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