot had the option
79 of using a "make allyesconfig" busybox instead of the all of the above
80 packages. Anything that's wrong with the resulting system, we can fix. (It
81 would be nice to be able to upgrade busybox to be able to replace bash and
82 diffutils as well, but we're not there yet.)
84 One example of an existing system that does this already is Firmware Linux:
85 http://www.landley.net/code/firmware
87 Busybox should have a sample initramfs build script. This depends on
88 bbsh, mdev, and switch_root.
90 Write a mkdep that doesn't segfault if there's a directory it doesn't
91 have permission to read, isn't based on manually editing the output of
92 lexx and yacc, doesn't make such a mess under include/config, etc.
93 Group globals into unions of structures.
94 Go through and turn all the global and static variables into structures,
95 and have all those structures be in a big union shared between processes,
96 so busybox uses less bss. (This is a big win on nommu machines.) See
97 sed.c and mdev.c for examples.
98 Go through bugs.busybox.net and close out all of that somehow.
99 This one's open to everybody, but I'll wind up doing it...
102 Bernhard Reutner-Fischer <busybox@busybox.net> suggests to look at these:
105 Cleanup any big users
106 Collate BUFSIZ IOBUF_SIZE MY_BUF_SIZE PIPE_PROGRESS_SIZE BUFSIZE PIPESIZE
107 make bb_common_bufsiz1 configurable, size wise.
108 make pipesize configurable, size wise.
109 Use bb_common_bufsiz1 throughout applets!
115 Make sure we handle empty files properly:
116 From the patch man page:
118 you can remove a file by sending out a context diff that compares
119 the file to be deleted with an empty file dated the Epoch. The
120 file will be removed unless patch is conforming to POSIX and the
121 -E or --remove-empty-files option is not given.
124 Should have simple fuzz factor support to apply patches at an offset which
125 shouldn't take up too much space.
127 And while we're at it, a new patch filename quoting format is apparently
128 coming soon: http://marc.theaimsgroup.com/?l=git&m=112927316408690&w=2
134 stty's visible() function and catv's guts are identical. Merge them into
135 an appropriate libbb function.
138 Several duplicate users of: grep -r "1024\*1024" * -B2 -A1
139 Merge to a single size_suffixes[] in libbb.
140 Users: head tail od_bloaty hexdump and (partially as it wouldn't hurt) svlogd
143 ./busybox tail -f foo.c~ TODO
144 should not print fmt=header_fmt for subsequent date >> TODO; i.e. only
145 fmt+ if another (not the current) file did change
147 Architectural issues:
149 bb_close() with fsync()
150 We should have a bb_close() in place of normal close, with a CONFIG_ option
151 to not just check the return value of close() for an error, but fsync().
152 Close can't reliably report anything useful because if write() accepted the
153 data then it either went out to the network or it's in cache or a pipe
154 buffer. Either way, there's no guarantee it'll make it to its final
155 destination before close() gets called, so there's no guarantee that any
156 error will be reported.
158 You need to call fsync() if you care about errors that occur after write(),
159 but that can have a big performance impact. So make it a config option.
162 Lots of archivers have the same general infrastructure. The directory
163 traversal code should be factored out, and the guts of each archiver could
164 be some setup code and a series of callbacks for "add this file",
165 "add this directory", "add this symlink" and so on.
167 This could clean up tar and zip, and make it cheaper to add cpio and ar
168 write support, and possibly even cheaply add things like mkisofs or
169 mksquashfs someday, if they become relevant.
172 Several existing applets (sort, vi, less...) read
173 a whole file into memory and act on it. Use open_read_close().
176 We have a CONFIG_BUFFER mechanism that lets us select whether to do memory
177 allocation on the stack or the heap. Unfortunately, we're not using it much.
178 We need to audit our memory allocations and turn a lot of malloc/free calls
179 into RESERVE_CONFIG_BUFFER/RELEASE_CONFIG_BUFFER.
180 For a start, see e.g. make EXTRA_CFLAGS=-Wlarger-than-64
182 And while we're at it, many of the CONFIG_FEATURE_CLEAN_UP #ifdefs will be
183 optimized out by the compiler in the stack allocation case (since there's no
184 free for an alloca()), and this means that various cleanup loops that just
185 call free might also be optimized out by the compiler if written right, so
186 we can yank those #ifdefs too, and generally clean up the code.
188 Switch CONFIG_SYMBOLS to ENABLE_SYMBOLS
190 In busybox 1.0 and earlier, configuration was done by CONFIG_SYMBOLS
191 that were either defined or undefined to indicate whether the symbol was
192 selected in the .config file. They were used with #ifdefs, ala:
200 In 1.1, we have new ENABLE_SYMBOLS which are always defined (as 0 or 1),
201 meaning you can still use them for preprocessor tests by replacing
202 "#ifdef CONFIG_SYMBOL" with "#if ENABLE_SYMBOL". But more importantly, we
203 can use them as a true or false test in normal C code:
205 if (ENABLE_SYMBOL && other_test) {
209 (Optimizing away if() statements that resolve to a constant value
210 is known as "dead code elimination", an optimization so old and simple that
211 Turbo Pascal for DOS did it twenty years ago. Even modern mini-compilers
212 like the Tiny C Compiler (tcc) and the Small Device C Compiler (SDCC)
213 perform dead code elimination.)
215 Right now, busybox.h is #including both "config.h" (defining the
216 CONFIG_SYMBOLS) and "bb_config.h" (defining the ENABLE_SYMBOLS). At some
217 point in the future, it would be nice to wean ourselves off of the
218 CONFIG versions. (Among other things, some defective build environments
219 leak the Linux kernel's CONFIG_SYMBOLS into the system's standard #include
220 files. We've experienced collisions before.)
223 This is more an unresolved issue than a to-do item. More thought is needed.
225 Normally we rely on exit() to free memory, close files and unmap segments
226 for us. This makes most calls to free(), close(), and unmap() optional in
227 busybox applets that don't intend to run for very long, and optional stuff
228 can be omitted to save size.
230 The idea was raised that we could simulate fork/exit with setjmp/longjmp
231 for _really_ brainless embedded systems, or speed up the standalone shell
232 by not forking. Doing so would require a reliable FEATURE_CLEAN_UP.
233 Unfortunately, this isn't as easy as it sounds.
235 The problem is, lots of things exit(), sometimes unexpectedly (xmalloc())
236 and sometimes reliably (bb_perror_msg_and_die() or show_usage()). This
237 jumps out of the normal flow control and bypasses any cleanup code we
238 put at the end of our applets.
240 It's possible to add hooks to libbb functions like xmalloc() and xopen()
241 to add their entries to a linked list, which could be traversed and
242 freed/closed automatically. (This would need to be able to free just the
243 entries after a checkpoint to be usable for a forkless standalone shell.
244 You don't want to free the shell's own resources.)
246 Right now, FEATURE_CLEAN_UP is more or less a debugging aid, to make things
247 like valgrind happy. It's also documentation of _what_ we're trusting
248 exit() to clean up for us. But new infrastructure to auto-free stuff would
249 render the existing FEATURE_CLEAN_UP code redundant.
251 For right now, exit() handles it just fine.
255 watchdog.c could autodetect the timer duration via:
256 if(!ioctl (fd, WDIOC_GETTIMEOUT, &tmo)) timer_duration = 1 + (tmo / 2);
257 Unfortunately, that needs linux/watchdog.h and that contains unfiltered
258 kernel types on some distros, which breaks the build.
260 use bb_error_msg where appropriate: See
261 egrep "(printf.*\([[:space:]]*(stderr|2)|[^_]write.*\([[:space:]]*(stderr|2))"
263 use bb_perror_msg where appropriate: See
266 possible code duplication ingroup() and is_a_group_member()
268 Move __get_hz() to a better place and (re)use it in route.c, ash.c, msh.c
271 Alot of duplication that wants cleanup.
273 in_ether duplicated in network/{interface,ifconfig}.c
275 unify progress_meter. wget, flash_eraseall, pipe_progress, fbsplash, setfiles.
280 Replace deprecated functions.
283 vdprintf() -> similar sized functionality
286 (TODO list after discussion 11.05.2009)
289 tc/brctl seem like fairly large things to try and tackle in your timeframe,
290 and i think people have posted attempts in the past. Adding additional
291 options to ip though seems reasonable.
293 * add tests for some applets
295 * implement POSIX utilities and audit them for POSIX conformance. then
296 audit them for GNU conformance. then document all your findings in a new
297 doc/conformance.txt file while perhaps implementing some of the missing
299 you can find the latest POSIX documentation (1003.1-2008) here:
300 http://www.opengroup.org/onlinepubs/9699919799/
301 and the complete list of all utilities that POSIX covers:
302 http://www.opengroup.org/onlinepubs/9699919799/idx/utilities.html
303 The first step would to generate a file/matrix what is already archived
306 * ntpdate/ntpd (see ntpclient and openntp for examples)
310 * rpcbind (former portmap) or equivalent
311 so that we don't have to use -o nolock on nfs mounts
313 * check IPV6 compliance
315 * generate a mini example using kernel+busybox only (+libc) for example
317 * more support for advanced linux 2.6.x features, see: iotop
318 most likely there is more
320 * even more support for statistics: mpstat, iostat, powertop....