ci

Check in a file to RCS (removes working file)

$ ci [path/to/file]

$ ci -u [path/to/file]

$ ci -l [path/to/file]

$ ci -r[2.0] [path/to/file]

$ ci -f [path/to/file]

$ ci -m"[Log message]" [path/to/file]

ci [options] file...

ci (check in) deposits the contents of a working file into an RCS (Revision Control System) archive file. RCS files store all revisions of a file, enabling version tracking and history management.
By default, ci removes the working file after check-in, leaving only the RCS archive. Use -u to keep a read-only copy or -l to keep a locked (editable) copy.
The command prompts for a log message describing the changes. This message is stored with the revision for future reference.

-l

Check in and immediately check out locked for continued editing

Check in and leave a read-only working copy

Assign specific revision number to the new revision

Force check-in even if file unchanged from previous revision

Use msg as the log message instead of prompting

Assign symbolic name to the checked-in revision

Use specified date as check-in date

Search working file for keyword values to determine revision

Requires the caller's login to be on the RCS access list (unless empty, or caller is superuser/owner). To add a revision to an existing branch, the tip must be locked by the caller.
If the revision is unchanged from the previous one, ci reverts to that revision unless -f is specified.

RCS (Revision Control System) was developed by Walter Tichy at Purdue University and first released in 1982. It was one of the earliest version control systems and influenced later systems like CVS. While largely superseded by Git and other distributed systems, RCS remains useful for simple single-file versioning.

co(1), rcs(1), rcsdiff(1), rlog(1)