blob: 10ed7e0d53f14600ca2ce86a9accd68652607452 [file] [log] [blame]
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
Rob Landleydf4cdaf2006-05-19 20:47:55 +00009Rob Landley <rob@landley.net>:
Rob Landley4b146e62006-05-30 18:31:37 +000010 Add BB_NOMMU to platform.h and migrate __uClinux__ tests to that.
11 #if defined __UCLIBC__ && !defined __ARCH_USE_MMU__
Rob Landley0582ee02006-05-29 05:06:06 +000012 Add a libbb/platform.c
13 Implement fdprintf() for platforms that haven't got one.
14 Implement bb_realpath() that can handle NULL on non-glibc.
15 Cleanup bb_asprintf()
16
Rob Landleydf4cdaf2006-05-19 20:47:55 +000017 Migrate calloc() and bb_calloc() occurrences to bb_xzalloc().
18 Remove obsolete _() wrapper crud for internationalization we don't do.
19 Figure out where we need utf8 support, and add it.
20
21 sh
22 The command shell situation is a big mess. We have three or four different
23 shells that don't really share any code, and the "standalone shell" doesn't
24 work all that well (especially not in a chroot environment), due to apps not
25 being reentrant. I'm writing a new shell (bbsh) to unify the various
26 shells and configurably add the minimal set of bash features people
27 actually use. The hardest part is it has to configure down as small as
28 lash while providing lash's features. The rest is easy in comparison.
29 bzip2
30 Compression-side support.
31 init
Bernhard Reutner-Fischer0da069d2006-05-29 12:54:16 +000032 General cleanup (should use ENABLE_FEATURE_INIT_SYSLOG and ENABLE_FEATURE_INIT_DEBUG).
Ned Ludd5df6d9f2006-06-30 21:48:38 +000033 depmod
34 busybox lacks a way to update module deps when running from firmware without the
35 use of the depmod.pl (perl is to bloated for most embedded setups) and or orig
Denis Vlasenko9213a9e2006-09-17 16:28:10 +000036 modutils. The orig depmod is rather pointless to have to add to a firmware image
Ned Ludd5df6d9f2006-06-30 21:48:38 +000037 in when we already have a insmod/rmmod and friends.
Rob Landleydf4cdaf2006-05-19 20:47:55 +000038 Unify base64 handling.
Denis Vlasenko088b9592007-04-18 21:14:46 +000039 [done]
Rob Landleydf4cdaf2006-05-19 20:47:55 +000040 Do a SUSv3 audit
41 Look at the full Single Unix Specification version 3 (available online at
42 "http://www.opengroup.org/onlinepubs/009695399/nfindex.html") and
43 figure out which of our apps are compliant, and what we're missing that
44 we might actually care about.
45
46 Even better would be some kind of automated compliance test harness that
47 exercises each command line option and the various corner cases.
48 Internationalization
49 How much internationalization should we do?
50
51 The low hanging fruit is UTF-8 character set support. We should do this.
52 (Vodz pointed out the shell's cmdedit as needing work here. What else?)
53
54 We also have lots of hardwired english text messages. Consolidating this
55 into some kind of message table not only makes translation easier, but
56 also allows us to consolidate redundant (or close) strings.
57
58 We probably don't want to be bloated with locale support. (Not unless we
59 can cleanly export it from our underlying C library without having to
60 concern ourselves with it directly. Perhaps a few specific things like a
61 config option for "date" are low hanging fruit here?)
62
63 What level should things happen at? How much do we care about
64 internationalizing the text console when X11 and xterms are so much better
65 at it? (There's some infrastructure here we don't implement: The
66 "unicode_start" and "unicode_stop" shell scripts need "vt-is-UTF8" and a
67 --unicode option to loadkeys. That implies a real loadkeys/dumpkeys
68 implementation to replace loadkmap/dumpkmap. Plus messing with console font
69 loading. Is it worth it, or do we just say "use X"?)
70
71 Individual compilation of applets.
72 It would be nice if busybox had the option to compile to individual applets,
73 for people who want an alternate implementation less bloated than the gnu
74 utils (or simply with less political baggage), but without it being one big
75 executable.
76
77 Turning libbb into a real dll is another possibility, especially if libbb
78 could export some of the other library interfaces we've already more or less
79 got the code for (like zlib).
80 buildroot - Make a "dogfood" option
81 Busybox 1.1 will be capable of replacing most gnu packages for real world
82 use, such as developing software or in a live CD. It needs wider testing.
83
84 Busybox should now be able to replace bzip2, coreutils, e2fsprogs, file,
85 findutils, gawk, grep, inetutils, less, modutils, net-tools, patch, procps,
86 sed, shadow, sysklogd, sysvinit, tar, util-linux, and vim. The resulting
87 system should be self-hosting (I.E. able to rebuild itself from source
88 code). This means it would need (at least) binutils, gcc, and make, or
89 equivalents.
90
91 It would be a good "eating our own dogfood" test if buildroot had the option
92 of using a "make allyesconfig" busybox instead of the all of the above
93 packages. Anything that's wrong with the resulting system, we can fix. (It
94 would be nice to be able to upgrade busybox to be able to replace bash and
95 diffutils as well, but we're not there yet.)
96
97 One example of an existing system that does this already is Firmware Linux:
98 http://www.landley.net/code/firmware
99 initramfs
100 Busybox should have a sample initramfs build script. This depends on
101 bbsh, mdev, and switch_root.
Rob Landley9c0e4f02006-06-30 16:38:09 +0000102 mkdep
103 Write a mkdep that doesn't segfault if there's a directory it doesn't
104 have permission to read, isn't based on manually editing the output of
105 lexx and yacc, doesn't make such a mess under include/config, etc.
106 Group globals into unions of structures.
107 Go through and turn all the global and static variables into structures,
108 and have all those structures be in a big union shared between processes,
109 so busybox uses less bss. (This is a big win on nommu machines.) See
110 sed.c and mdev.c for examples.
111 Go through bugs.busybox.net and close out all of that somehow.
112 This one's open to everybody, but I'll wind up doing it...
Rob Landleydf4cdaf2006-05-19 20:47:55 +0000113
114
Bernhard Reutner-Fischer05592ac2006-09-21 22:58:38 +0000115Bernhard Fischer <busybox@busybox.net> suggests to look at these:
Rob Landley0582ee02006-05-29 05:06:06 +0000116 New debug options:
117 -Wlarger-than-127
Bernhard Reutner-Fischer05592ac2006-09-21 22:58:38 +0000118 Cleanup any big users
119 -Wunused-parameter
120 Facilitate applet PROTOTYPES to provide means for having applets that
121 do a) not take any arguments b) need only one of argc or argv c) need
122 both argc and argv. All of these three options should go for the most
123 feature complete denominator.
Rob Landley0582ee02006-05-29 05:06:06 +0000124 Collate BUFSIZ IOBUF_SIZE MY_BUF_SIZE PIPE_PROGRESS_SIZE BUFSIZE PIPESIZE
Bernhard Reutner-Fischer05592ac2006-09-21 22:58:38 +0000125 make bb_common_bufsiz1 configurable, size wise.
126 make pipesize configurable, size wise.
127 Use bb_common_bufsiz1 throughout applets!
Rob Landleydf4cdaf2006-05-19 20:47:55 +0000128
129As yet unclaimed:
130
Mike Frysingerb38673f2006-02-02 01:41:53 +0000131----
Rob Landleyf4bb2122005-01-24 06:56:24 +0000132find
Rob Landleyc58fd152005-10-25 20:22:50 +0000133 doesn't understand (), lots of susv3 stuff.
Rob Landleyf4bb2122005-01-24 06:56:24 +0000134----
Rob Landleyf4bb2122005-01-24 06:56:24 +0000135diff
Rob Landleydf4cdaf2006-05-19 20:47:55 +0000136 Make sure we handle empty files properly:
Rob Landley8bcc6e92006-01-09 00:54:46 +0000137 From the patch man page:
138
Mike Frysinger0b7dfb52006-07-27 03:42:30 +0000139 you can remove a file by sending out a context diff that compares
140 the file to be deleted with an empty file dated the Epoch. The
141 file will be removed unless patch is conforming to POSIX and the
142 -E or --remove-empty-files option is not given.
Rob Landleyf4bb2122005-01-24 06:56:24 +0000143---
144patch
Rob Landleyc9c959c2005-10-27 00:57:50 +0000145 Should have simple fuzz factor support to apply patches at an offset which
Rob Landley078bacf2005-09-01 03:02:23 +0000146 shouldn't take up too much space.
Rob Landleyc9c959c2005-10-27 00:57:50 +0000147
148 And while we're at it, a new patch filename quoting format is apparently
149 coming soon: http://marc.theaimsgroup.com/?l=git&m=112927316408690&w=2
Rob Landleyf4bb2122005-01-24 06:56:24 +0000150---
Mike Frysinger0aa6ba52007-02-08 08:21:58 +0000151ps / top
152 Add support for both RSS and VSIZE rather than just one or the other.
153 Or make it a build option.
154---
Rob Landleyf4bb2122005-01-24 06:56:24 +0000155man
156 It would be nice to have a man command. Not one that handles troff or
157 anything, just one that can handle preformatted ascii man pages, possibly
158 compressed. This could probably be a script in the extras directory that
Rob Landleyc58fd152005-10-25 20:22:50 +0000159 calls cat/zcat/bzcat | less
Rob Landley8bcc6e92006-01-09 00:54:46 +0000160
161 (How doclifter might work into this is anybody's guess.)
Rob Landleyf4bb2122005-01-24 06:56:24 +0000162---
Rob Landley8bcc6e92006-01-09 00:54:46 +0000163ar
164 Write support?
Bernhard Reutner-Fischer24efe4f2007-04-04 17:57:55 +0000165---
Bernhard Reutner-Fischerae114c22007-01-17 19:51:00 +0000166stty / catv
167 stty's visible() function and catv's guts are identical. Merge them into
168 an appropriate libbb function.
Bernhard Reutner-Fischer24efe4f2007-04-04 17:57:55 +0000169---
Bernhard Reutner-Fischer7b1c5aa2007-01-24 21:13:16 +0000170struct suffix_mult
171 Several duplicate users of: grep -r "1024\*1024" * -B2 -A1
172 Merge to a single size_suffixes[] in libbb.
173 Users: head tail od_bloaty hexdump and (partially as it wouldn't hurt) svlogd
Bernhard Reutner-Fischer24efe4f2007-04-04 17:57:55 +0000174---
175tail
176 ./busybox tail -f foo.c~ TODO
177 should not print fmt=header_fmt for subsequent date >> TODO; i.e. only
178 fmt+ if another (not the current) file did change
Rob Landleyf4bb2122005-01-24 06:56:24 +0000179
180Architectural issues:
181
Rob Landley7b7c99c2005-11-04 20:45:54 +0000182bb_close() with fsync()
183 We should have a bb_close() in place of normal close, with a CONFIG_ option
184 to not just check the return value of close() for an error, but fsync().
185 Close can't reliably report anything useful because if write() accepted the
Rob Landley8bcc6e92006-01-09 00:54:46 +0000186 data then it either went out to the network or it's in cache or a pipe
187 buffer. Either way, there's no guarantee it'll make it to its final
188 destination before close() gets called, so there's no guarantee that any
189 error will be reported.
190
Rob Landley7b7c99c2005-11-04 20:45:54 +0000191 You need to call fsync() if you care about errors that occur after write(),
192 but that can have a big performance impact. So make it a config option.
193---
Rob Landleyf4bb2122005-01-24 06:56:24 +0000194Unify archivers
195 Lots of archivers have the same general infrastructure. The directory
196 traversal code should be factored out, and the guts of each archiver could
197 be some setup code and a series of callbacks for "add this file",
198 "add this directory", "add this symlink" and so on.
199
200 This could clean up tar and zip, and make it cheaper to add cpio and ar
Rob Landley8bcc6e92006-01-09 00:54:46 +0000201 write support, and possibly even cheaply add things like mkisofs or
202 mksquashfs someday, if they become relevant.
Rob Landleyf4bb2122005-01-24 06:56:24 +0000203---
204Text buffer support.
Rob Landleyc58fd152005-10-25 20:22:50 +0000205 Several existing applets (sort, vi, less...) read
Rob Landleyf4bb2122005-01-24 06:56:24 +0000206 a whole file into memory and act on it. There might be an opportunity
207 for shared code in there that could be moved into libbb...
208---
Rob Landley958fa2a2005-06-11 22:10:42 +0000209Memory Allocation
210 We have a CONFIG_BUFFER mechanism that lets us select whether to do memory
211 allocation on the stack or the heap. Unfortunately, we're not using it much.
212 We need to audit our memory allocations and turn a lot of malloc/free calls
213 into RESERVE_CONFIG_BUFFER/RELEASE_CONFIG_BUFFER.
Rob Landley1fa4a942006-06-22 22:05:00 +0000214 For a start, see e.g. make EXTRA_CFLAGS=-Wlarger-than-64
Rob Landleya8821262005-09-16 14:58:55 +0000215
Rob Landley958fa2a2005-06-11 22:10:42 +0000216 And while we're at it, many of the CONFIG_FEATURE_CLEAN_UP #ifdefs will be
217 optimized out by the compiler in the stack allocation case (since there's no
218 free for an alloca()), and this means that various cleanup loops that just
219 call free might also be optimized out by the compiler if written right, so
220 we can yank those #ifdefs too, and generally clean up the code.
Rob Landleya8821262005-09-16 14:58:55 +0000221---
222Switch CONFIG_SYMBOLS to ENABLE_SYMBOLS
223
224 In busybox 1.0 and earlier, configuration was done by CONFIG_SYMBOLS
225 that were either defined or undefined to indicate whether the symbol was
226 selected in the .config file. They were used with #ifdefs, ala:
227
228 #ifdef CONFIG_SYMBOL
229 if (other_test) {
230 do_code();
231 }
232 #endif
233
234 In 1.1, we have new ENABLE_SYMBOLS which are always defined (as 0 or 1),
235 meaning you can still use them for preprocessor tests by replacing
236 "#ifdef CONFIG_SYMBOL" with "#if ENABLE_SYMBOL". But more importantly, we
237 can use them as a true or false test in normal C code:
238
239 if (ENABLE_SYMBOL && other_test) {
240 do_code();
241 }
242
243 (Optimizing away if() statements that resolve to a constant value
244 is known as "dead code elimination", an optimization so old and simple that
245 Turbo Pascal for DOS did it twenty years ago. Even modern mini-compilers
246 like the Tiny C Compiler (tcc) and the Small Device C Compiler (SDCC)
247 perform dead code elimination.)
248
249 Right now, busybox.h is #including both "config.h" (defining the
250 CONFIG_SYMBOLS) and "bb_config.h" (defining the ENABLE_SYMBOLS). At some
251 point in the future, it would be nice to wean ourselves off of the
252 CONFIG versions. (Among other things, some defective build environments
253 leak the Linux kernel's CONFIG_SYMBOLS into the system's standard #include
254 files. We've experienced collisions before.)
255---
256FEATURE_CLEAN_UP
257 This is more an unresolved issue than a to-do item. More thought is needed.
258
259 Normally we rely on exit() to free memory, close files, and unmap segments
260 for us. This makes most calls to free(), close(), and unmap() optional in
261 busybox applets that don't intend to run for very long, and optional stuff
262 can be omitted to save size.
263
264 The idea was raised that we could simulate fork/exit with setjmp/longjmp
265 for _really_ brainless embedded systems, or speed up the standalone shell
266 by not forking. Doing so would require a reliable FEATURE_CLEAN_UP.
267 Unfortunately, this isn't as easy as it sounds.
268
269 The problem is, lots of things exit(), sometimes unexpectedly (xmalloc())
270 and sometimes reliably (bb_perror_msg_and_die() or show_usage()). This
271 jumps out of the normal flow control and bypasses any cleanup code we
272 put at the end of our applets.
273
Bernhard Reutner-Fischer8c1eda52006-08-28 23:39:36 +0000274 It's possible to add hooks to libbb functions like xmalloc() and xopen()
Rob Landleya8821262005-09-16 14:58:55 +0000275 to add their entries to a linked list, which could be traversed and
276 freed/closed automatically. (This would need to be able to free just the
277 entries after a checkpoint to be usable for a forkless standalone shell.
278 You don't want to free the shell's own resources.)
279
280 Right now, FEATURE_CLEAN_UP is more or less a debugging aid, to make things
281 like valgrind happy. It's also documentation of _what_ we're trusting
282 exit() to clean up for us. But new infrastructure to auto-free stuff would
283 render the existing FEATURE_CLEAN_UP code redundant.
284
285 For right now, exit() handles it just fine.
Rob Landley8bcc6e92006-01-09 00:54:46 +0000286
287
288
289Minor stuff:
290 watchdog.c could autodetect the timer duration via:
291 if(!ioctl (fd, WDIOC_GETTIMEOUT, &tmo)) timer_duration = 1 + (tmo / 2);
292 Unfortunately, that needs linux/watchdog.h and that contains unfiltered
293 kernel types on some distros, which breaks the build.
Bernhard Reutner-Fischer863073d2006-06-04 16:05:02 +0000294---
Bernhard Reutner-Fischer395010b2006-06-04 15:37:59 +0000295 use bb_error_msg where appropriate: See
296 egrep "(printf.*\([[:space:]]*(stderr|2)|[^_]write.*\([[:space:]]*(stderr|2))"
Bernhard Reutner-Fischer863073d2006-06-04 16:05:02 +0000297---
Bernhard Reutner-Fischer395010b2006-06-04 15:37:59 +0000298 use bb_perror_msg where appropriate: See
299 egrep "[^_]perror"
Bernhard Reutner-Fischer863073d2006-06-04 16:05:02 +0000300---
301 Remove superfluous fmt occurances: e.g.
302 fprintf(stderr, "%s: %s not found\n", "unalias", *argptr);
303 -> fprintf(stderr, "unalias: %s not found\n", *argptr);
304---
Bernhard Reutner-Fischer213cc002006-06-04 17:58:19 +0000305 possible code duplication ingroup() and is_a_group_member()
306---
Bernhard Reutner-Fischere02706f2006-07-02 10:33:10 +0000307 Move __get_hz() to a better place and (re)use it in route.c, ash.c, msh.c
308---
Bernhard Reutner-Fischer395010b2006-06-04 15:37:59 +0000309
Bernhard Reutner-Fischer2677cf12006-01-13 08:46:39 +0000310
311Code cleanup:
312
313Replace deprecated functions.
314
315bzero() -> memset()
316---
317sigblock(), siggetmask(), sigsetmask(), sigmask() -> sigprocmask et al
318---
Bernhard Reutner-Fischer34fc71f2006-04-12 18:50:19 +0000319vdprintf() -> similar sized functionality
320---