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 <rob@landley.net>:
10 Add BB_NOMMU to platform.h and migrate __uClinux__ tests to that.
11 #if defined __UCLIBC__ && !defined __ARCH_USE_MMU__
12 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.
17 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.
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.
30 Compression-side support.
32 General cleanup (should use ENABLE_FEATURE_INIT_SYSLOG and ENABLE_FEATURE_INIT_DEBUG).
33 Unify base64 handling.
34 There's base64 encoding and decoding going on in:
35 networking/wget.c:base64enc()
36 coreutils/uudecode.c:read_base64()
37 coreutils/uuencode.c:tbl_base64[]
38 networking/httpd.c:decodeBase64()
39 And probably elsewhere. That needs to be unified into libbb functions.
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.
46 Even better would be some kind of automated compliance test harness that
47 exercises each command line option and the various corner cases.
49 How much internationalization should we do?
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?)
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.
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?)
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"?)
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
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.
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
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.)
97 One example of an existing system that does this already is Firmware Linux:
98 http://www.landley.net/code/firmware
100 Busybox should have a sample initramfs build script. This depends on
101 bbsh, mdev, and switch_root.
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...
115 Bernhard Fischer <rep.nop@anon.at>:
117 make -j is broken, -j1 is forced atm
120 Collate BUFSIZ IOBUF_SIZE MY_BUF_SIZE PIPE_PROGRESS_SIZE BUFSIZE PIPESIZE
121 Use bb_common_bufsiz1?
127 doesn't understand (), lots of susv3 stuff.
130 Make sure we handle empty files properly:
131 From the patch man page:
133 you can remove a file by sending out a context diff that compares
134 the file to be deleted with an empty file dated the Epoch. The
135 file will be removed unless patch is conforming to POSIX and the
136 -E or --remove-empty-files option is not given.
139 Should have simple fuzz factor support to apply patches at an offset which
140 shouldn't take up too much space.
142 And while we're at it, a new patch filename quoting format is apparently
143 coming soon: http://marc.theaimsgroup.com/?l=git&m=112927316408690&w=2
146 It would be nice to have a man command. Not one that handles troff or
147 anything, just one that can handle preformatted ascii man pages, possibly
148 compressed. This could probably be a script in the extras directory that
149 calls cat/zcat/bzcat | less
151 (How doclifter might work into this is anybody's guess.)
157 turn FEATURE_DEBUG_OPT into ENABLE_FEATURE_CROND_DEBUG_OPT
159 Architectural issues:
161 bb_close() with fsync()
162 We should have a bb_close() in place of normal close, with a CONFIG_ option
163 to not just check the return value of close() for an error, but fsync().
164 Close can't reliably report anything useful because if write() accepted the
165 data then it either went out to the network or it's in cache or a pipe
166 buffer. Either way, there's no guarantee it'll make it to its final
167 destination before close() gets called, so there's no guarantee that any
168 error will be reported.
170 You need to call fsync() if you care about errors that occur after write(),
171 but that can have a big performance impact. So make it a config option.
174 Lots of archivers have the same general infrastructure. The directory
175 traversal code should be factored out, and the guts of each archiver could
176 be some setup code and a series of callbacks for "add this file",
177 "add this directory", "add this symlink" and so on.
179 This could clean up tar and zip, and make it cheaper to add cpio and ar
180 write support, and possibly even cheaply add things like mkisofs or
181 mksquashfs someday, if they become relevant.
184 Several existing applets (sort, vi, less...) read
185 a whole file into memory and act on it. There might be an opportunity
186 for shared code in there that could be moved into libbb...
189 We have a CONFIG_BUFFER mechanism that lets us select whether to do memory
190 allocation on the stack or the heap. Unfortunately, we're not using it much.
191 We need to audit our memory allocations and turn a lot of malloc/free calls
192 into RESERVE_CONFIG_BUFFER/RELEASE_CONFIG_BUFFER.
193 For a start, see e.g. make EXTRA_CFLAGS=-Wlarger-than-64
195 And while we're at it, many of the CONFIG_FEATURE_CLEAN_UP #ifdefs will be
196 optimized out by the compiler in the stack allocation case (since there's no
197 free for an alloca()), and this means that various cleanup loops that just
198 call free might also be optimized out by the compiler if written right, so
199 we can yank those #ifdefs too, and generally clean up the code.
201 Switch CONFIG_SYMBOLS to ENABLE_SYMBOLS
203 In busybox 1.0 and earlier, configuration was done by CONFIG_SYMBOLS
204 that were either defined or undefined to indicate whether the symbol was
205 selected in the .config file. They were used with #ifdefs, ala:
213 In 1.1, we have new ENABLE_SYMBOLS which are always defined (as 0 or 1),
214 meaning you can still use them for preprocessor tests by replacing
215 "#ifdef CONFIG_SYMBOL" with "#if ENABLE_SYMBOL". But more importantly, we
216 can use them as a true or false test in normal C code:
218 if (ENABLE_SYMBOL && other_test) {
222 (Optimizing away if() statements that resolve to a constant value
223 is known as "dead code elimination", an optimization so old and simple that
224 Turbo Pascal for DOS did it twenty years ago. Even modern mini-compilers
225 like the Tiny C Compiler (tcc) and the Small Device C Compiler (SDCC)
226 perform dead code elimination.)
228 Right now, busybox.h is #including both "config.h" (defining the
229 CONFIG_SYMBOLS) and "bb_config.h" (defining the ENABLE_SYMBOLS). At some
230 point in the future, it would be nice to wean ourselves off of the
231 CONFIG versions. (Among other things, some defective build environments
232 leak the Linux kernel's CONFIG_SYMBOLS into the system's standard #include
233 files. We've experienced collisions before.)
236 This is more an unresolved issue than a to-do item. More thought is needed.
238 Normally we rely on exit() to free memory, close files, and unmap segments
239 for us. This makes most calls to free(), close(), and unmap() optional in
240 busybox applets that don't intend to run for very long, and optional stuff
241 can be omitted to save size.
243 The idea was raised that we could simulate fork/exit with setjmp/longjmp
244 for _really_ brainless embedded systems, or speed up the standalone shell
245 by not forking. Doing so would require a reliable FEATURE_CLEAN_UP.
246 Unfortunately, this isn't as easy as it sounds.
248 The problem is, lots of things exit(), sometimes unexpectedly (xmalloc())
249 and sometimes reliably (bb_perror_msg_and_die() or show_usage()). This
250 jumps out of the normal flow control and bypasses any cleanup code we
251 put at the end of our applets.
253 It's possible to add hooks to libbb functions like xmalloc() and bb_xopen()
254 to add their entries to a linked list, which could be traversed and
255 freed/closed automatically. (This would need to be able to free just the
256 entries after a checkpoint to be usable for a forkless standalone shell.
257 You don't want to free the shell's own resources.)
259 Right now, FEATURE_CLEAN_UP is more or less a debugging aid, to make things
260 like valgrind happy. It's also documentation of _what_ we're trusting
261 exit() to clean up for us. But new infrastructure to auto-free stuff would
262 render the existing FEATURE_CLEAN_UP code redundant.
264 For right now, exit() handles it just fine.
269 watchdog.c could autodetect the timer duration via:
270 if(!ioctl (fd, WDIOC_GETTIMEOUT, &tmo)) timer_duration = 1 + (tmo / 2);
271 Unfortunately, that needs linux/watchdog.h and that contains unfiltered
272 kernel types on some distros, which breaks the build.
274 use bb_error_msg where appropriate: See
275 egrep "(printf.*\([[:space:]]*(stderr|2)|[^_]write.*\([[:space:]]*(stderr|2))"
277 use bb_perror_msg where appropriate: See
280 Remove superfluous fmt occurances: e.g.
281 fprintf(stderr, "%s: %s not found\n", "unalias", *argptr);
282 -> fprintf(stderr, "unalias: %s not found\n", *argptr);
284 possible code duplication ingroup() and is_a_group_member()
286 unify itoa: netstat.c, hush.c, lash.c, msh.c
287 Put one single, robust version into e.g. safe_strtol.c
293 Replace deprecated functions.
297 sigblock(), siggetmask(), sigsetmask(), sigmask() -> sigprocmask et al
299 vdprintf() -> similar sized functionality