+Bernhard Fischer <busybox@busybox.net> suggests to look at these:
+ New debug options:
+ -Wlarger-than-127
+ Cleanup any big users
+ -Wunused-parameter
+ Facilitate applet PROTOTYPES to provide means for having applets that
+ do a) not take any arguments b) need only one of argc or argv c) need
+ both argc and argv. All of these three options should go for the most
+ feature complete denominator.
+ Collate BUFSIZ IOBUF_SIZE MY_BUF_SIZE PIPE_PROGRESS_SIZE BUFSIZE PIPESIZE
+ make bb_common_bufsiz1 configurable, size wise.
+ make pipesize configurable, size wise.
+ Use bb_common_bufsiz1 throughout applets!
+ Add chrt applet. Please CC Bernhard if you suggest a patch.
+
+As yet unclaimed:
+
+----
+find
+ doesn't understand (), lots of susv3 stuff.
+----
+diff
+ Make sure we handle empty files properly:
+ From the patch man page:
+
+ you can remove a file by sending out a context diff that compares
+ the file to be deleted with an empty file dated the Epoch. The
+ file will be removed unless patch is conforming to POSIX and the
+ -E or --remove-empty-files option is not given.
+---
+patch
+ Should have simple fuzz factor support to apply patches at an offset which
+ shouldn't take up too much space.
+
+ And while we're at it, a new patch filename quoting format is apparently
+ coming soon: http://marc.theaimsgroup.com/?l=git&m=112927316408690&w=2
+---
+man
+ It would be nice to have a man command. Not one that handles troff or
+ anything, just one that can handle preformatted ascii man pages, possibly
+ compressed. This could probably be a script in the extras directory that
+ calls cat/zcat/bzcat | less
+
+ (How doclifter might work into this is anybody's guess.)
+---
+ar
+ Write support?
+---
+
+Architectural issues:
+
+bb_close() with fsync()
+ We should have a bb_close() in place of normal close, with a CONFIG_ option
+ to not just check the return value of close() for an error, but fsync().
+ Close can't reliably report anything useful because if write() accepted the
+ data then it either went out to the network or it's in cache or a pipe
+ buffer. Either way, there's no guarantee it'll make it to its final
+ destination before close() gets called, so there's no guarantee that any
+ error will be reported.
+
+ You need to call fsync() if you care about errors that occur after write(),
+ but that can have a big performance impact. So make it a config option.
+---
+Unify archivers
+ Lots of archivers have the same general infrastructure. The directory
+ traversal code should be factored out, and the guts of each archiver could
+ be some setup code and a series of callbacks for "add this file",
+ "add this directory", "add this symlink" and so on.
+
+ This could clean up tar and zip, and make it cheaper to add cpio and ar
+ write support, and possibly even cheaply add things like mkisofs or
+ mksquashfs someday, if they become relevant.
+---
+Text buffer support.
+ Several existing applets (sort, vi, less...) read
+ a whole file into memory and act on it. There might be an opportunity
+ for shared code in there that could be moved into libbb...
+---
+Memory Allocation
+ We have a CONFIG_BUFFER mechanism that lets us select whether to do memory
+ allocation on the stack or the heap. Unfortunately, we're not using it much.
+ We need to audit our memory allocations and turn a lot of malloc/free calls
+ into RESERVE_CONFIG_BUFFER/RELEASE_CONFIG_BUFFER.
+ For a start, see e.g. make EXTRA_CFLAGS=-Wlarger-than-64
+
+ And while we're at it, many of the CONFIG_FEATURE_CLEAN_UP #ifdefs will be
+ optimized out by the compiler in the stack allocation case (since there's no
+ free for an alloca()), and this means that various cleanup loops that just
+ call free might also be optimized out by the compiler if written right, so
+ we can yank those #ifdefs too, and generally clean up the code.
+---
+Switch CONFIG_SYMBOLS to ENABLE_SYMBOLS
+
+ In busybox 1.0 and earlier, configuration was done by CONFIG_SYMBOLS
+ that were either defined or undefined to indicate whether the symbol was
+ selected in the .config file. They were used with #ifdefs, ala:
+
+ #ifdef CONFIG_SYMBOL
+ if (other_test) {
+ do_code();
+ }
+ #endif
+
+ In 1.1, we have new ENABLE_SYMBOLS which are always defined (as 0 or 1),
+ meaning you can still use them for preprocessor tests by replacing
+ "#ifdef CONFIG_SYMBOL" with "#if ENABLE_SYMBOL". But more importantly, we
+ can use them as a true or false test in normal C code:
+
+ if (ENABLE_SYMBOL && other_test) {
+ do_code();
+ }
+
+ (Optimizing away if() statements that resolve to a constant value
+ is known as "dead code elimination", an optimization so old and simple that
+ Turbo Pascal for DOS did it twenty years ago. Even modern mini-compilers
+ like the Tiny C Compiler (tcc) and the Small Device C Compiler (SDCC)
+ perform dead code elimination.)
+
+ Right now, busybox.h is #including both "config.h" (defining the
+ CONFIG_SYMBOLS) and "bb_config.h" (defining the ENABLE_SYMBOLS). At some
+ point in the future, it would be nice to wean ourselves off of the
+ CONFIG versions. (Among other things, some defective build environments
+ leak the Linux kernel's CONFIG_SYMBOLS into the system's standard #include
+ files. We've experienced collisions before.)
+---
+FEATURE_CLEAN_UP
+ This is more an unresolved issue than a to-do item. More thought is needed.
+
+ Normally we rely on exit() to free memory, close files, and unmap segments
+ for us. This makes most calls to free(), close(), and unmap() optional in
+ busybox applets that don't intend to run for very long, and optional stuff
+ can be omitted to save size.
+
+ The idea was raised that we could simulate fork/exit with setjmp/longjmp
+ for _really_ brainless embedded systems, or speed up the standalone shell
+ by not forking. Doing so would require a reliable FEATURE_CLEAN_UP.
+ Unfortunately, this isn't as easy as it sounds.
+
+ The problem is, lots of things exit(), sometimes unexpectedly (xmalloc())
+ and sometimes reliably (bb_perror_msg_and_die() or show_usage()). This
+ jumps out of the normal flow control and bypasses any cleanup code we
+ put at the end of our applets.
+
+ It's possible to add hooks to libbb functions like xmalloc() and xopen()
+ to add their entries to a linked list, which could be traversed and
+ freed/closed automatically. (This would need to be able to free just the
+ entries after a checkpoint to be usable for a forkless standalone shell.
+ You don't want to free the shell's own resources.)
+
+ Right now, FEATURE_CLEAN_UP is more or less a debugging aid, to make things
+ like valgrind happy. It's also documentation of _what_ we're trusting
+ exit() to clean up for us. But new infrastructure to auto-free stuff would
+ render the existing FEATURE_CLEAN_UP code redundant.
+
+ For right now, exit() handles it just fine.
+
+
+
+Minor stuff:
+ watchdog.c could autodetect the timer duration via:
+ if(!ioctl (fd, WDIOC_GETTIMEOUT, &tmo)) timer_duration = 1 + (tmo / 2);
+ Unfortunately, that needs linux/watchdog.h and that contains unfiltered
+ kernel types on some distros, which breaks the build.
+---
+ use bb_error_msg where appropriate: See
+ egrep "(printf.*\([[:space:]]*(stderr|2)|[^_]write.*\([[:space:]]*(stderr|2))"
+---
+ use bb_perror_msg where appropriate: See
+ egrep "[^_]perror"
+---
+ Remove superfluous fmt occurances: e.g.
+ fprintf(stderr, "%s: %s not found\n", "unalias", *argptr);
+ -> fprintf(stderr, "unalias: %s not found\n", *argptr);
+---
+ possible code duplication ingroup() and is_a_group_member()
+---
+ Move __get_hz() to a better place and (re)use it in route.c, ash.c, msh.c
+---
+
+
+Code cleanup:
+
+Replace deprecated functions.
+
+bzero() -> memset()
+---
+sigblock(), siggetmask(), sigsetmask(), sigmask() -> sigprocmask et al
+---
+vdprintf() -> similar sized functionality
+---