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3.3 Still missing

RCS is still missing some features. The following is an unordered list of “to-do musings” kept by the RCS maintainers. If you would like to hack on an item, See Reporting bugs.

• Add an option to rcsmerge so that it can use an arbitrary program to do the 3-way merge, instead of the default merge. Likewise for rcsdiff and diff. It should be possible to pass arbitrary options to these programs, and to the subsidiary co invocations.
• Add format options for finer control over the output of ident and rlog. E.g. there should be an easy way for rlog to output lines like ‘src/main.c 2.4 wft’, one for each locked revision. rlog options should have three orthogonal types: selecting files, selecting revisions, and selecting rlog format.
• Add format options for finer control over the output of keyword strings. E.g. there should be some way to prepend ‘@(#)’, and there should be some way to change ‘$’ to some other character to disable further substitution. These options should make the resulting files uneditable, like ‘-kv’.
• Add long options, e.g. --keyword-substitution. Unfortunately RCS’s option syntax is incompatible with getopt. Perhaps the best way is to overload rcs, e.g., ‘rcs diff --keyword-substitution=old file’ instead of ‘rcsdiff -ko file’.
• rlog -rM:N should work even if M and N have different numbers of fields, so long as M is an ancestor of N or vice versa.
• rcs should evaluate options in order; this allows rcs -oS -nS.
• Be able to redo your most recent checkin with minor changes.
• co -u shouldn’t complain about a ‘+w’ working file if contents don’t change.
• Add a ‘-’ option to take the list of file names from standard input. Perhaps the file names should be null-terminated, not newline-terminated, so that those that contain newlines are handled properly.
• Permit multiple option–filename pairs, e.g., co -r1.4 a -r1.5 b.
• Add an option to break a symbolic link to an RCS file, instead of breaking the hard link that it points to.
• Add ways to specify the earliest revision, the most recent revision, the earliest or latest revision on a particular branch, and the parent or child of some other revision.
• If a user has multiple locks, perhaps ci should fall back on the method of ci -k to figure out which revision to use.
• Add an option to rcsclean to clean directories recursively.
• Write an rcsck program that repairs corrupted RCS files, much as fsck repairs corrupted file systems. For example, it should remove stale lock files.
• Update the date parser to use the more modern getdate.y by Bellovin, Salz, and Berets, or the even more modern getdate by Moraes. None of these getdate implementations are as robust as RCS’s old warhorse in avoiding problems like arithmetic overflow, so they’ll have to be fixed first. (Perhaps we can use gnulib module getdate.)
• Break up the code into a library so that it’s easier to write new programs that manipulate RCS files, and so that useless code is removed from the existing programs. For example, the rcs command contains unnecessary keyword substitution baggage, and the merge command can be greatly pruned.
• Make it easier to use your favorite text editor to edit log messages, etc., instead of having to type them in irretrievably at the terminal.
• Let the user specify a search path for default branches, e.g., to use L as the default branch if it works, and M otherwise. Let the user require that at least one entry in the search path works. Let the user say that later entries in the search path are read only, i.e. one cannot check in changes to them. This should be an option settable by ‘RCSINIT’.
• Add a way for a user to see which revisions affected which lines.
• Have rlog -nN F print just the revision number that N translates to. E.g., rlog -nB. F would print the highest revision on the branch B. Use this to add an option -bB to rcsbranch, to freeze the named branch. This should interact well with default branches.
• Add a co option that prints the revision number before each line, as SCCS’s get -m does. [I implemented this for Emacs 22 as a subroutine of vc-annotate, q.v. —ttn]