rlog

Display the complete revision history of a file

$ rlog [path/to/file]

$ rlog -h [path/to/file]

$ rlog -r[revision] [path/to/file]

$ rlog -d"[start_date]<[end_date]" [path/to/file]

$ rlog -w[author] [path/to/file]

rlog [options] [file …]

-h
    Print header summary only

-l
    Local processing only; suppress locker contact

-L
    Do not print locks held by the caller

-N
    Do not print revision numbers

-n
    Do not print symbolic names

-R
    Print locks held by others

-rrev
    Print information for specific revision(s)

-sstate
    Print revisions with specified state

-t
    Print descriptive text only

-V
    Print RCS file version

-wlogin
    Print revisions checked out by login

-ddate
    Limit to revisions on or after date

The rlog command is a utility from the Revision Control System (RCS) suite used to display log messages, revision histories, and summaries for RCS files. RCS files, typically with a ,v suffix, store multiple revisions of text files along with metadata like change logs, authors, dates, and states.

Invoking rlog on an RCS file prints a comprehensive report including: a header with file description, headers, names of locks, symbolic names, and revision numbers; followed by per-revision details such as revision number, locks, date, author, state, lines added/removed, and the full log message. Without arguments, it processes all specified files comprehensively.

Options allow filtering by revision, state, or date; suppressing headers, revision numbers, or locks; and selecting descriptive text only. It's invaluable for auditing changes in legacy projects using RCS, providing insights into development history without extracting revisions. Output is human-readable and suitable for scripting or review.

Though powerful for RCS environments, rlog is rarely used today, supplanted by distributed version control systems like Git.

Operates only on RCS files (,v); ignores non-RCS files. Deprecated for modern VCS; may require RCS package installation. Date formats strict (e.g., YYYY.MM.DD).

Header: description, keywords, locks.
Per-revision: rev# date auth state lines logmsg.

rlog file.c,v — Shows full history.
rlog -h file.c,v — Header summary only.

Developed by Walter F. Tichy in 1982 as part of RCS at Purdue University. RCS 5.x versions standardized rlog; integrated into POSIX. Largely obsolete post-2000s with rise of CVS, Subversion, Git.

ci(1), co(1), rcs(1), rcsdiff(1), rcsmerge(1)