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 this:
10 Implement bb_realpath() that can handle NULL on non-glibc.
12 Remove obsolete _() wrapper crud for internationalization we don't do.
13 Figure out where we need utf8 support, and add it.
16 The command shell situation is a mess. We have two different
17 shells that don't really share any code, and the "standalone shell" doesn't
18 work all that well (especially not in a chroot environment), due to apps not
22 Look at the full Single Unix Specification version 3 (available online at
23 "http://www.opengroup.org/onlinepubs/009695399/nfindex.html") and
24 figure out which of our apps are compliant, and what we're missing that
25 we might actually care about.
27 Even better would be some kind of automated compliance test harness that
28 exercises each command line option and the various corner cases.
31 How much internationalization should we do?
33 The low hanging fruit is UTF-8 character set support. We should do this.
34 (Vodz pointed out the shell's cmdedit as needing work here. What else?)
36 We also have lots of hardwired english text messages. Consolidating this
37 into some kind of message table not only makes translation easier, but
38 also allows us to consolidate redundant (or close) strings.
40 We probably don't want to be bloated with locale support. (Not unless we
41 can cleanly export it from our underlying C library without having to
42 concern ourselves with it directly. Perhaps a few specific things like a
43 config option for "date" are low hanging fruit here?)
45 What level should things happen at? How much do we care about
46 internationalizing the text console when X11 and xterms are so much better
47 at it? (There's some infrastructure here we don't implement: The
48 "unicode_start" and "unicode_stop" shell scripts need "vt-is-UTF8" and a
49 --unicode option to loadkeys. That implies a real loadkeys/dumpkeys
50 implementation to replace loadkmap/dumpkmap. Plus messing with console font
51 loading. Is it worth it, or do we just say "use X"?)
53 Individual compilation of applets.
54 It would be nice if busybox had the option to compile to individual applets,
55 for people who want an alternate implementation less bloated than the gnu
56 utils (or simply with less political baggage), but without it being one big
59 Turning libbb into a real dll is another possibility, especially if libbb
60 could export some of the other library interfaces we've already more or less
61 got the code for (like zlib).
62 buildroot - Make a "dogfood" option
63 Busybox 1.1 will be capable of replacing most gnu packages for real world
64 use, such as developing software or in a live CD. It needs wider testing.
66 Busybox should now be able to replace bzip2, coreutils, e2fsprogs, file,
67 findutils, gawk, grep, inetutils, less, modutils, net-tools, patch, procps,
68 sed, shadow, sysklogd, sysvinit, tar, util-linux, and vim. The resulting
69 system should be self-hosting (I.E. able to rebuild itself from source
70 code). This means it would need (at least) binutils, gcc, and make, or
73 It would be a good "eating our own dogfood" test if buildroot had the option
74 of using a "make allyesconfig" busybox instead of the all of the above
75 packages. Anything that's wrong with the resulting system, we can fix. (It
76 would be nice to be able to upgrade busybox to be able to replace bash and
77 diffutils as well, but we're not there yet.)
79 One example of an existing system that does this already is Firmware Linux:
80 http://www.landley.net/code/firmware
82 Busybox should have a sample initramfs build script. This depends on
83 bbsh, mdev, and switch_root.
85 Write a mkdep that doesn't segfault if there's a directory it doesn't
86 have permission to read, isn't based on manually editing the output of
87 lexx and yacc, doesn't make such a mess under include/config, etc.
88 Group globals into unions of structures.
89 Go through and turn all the global and static variables into structures,
90 and have all those structures be in a big union shared between processes,
91 so busybox uses less bss. (This is a big win on nommu machines.) See
92 sed.c and mdev.c for examples.
93 Go through bugs.busybox.net and close out all of that somehow.
94 This one's open to everybody, but I'll wind up doing it...
97 Bernhard Reutner-Fischer <busybox@busybox.net> suggests to look at these:
100 Cleanup any big users
101 Collate BUFSIZ IOBUF_SIZE MY_BUF_SIZE PIPE_PROGRESS_SIZE BUFSIZE PIPESIZE
102 make bb_common_bufsiz1 configurable, size wise.
103 make pipesize configurable, size wise.
104 Use bb_common_bufsiz1 throughout applets!
110 Make sure we handle empty files properly:
111 From the patch man page:
113 you can remove a file by sending out a context diff that compares
114 the file to be deleted with an empty file dated the Epoch. The
115 file will be removed unless patch is conforming to POSIX and the
116 -E or --remove-empty-files option is not given.
119 Should have simple fuzz factor support to apply patches at an offset which
120 shouldn't take up too much space.
122 And while we're at it, a new patch filename quoting format is apparently
123 coming soon: http://marc.theaimsgroup.com/?l=git&m=112927316408690&w=2
126 stty's visible() function and catv's guts are identical. Merge them into
127 an appropriate libbb function.
130 Several duplicate users of: grep -r "1024\*1024" * -B2 -A1
131 Merge to a single size_suffixes[] in libbb.
132 Users: head tail od_bloaty hexdump and (partially as it wouldn't hurt) svlogd
135 ./busybox tail -f foo.c~ TODO
136 should not print fmt=header_fmt for subsequent date >> TODO; i.e. only
137 fmt+ if another (not the current) file did change
139 Architectural issues:
141 bb_close() with fsync()
142 We should have a bb_close() in place of normal close, with a CONFIG_ option
143 to not just check the return value of close() for an error, but fsync().
144 Close can't reliably report anything useful because if write() accepted the
145 data then it either went out to the network or it's in cache or a pipe
146 buffer. Either way, there's no guarantee it'll make it to its final
147 destination before close() gets called, so there's no guarantee that any
148 error will be reported.
150 You need to call fsync() if you care about errors that occur after write(),
151 but that can have a big performance impact. So make it a config option.
154 Lots of archivers have the same general infrastructure. The directory
155 traversal code should be factored out, and the guts of each archiver could
156 be some setup code and a series of callbacks for "add this file",
157 "add this directory", "add this symlink" and so on.
159 This could clean up tar and zip, and make it cheaper to add cpio and ar
160 write support, and possibly even cheaply add things like mkisofs or
161 mksquashfs someday, if they become relevant.
164 Several existing applets (sort, vi, less...) read
165 a whole file into memory and act on it. Use open_read_close().
168 We have a CONFIG_BUFFER mechanism that lets us select whether to do memory
169 allocation on the stack or the heap. Unfortunately, we're not using it much.
170 We need to audit our memory allocations and turn a lot of malloc/free calls
171 into RESERVE_CONFIG_BUFFER/RELEASE_CONFIG_BUFFER.
172 For a start, see e.g. make EXTRA_CFLAGS=-Wlarger-than-64
174 And while we're at it, many of the CONFIG_FEATURE_CLEAN_UP #ifdefs will be
175 optimized out by the compiler in the stack allocation case (since there's no
176 free for an alloca()), and this means that various cleanup loops that just
177 call free might also be optimized out by the compiler if written right, so
178 we can yank those #ifdefs too, and generally clean up the code.
180 Switch CONFIG_SYMBOLS to ENABLE_SYMBOLS
182 In busybox 1.0 and earlier, configuration was done by CONFIG_SYMBOLS
183 that were either defined or undefined to indicate whether the symbol was
184 selected in the .config file. They were used with #ifdefs, ala:
192 In 1.1, we have new ENABLE_SYMBOLS which are always defined (as 0 or 1),
193 meaning you can still use them for preprocessor tests by replacing
194 "#ifdef CONFIG_SYMBOL" with "#if ENABLE_SYMBOL". But more importantly, we
195 can use them as a true or false test in normal C code:
197 if (ENABLE_SYMBOL && other_test) {
201 (Optimizing away if() statements that resolve to a constant value
202 is known as "dead code elimination", an optimization so old and simple that
203 Turbo Pascal for DOS did it twenty years ago. Even modern mini-compilers
204 like the Tiny C Compiler (tcc) and the Small Device C Compiler (SDCC)
205 perform dead code elimination.)
207 Right now, busybox.h is #including both "config.h" (defining the
208 CONFIG_SYMBOLS) and "bb_config.h" (defining the ENABLE_SYMBOLS). At some
209 point in the future, it would be nice to wean ourselves off of the
210 CONFIG versions. (Among other things, some defective build environments
211 leak the Linux kernel's CONFIG_SYMBOLS into the system's standard #include
212 files. We've experienced collisions before.)
215 This is more an unresolved issue than a to-do item. More thought is needed.
217 Normally we rely on exit() to free memory, close files and unmap segments
218 for us. This makes most calls to free(), close(), and unmap() optional in
219 busybox applets that don't intend to run for very long, and optional stuff
220 can be omitted to save size.
222 The idea was raised that we could simulate fork/exit with setjmp/longjmp
223 for _really_ brainless embedded systems, or speed up the standalone shell
224 by not forking. Doing so would require a reliable FEATURE_CLEAN_UP.
225 Unfortunately, this isn't as easy as it sounds.
227 The problem is, lots of things exit(), sometimes unexpectedly (xmalloc())
228 and sometimes reliably (bb_perror_msg_and_die() or show_usage()). This
229 jumps out of the normal flow control and bypasses any cleanup code we
230 put at the end of our applets.
232 It's possible to add hooks to libbb functions like xmalloc() and xopen()
233 to add their entries to a linked list, which could be traversed and
234 freed/closed automatically. (This would need to be able to free just the
235 entries after a checkpoint to be usable for a forkless standalone shell.
236 You don't want to free the shell's own resources.)
238 Right now, FEATURE_CLEAN_UP is more or less a debugging aid, to make things
239 like valgrind happy. It's also documentation of _what_ we're trusting
240 exit() to clean up for us. But new infrastructure to auto-free stuff would
241 render the existing FEATURE_CLEAN_UP code redundant.
243 For right now, exit() handles it just fine.
247 watchdog.c could autodetect the timer duration via:
248 if(!ioctl (fd, WDIOC_GETTIMEOUT, &tmo)) timer_duration = 1 + (tmo / 2);
249 Unfortunately, that needs linux/watchdog.h and that contains unfiltered
250 kernel types on some distros, which breaks the build.
252 use bb_error_msg where appropriate: See
253 egrep "(printf.*\([[:space:]]*(stderr|2)|[^_]write.*\([[:space:]]*(stderr|2))"
255 use bb_perror_msg where appropriate: See
258 possible code duplication ingroup() and is_a_group_member()
260 Move __get_hz() to a better place and (re)use it in route.c, ash.c
263 Alot of duplication that wants cleanup.
265 in_ether duplicated in network/{interface,ifconfig}.c
267 unify progress_meter. wget, flash_eraseall, pipe_progress, fbsplash, setfiles.
269 support start-stop-daemon -d <chdir-path>
273 Replace deprecated functions.
276 vdprintf() -> similar sized functionality
279 (TODO list after discussion 11.05.2009)
282 tc/brctl seem like fairly large things to try and tackle in your timeframe,
283 and i think people have posted attempts in the past. Adding additional
284 options to ip though seems reasonable.
286 * add tests for some applets
288 * implement POSIX utilities and audit them for POSIX conformance. then
289 audit them for GNU conformance. then document all your findings in a new
290 doc/conformance.txt file while perhaps implementing some of the missing
292 you can find the latest POSIX documentation (1003.1-2008) here:
293 http://www.opengroup.org/onlinepubs/9699919799/
294 and the complete list of all utilities that POSIX covers:
295 http://www.opengroup.org/onlinepubs/9699919799/idx/utilities.html
296 The first step would to generate a file/matrix what is already archived
299 * ntpdate/ntpd (see ntpclient and openntp for examples)
303 * rpcbind (former portmap) or equivalent
304 so that we don't have to use -o nolock on nfs mounts
306 * check IPV6 compliance
308 * generate a mini example using kernel+busybox only (+libc) for example
310 * more support for advanced linux 2.6.x features, see: iotop
311 most likely there is more
313 * even more support for statistics: mpstat, iostat, powertop....
318 Unicode support uses libc multibyte functions if LOCALE_SUPPORT is on
319 (in this case, the code will also support many more encodings),
320 or uses a limited subset of re-implemented multibyte functions
321 which only understand "one byte == one char" and unicode.
322 This is useful if you build against uclibc with locale support disabled.
324 Unicode-dependent applets must call check_unicode_in_env() when they
327 Applet code may conditionalize on UNICODE_SUPPORT in order to use
328 more efficient code if unicode support is not requested.
330 Available functions (if you need more, implement them in libbb/unicode.c
331 so that they work without LOCALE_SUPPORT too):
333 int bb_mbstrlen(str) - multibyte-aware strlen
334 size_t mbstowcs(wdest, src, n)
335 size_t wcstombs(dest, wsrc, n)
336 size_t wcrtomb(str, wc, wstate)
341 Applets which only need to align columns on screen correctly:
343 ls - already done, use source as an example
348 Applets which need to account for Unicode chars
349 while processing the output:
355 cut (-b and -c are currently the same, needs fixing)
357 These applets need to ensure that unicode input
358 is handled correctly (say, <unicode><backspace> sequence):
362 unzip (overwrite prompt)
364 Viewers/editors are more difficult (many cases to get right).
365 libbb/lineedit.c is an example how to do it:
372 Probably needs some specialized work: