If you're interested in helping, here are some tasks that we've considered over the years. Beware: some are quite old and no longer valid. To avoid wasting your time by duplicating work or by working on a task that is no longer pertinent, please search the mailing list and post your intent before embarking on a big project. ================================================== Modify chmod so that it does not change an inode's st_ctime when the selected operation would have no other effect. First suggested by Hans Ecke in https://lists.gnu.org/r/bug-coreutils/2004-09/msg00145.html Discussed more recently on . document the following in coreutils.texi: [ pinky Suggestion from Paul Eggert: More generally, there's not that much use for imaxtostr nowadays, since the inttypes module and newer versions of gettext allow things like _("truncating %s at %" PRIdMAX " bytes") to work portably. I suspect that (if someone cares to take the time) we can remove all instances of imaxtostr and umaxtostr in coreutils and gnulib. cp --recursive: use fts and *at functions to perform directory traversals in source and destination hierarchy rather than forming full file names. The latter (current) approach fails unnecessarily when the names become very long, and requires space and time that is quadratic in the depth of the hierarchy. [Bo Borgerson is working on this] printf: Now that gnulib supports *printf("%a"), import one of the *printf-posix modules so that printf(1) will support %a even on platforms where the native *printf(3) is deficient. Suggestion from Eric Blake. consider adding some implementation of the "col" utility Suggested by Karl Berry. doc/coreutils.texi: Address this comment: FIXME: mv's behavior in this case is system-dependent Better still: fix the code so it's *not* system-dependent. ls: add --format=FORMAT option that controls how each line is printed. copy.c: Address the FIXME-maybe comment in copy_internal. And once that's done, add an exclusion so that 'cp --link' no longer incurs the overhead of saving src. dev/ino and dest. filename in the hash table. Write an autoconf test to work around build failure in HPUX's 64-bit mode. See notes in README -- and remove them once there's a work-around. Integrate use of sendfile, suggested here: https://lists.gnu.org/r/bug-fileutils/2003-03/msg00030.html I don't plan to do that, since a few tests demonstrate no significant benefit. printf: consider adapting builtins/printf.def from bash tail: don't use xlseek; it *exits*. Instead, maybe use a macro and return nonzero. tr: support nontrivial equivalence classes, e.g. [=e=] with LC_COLLATE=fr_FR lib/strftime.c: Since %N is the only format that we need but that glibc's strftime doesn't support, consider using a wrapper that would expand /%(-_)?\d*N/ to the desired string and then pass the resulting string to glibc's strftime. sort: Investigate better sorting algorithms; see Knuth vol. 3. We tried list merge sort, but it was about 50% slower than the recursive algorithm currently used by sortlines, and it used more comparisons. We're not sure why this was, as the theory suggests it should do fewer comparisons, so perhaps this should be revisited. List merge sort was implemented in the style of Knuth algorithm 5.2.4L, with the optimization suggested by exercise 5.2.4-22. The test case was 140,213,394 bytes, 426,4424 lines, text taken from the GCC 3.3 distribution, sort.c compiled with GCC 2.95.4 and running on Debian 3.0r1 GNU/Linux, 2.4GHz Pentium 4, single pass with no temporary files and plenty of RAM. Since comparisons seem to be the bottleneck, perhaps the best algorithm to try next should be merge insertion. See Knuth section 5.3.1, who credits Lester Ford, Jr. and Selmer Johnson, American Mathematical Monthly 66 (1959), 387-389. shred: Update shred as described here to conform to DoD 5220 rules: https://lists.gnu.org/r/bug-coreutils/2007-05/msg00075.html Remove suspicious uses of alloca (ones that may allocate more than about 4k) Improve test coverage. See HACKING for instructions on generating an html test coverage report. Find a program that has poor coverage and improve. Changes expected to go in, someday. ====================================== dd patch from Olivier Delhomme test/mv/*: clean up $other_partition_tmpdir in all cases ls: when both -l and --dereference-command-line-symlink-to-dir are specified, consider whether to let the latter select whether to dereference command line symlinks to directories. Since -l has an implicit --NO-dereference-command-line-symlink-to-dir meaning. Pointed out by Karl Berry. Pending copyright papers: ------------------------ getpwnam from Bruce Korb pb (progress bar) from Miika Pekkarinen ------------------------------ Remove long-deprecated options. Search case-insensitive for 'deprecated' and 'remove in '. Automate this. Add a distcheck-time test to ensure that every distributed file is either read-only(indicating generated) or is version-controlled and up to date. remove all uses of the 'register' keyword: Done. add a maint.mk rule for this, too. remove or adjust chown's --changes option, since it can't always do what it currently says it does. Support arbitrary-precision arithmetic in those tools for which it makes sense. Factor and expr already support this via libgmp. The "test" program is covered via its string-based comparison of integers. To be converted: seq. Adapt tools like wc, tr, fmt, etc. (most of the textutils) to be multibyte aware. The problem is that I want to avoid duplicating significant blocks of logic, yet I also want to incur only minimal (preferably 'no') cost when operating in single-byte mode. pr's use of nstrftime can make it malloc a very large (up to SIZE_MAX) buffer ----- Copyright (C) 2002-2020 Free Software Foundation, Inc. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see .