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Glenn L McGrath90d2bff2004-05-01 00:49:49 +00001Busybox TODO
2
Rob Landleydf4cdaf2006-05-19 20:47:55 +00003Stuff that needs to be done. This is organized by who plans to get around to
4doing it eventually, but that doesn't mean they "own" the item. If you want to
5do one of these bounce an email off the person it's listed under to see if they
6have any suggestions how they plan to go about it, and to minimize conflicts
7between your work and theirs. But otherwise, all of these are fair game.
Glenn L McGrath90d2bff2004-05-01 00:49:49 +00008
Dan Fandrichfe4e23f2009-11-01 04:01:30 +01009Rob Landley suggested this:
10 Implement bb_realpath() that can handle NULL on non-glibc.
Rob Landley0582ee02006-05-29 05:06:06 +000011
Rob Landleydf4cdaf2006-05-19 20:47:55 +000012 Remove obsolete _() wrapper crud for internationalization we don't do.
13 Figure out where we need utf8 support, and add it.
14
15 sh
Denys Vlasenko1cc4b132009-08-21 00:05:51 +020016 The command shell situation is a mess. We have two different
Rob Landleydf4cdaf2006-05-19 20:47:55 +000017 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
Denis Vlasenko96702ca2007-11-23 23:28:55 +000019 being reentrant.
Denys Vlasenko62298ab2009-09-07 13:19:17 +020020
Rob Landleydf4cdaf2006-05-19 20:47:55 +000021 Do a SUSv3 audit
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.
26
27 Even better would be some kind of automated compliance test harness that
28 exercises each command line option and the various corner cases.
Denys Vlasenko62298ab2009-09-07 13:19:17 +020029
Rob Landleydf4cdaf2006-05-19 20:47:55 +000030 Internationalization
31 How much internationalization should we do?
32
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?)
35
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.
39
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?)
44
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"?)
52
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
57 executable.
58
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.
65
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
71 equivalents.
72
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.)
78
79 One example of an existing system that does this already is Firmware Linux:
80 http://www.landley.net/code/firmware
81 initramfs
82 Busybox should have a sample initramfs build script. This depends on
83 bbsh, mdev, and switch_root.
Rob Landley9c0e4f02006-06-30 16:38:09 +000084 mkdep
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...
Rob Landleydf4cdaf2006-05-19 20:47:55 +000095
96
Bernhard Reutner-Fischer6c4dade2008-09-25 12:13:34 +000097Bernhard Reutner-Fischer <busybox@busybox.net> suggests to look at these:
Rob Landley0582ee02006-05-29 05:06:06 +000098 New debug options:
99 -Wlarger-than-127
Bernhard Reutner-Fischer05592ac2006-09-21 22:58:38 +0000100 Cleanup any big users
Rob Landley0582ee02006-05-29 05:06:06 +0000101 Collate BUFSIZ IOBUF_SIZE MY_BUF_SIZE PIPE_PROGRESS_SIZE BUFSIZE PIPESIZE
Bernhard Reutner-Fischer05592ac2006-09-21 22:58:38 +0000102 make bb_common_bufsiz1 configurable, size wise.
103 make pipesize configurable, size wise.
104 Use bb_common_bufsiz1 throughout applets!
Rob Landleydf4cdaf2006-05-19 20:47:55 +0000105
106As yet unclaimed:
107
Mike Frysingerb38673f2006-02-02 01:41:53 +0000108----
Rob Landleyf4bb2122005-01-24 06:56:24 +0000109diff
Rob Landleydf4cdaf2006-05-19 20:47:55 +0000110 Make sure we handle empty files properly:
Rob Landley8bcc6e92006-01-09 00:54:46 +0000111 From the patch man page:
112
Mike Frysinger0b7dfb52006-07-27 03:42:30 +0000113 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.
Rob Landleyf4bb2122005-01-24 06:56:24 +0000117---
118patch
Rob Landleyc9c959c2005-10-27 00:57:50 +0000119 Should have simple fuzz factor support to apply patches at an offset which
Rob Landley078bacf2005-09-01 03:02:23 +0000120 shouldn't take up too much space.
Rob Landleyc9c959c2005-10-27 00:57:50 +0000121
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
Rob Landleyf4bb2122005-01-24 06:56:24 +0000124---
Rob Landley8bcc6e92006-01-09 00:54:46 +0000125ar
Bernhard Reutner-Fischerb6926102008-06-17 07:52:43 +0000126 Write support!
Bernhard Reutner-Fischer24efe4f2007-04-04 17:57:55 +0000127---
Bernhard Reutner-Fischerae114c22007-01-17 19:51:00 +0000128stty / catv
129 stty's visible() function and catv's guts are identical. Merge them into
130 an appropriate libbb function.
Bernhard Reutner-Fischer24efe4f2007-04-04 17:57:55 +0000131---
Bernhard Reutner-Fischer7b1c5aa2007-01-24 21:13:16 +0000132struct suffix_mult
133 Several duplicate users of: grep -r "1024\*1024" * -B2 -A1
134 Merge to a single size_suffixes[] in libbb.
135 Users: head tail od_bloaty hexdump and (partially as it wouldn't hurt) svlogd
Bernhard Reutner-Fischer24efe4f2007-04-04 17:57:55 +0000136---
137tail
138 ./busybox tail -f foo.c~ TODO
139 should not print fmt=header_fmt for subsequent date >> TODO; i.e. only
140 fmt+ if another (not the current) file did change
Rob Landleyf4bb2122005-01-24 06:56:24 +0000141
142Architectural issues:
143
Rob Landley7b7c99c2005-11-04 20:45:54 +0000144bb_close() with fsync()
145 We should have a bb_close() in place of normal close, with a CONFIG_ option
146 to not just check the return value of close() for an error, but fsync().
147 Close can't reliably report anything useful because if write() accepted the
Rob Landley8bcc6e92006-01-09 00:54:46 +0000148 data then it either went out to the network or it's in cache or a pipe
149 buffer. Either way, there's no guarantee it'll make it to its final
150 destination before close() gets called, so there's no guarantee that any
151 error will be reported.
152
Rob Landley7b7c99c2005-11-04 20:45:54 +0000153 You need to call fsync() if you care about errors that occur after write(),
154 but that can have a big performance impact. So make it a config option.
155---
Rob Landleyf4bb2122005-01-24 06:56:24 +0000156Unify archivers
157 Lots of archivers have the same general infrastructure. The directory
158 traversal code should be factored out, and the guts of each archiver could
159 be some setup code and a series of callbacks for "add this file",
160 "add this directory", "add this symlink" and so on.
161
162 This could clean up tar and zip, and make it cheaper to add cpio and ar
Rob Landley8bcc6e92006-01-09 00:54:46 +0000163 write support, and possibly even cheaply add things like mkisofs or
164 mksquashfs someday, if they become relevant.
Rob Landleyf4bb2122005-01-24 06:56:24 +0000165---
166Text buffer support.
Rob Landleyc58fd152005-10-25 20:22:50 +0000167 Several existing applets (sort, vi, less...) read
Bernhard Reutner-Fischere455f6e2009-02-18 14:05:54 +0000168 a whole file into memory and act on it. Use open_read_close().
Rob Landleyf4bb2122005-01-24 06:56:24 +0000169---
Rob Landley958fa2a2005-06-11 22:10:42 +0000170Memory Allocation
171 We have a CONFIG_BUFFER mechanism that lets us select whether to do memory
172 allocation on the stack or the heap. Unfortunately, we're not using it much.
173 We need to audit our memory allocations and turn a lot of malloc/free calls
174 into RESERVE_CONFIG_BUFFER/RELEASE_CONFIG_BUFFER.
Rob Landley1fa4a942006-06-22 22:05:00 +0000175 For a start, see e.g. make EXTRA_CFLAGS=-Wlarger-than-64
Rob Landleya8821262005-09-16 14:58:55 +0000176
Rob Landley958fa2a2005-06-11 22:10:42 +0000177 And while we're at it, many of the CONFIG_FEATURE_CLEAN_UP #ifdefs will be
178 optimized out by the compiler in the stack allocation case (since there's no
179 free for an alloca()), and this means that various cleanup loops that just
180 call free might also be optimized out by the compiler if written right, so
181 we can yank those #ifdefs too, and generally clean up the code.
Rob Landleya8821262005-09-16 14:58:55 +0000182---
183Switch CONFIG_SYMBOLS to ENABLE_SYMBOLS
184
185 In busybox 1.0 and earlier, configuration was done by CONFIG_SYMBOLS
186 that were either defined or undefined to indicate whether the symbol was
187 selected in the .config file. They were used with #ifdefs, ala:
188
189 #ifdef CONFIG_SYMBOL
190 if (other_test) {
191 do_code();
192 }
193 #endif
194
195 In 1.1, we have new ENABLE_SYMBOLS which are always defined (as 0 or 1),
196 meaning you can still use them for preprocessor tests by replacing
197 "#ifdef CONFIG_SYMBOL" with "#if ENABLE_SYMBOL". But more importantly, we
198 can use them as a true or false test in normal C code:
199
200 if (ENABLE_SYMBOL && other_test) {
201 do_code();
202 }
203
204 (Optimizing away if() statements that resolve to a constant value
205 is known as "dead code elimination", an optimization so old and simple that
206 Turbo Pascal for DOS did it twenty years ago. Even modern mini-compilers
207 like the Tiny C Compiler (tcc) and the Small Device C Compiler (SDCC)
208 perform dead code elimination.)
209
210 Right now, busybox.h is #including both "config.h" (defining the
211 CONFIG_SYMBOLS) and "bb_config.h" (defining the ENABLE_SYMBOLS). At some
212 point in the future, it would be nice to wean ourselves off of the
213 CONFIG versions. (Among other things, some defective build environments
214 leak the Linux kernel's CONFIG_SYMBOLS into the system's standard #include
215 files. We've experienced collisions before.)
216---
217FEATURE_CLEAN_UP
218 This is more an unresolved issue than a to-do item. More thought is needed.
219
Bernhard Reutner-Fischer8517d6f2009-03-05 17:27:39 +0000220 Normally we rely on exit() to free memory, close files and unmap segments
Rob Landleya8821262005-09-16 14:58:55 +0000221 for us. This makes most calls to free(), close(), and unmap() optional in
222 busybox applets that don't intend to run for very long, and optional stuff
223 can be omitted to save size.
224
225 The idea was raised that we could simulate fork/exit with setjmp/longjmp
226 for _really_ brainless embedded systems, or speed up the standalone shell
227 by not forking. Doing so would require a reliable FEATURE_CLEAN_UP.
228 Unfortunately, this isn't as easy as it sounds.
229
230 The problem is, lots of things exit(), sometimes unexpectedly (xmalloc())
231 and sometimes reliably (bb_perror_msg_and_die() or show_usage()). This
232 jumps out of the normal flow control and bypasses any cleanup code we
233 put at the end of our applets.
234
Bernhard Reutner-Fischer8c1eda52006-08-28 23:39:36 +0000235 It's possible to add hooks to libbb functions like xmalloc() and xopen()
Rob Landleya8821262005-09-16 14:58:55 +0000236 to add their entries to a linked list, which could be traversed and
237 freed/closed automatically. (This would need to be able to free just the
238 entries after a checkpoint to be usable for a forkless standalone shell.
239 You don't want to free the shell's own resources.)
240
241 Right now, FEATURE_CLEAN_UP is more or less a debugging aid, to make things
242 like valgrind happy. It's also documentation of _what_ we're trusting
243 exit() to clean up for us. But new infrastructure to auto-free stuff would
244 render the existing FEATURE_CLEAN_UP code redundant.
245
246 For right now, exit() handles it just fine.
Rob Landley8bcc6e92006-01-09 00:54:46 +0000247
248
Rob Landley8bcc6e92006-01-09 00:54:46 +0000249Minor stuff:
250 watchdog.c could autodetect the timer duration via:
251 if(!ioctl (fd, WDIOC_GETTIMEOUT, &tmo)) timer_duration = 1 + (tmo / 2);
252 Unfortunately, that needs linux/watchdog.h and that contains unfiltered
253 kernel types on some distros, which breaks the build.
Bernhard Reutner-Fischer863073d2006-06-04 16:05:02 +0000254---
Bernhard Reutner-Fischer395010b2006-06-04 15:37:59 +0000255 use bb_error_msg where appropriate: See
256 egrep "(printf.*\([[:space:]]*(stderr|2)|[^_]write.*\([[:space:]]*(stderr|2))"
Bernhard Reutner-Fischer863073d2006-06-04 16:05:02 +0000257---
Bernhard Reutner-Fischer395010b2006-06-04 15:37:59 +0000258 use bb_perror_msg where appropriate: See
259 egrep "[^_]perror"
Bernhard Reutner-Fischer863073d2006-06-04 16:05:02 +0000260---
Bernhard Reutner-Fischer213cc002006-06-04 17:58:19 +0000261 possible code duplication ingroup() and is_a_group_member()
262---
Denys Vlasenko1cc4b132009-08-21 00:05:51 +0200263 Move __get_hz() to a better place and (re)use it in route.c, ash.c
Bernhard Reutner-Fischere02706f2006-07-02 10:33:10 +0000264---
Bernhard Reutner-Fischerc2f0de52008-01-14 14:32:56 +0000265 See grep -r strtod
266 Alot of duplication that wants cleanup.
267---
Bernhard Reutner-Fischer1b237732008-05-16 14:35:34 +0000268 in_ether duplicated in network/{interface,ifconfig}.c
269---
Bernhard Reutner-Fischere455f6e2009-02-18 14:05:54 +0000270 unify progress_meter. wget, flash_eraseall, pipe_progress, fbsplash, setfiles.
Bernhard Reutner-Fischerae0045e2009-09-17 18:57:21 +0200271---
272 support start-stop-daemon -d <chdir-path>
Bernhard Reutner-Fischer2677cf12006-01-13 08:46:39 +0000273
274Code cleanup:
275
276Replace deprecated functions.
277
Bernhard Reutner-Fischer2677cf12006-01-13 08:46:39 +0000278---
Bernhard Reutner-Fischer34fc71f2006-04-12 18:50:19 +0000279vdprintf() -> similar sized functionality
280---
Denys Vlasenko318a8e52009-05-13 02:18:43 +0200281
282(TODO list after discussion 11.05.2009)
283
284* shrink tc/brctl/ip
285 tc/brctl seem like fairly large things to try and tackle in your timeframe,
Bernhard Reutner-Fischerca4f8d52009-07-03 01:06:15 +0200286 and i think people have posted attempts in the past. Adding additional
Denys Vlasenko318a8e52009-05-13 02:18:43 +0200287 options to ip though seems reasonable.
288
289* add tests for some applets
290
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
294 features.
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
300 (also IPV6)
301
302* ntpdate/ntpd (see ntpclient and openntp for examples)
303
304* implement 'at'
305
306* rpcbind (former portmap) or equivalent
307 so that we don't have to use -o nolock on nfs mounts
308
309* check IPV6 compliance
310
311* generate a mini example using kernel+busybox only (+libc) for example
312
313* more support for advanced linux 2.6.x features, see: iotop
314 most likely there is more
315
316* even more support for statistics: mpstat, iostat, powertop....
Denys Vlasenko62298ab2009-09-07 13:19:17 +0200317
318
319Unicode work needed:
320
Denys Vlasenko00528822009-09-11 23:26:42 +0200321Unicode support uses libc multibyte functions if LOCALE_SUPPORT is on
322(in this case, the code will also support many more encodings),
323or uses a limited subset of re-implemented multibyte functions
324which only understand "one byte == one char" and unicode.
325This is useful if you build against uclibc with locale support disabled.
326
327Unicode-dependent applets must call check_unicode_in_env() when they
328begin executing.
329
330Applet code may conditionalize on FEATURE_ASSUME_UNICODE
331in order to use more efficient code if unicode support is not requested.
332
333Available functions (if you need more, implement them in libbb/unicode.c
334so that they work without LOCALE_SUPPORT too):
335
336int bb_mbstrlen(str) - multibyte-aware strlen
337size_t mbstowcs(wdest, src, n)
338size_t wcstombs(dest, wsrc, n)
339size_t wcrtomb(str, wc, wstate)
340int iswspace(wc)
341int iswalnum(wc)
342int iswpunct(wc)
343
Denys Vlasenko62298ab2009-09-07 13:19:17 +0200344Applets which only need to align columns on screen correctly:
345
346ls - already done, use source as an example
347df
348dumpleases
349lsmod
350
351Applets which need to account for Unicode chars
352while processing the output:
353
354[un]expand
355fold
356man
357watch
358cut (-b and -c are currently the same, needs fixing)
359
360These applets need to ensure that unicode input
361is handled correctly (say, <unicode><backspace> sequence):
362
363getty, login
364rm -i
365unzip (overwrite prompt)
366
367Viewers/editors are more difficult (many cases to get right).
368libbb/lineedit.c is an example how to do it:
369
370less, most, ed, vi
371awk
372[ef]grep
373sed
374
375Probably needs some specialized work:
376
377loadkeys