rcs —
RCS file management program
rcs |
[ -IiLqTUV
]
[-Aoldfile
]
[-ausers
]
[]
[-cstring
]
[]
[-kmode
]
[]
[-mrev:msg
]
[-orev
]
[]
[]
[-xsuffixes
]
file ... |
Revision Control System (RCS) is a software tool which lets people manage
multiple revisions of text that is revised frequently, such as source code or
documentation.
The
rcs program is used to create RCS files
or manipulate the contents of existing files. A set of helper tools is also
available: specific revisions of files may be checked in or out, using
ci(1) and
co(1); differences between revisions
viewed or merged, using
rcsdiff(1) and
rcsmerge(1); and information
about RCS files and keyword strings displayed using
rlog(1) and
ident(1). See the respective
manual pages for more information about these utilities.
The following options are supported:
-
-
-Aoldfile- Append the access list of oldfile to the
access list of the RCS files.
-
-
-ausers- Add the usernames specified in the comma-separated list
users to the access list of the RCS
files.
-
-
-b[rev
]- Set the default branch (see below) to
rev. If no argument is specified, the
default branch is set to the highest numbered branch.
-
-
-cstring- Set comment leader to string. The comment
leader specifies the comment character(s) for a file. This option is
useful for compatibility with older RCS implementations only.
-
-
-e[users
]- Remove the usernames specified in the comma-separated list
users from the access list of the RCS
files. If users is not specified, all
users are removed from the access list.
-
-
-I- Interactive mode.
-
-
-i- Create and initialize a new RCS file. If the RCS file has no path prefix,
try to first create it in the ./RCS
subdirectory or, if that fails, in the current directory. Files created
this way contain no revision.
-
-
-kmode- Specify the keyword substitution mode (see below).
-
-
-L- Enable strict locking on the RCS files.
-
-
-l[rev
]- Lock revision rev on the RCS files.
-
-
-mrev:msg- Replace revision rev's log message with
msg.
-
-
-orev- Delete one or more revisions. The specifications of the values or
revisions are as follows:
-
-
- rev
- Specific revision.
-
-
- rev1:rev2
- Delete all revisions of a branch between
rev1 and
rev2.
-
-
- rev1::rev2
- Delete all revisions of a branch between
rev1 and
rev2 without deleting revisions
rev1 and
rev2.
-
-
- :rev
- Delete all revisions of the branch until revision
rev.
-
-
- rev:
- Delete all revisions of the branch from revision
rev until the last revision of the
branch.
-
-
-q- Be quiet about reporting.
-
-
-T- Preserve the modification time of RCS files.
-
-
-t[str
]- Change the descriptive text. The argument
str is interpreted as the name of a file
containing the descriptive text or, if prefixed with a ‘-’,
the actual descriptive text itself. If no argument is used, the
descriptive text is taken from standard input terminated by end-of-file or
by a line containing the ‘.’ character by itself.
-
-
-U- Disable strict locking on the RCS files.
-
-
-u[rev
]- Unlock revision rev on the RCS
files.
-
-
-V- Print the program's version string and exit.
-
-
-xsuffixes- Specifies the suffixes for RCS files. Suffixes should be separated by the
‘/’ character.
Files may be selected by
revision or, where no
revision is specified, the latest revision of the default
branch is used. Revisions are specified either by
using the
-r option or by appending the
revision number to any option that supports it. Branches are selected using
the
-b option.
A file's revision consists of two elements: release number and level number. For
example, revision 2.3 of a file denotes release 2, level 3. Levels may also be
subdivided into sublevels: this might happen, for example, if a parallel
development is forked from a lower level revision. The primary levels and the
sublevels belong to separate branches: the primary levels belong to a branch
called HEAD, while sublevels belong to branches specified by revision.
rcs also supports the notion of
state. The state is an arbitrary string of
characters used to describe a file (or a specific revision of a file). States
can be set or changed using the
-s option,
for RCS tools which support it. The state of a file/revision can be modified
without having to check in a new file/revision. The default state is
‘Exp’ (Experimental). Examples of states could be
‘Dev’, ‘Reviewed’, or ‘Stab’.
In order to make large groups of RCS files more manageable, RCS tools have the
ability to select files by their
symbolic name.
Thus files can be selected by their symbolic name, rather than numerical
revision.
ci(1)
-N and
-n are used to set symbolic names for
files.
The following methods of file selection are therefore available: revision
number, state, and symbolic name. For options which take as argument
rev or
state, any of these methods may be used. Some
examples:
$ co -r"myproject" foo.c
$ rcs -m1.3:update foo.c
$ ci -s"Exp" bar.c
As long as source files are edited inside a working directory, their state can
be determined using the
cvs(1)
status or
log commands, but as soon as files get
exported from a local working copy, it becomes harder to identify which
revisions they are.
rcs and
cvs(1) use a mechanism known as
‘keyword substitution’ to help identify the files. Embedded
strings of the form $keyword$ and $keyword:...$ in a file are replaced with
strings of the form $keyword: value$ whenever a new revision of the file is
obtained. The possible keywords are as follows:
-
-
- $Author$
- The name of the user who checked in the revision.
-
-
- $Date$
- The date and hour (UTC) the revision was checked in.
-
-
- $Header$
- Standard header containing the full pathname of the RCS file, the revision
number, the date (UTC), the author and the state.
-
-
- $Id$ and $OpenBSD$
- The same content as $Header$ but without the path of the RCS file.
-
-
- $Log$
- The log message supplied during commit, preceded by a header containing
the RCS filename, the revision number, the author, and the date
(UTC).
-
-
- $Mdocdate$
- Produce a date of the form month name, day number, and year, suitable for
the mdoc(7) “Dd”
macro.
-
-
- $Name$
- The tag name used to check out the file.
-
-
- $RCSfile$
- The name of the RCS file, but without a path.
-
-
- $Revision$
- The revision number assigned to the revision.
-
-
- $Source$
- The full pathname of the RCS file.
-
-
- $State$
- The state assigned to the revision.
Keyword substitution has its disadvantages: sometimes the literal text string
$Author$ is wanted inside a file without
rcs or
cvs(1) interpreting it as a keyword
and expanding it. The
-ko option
can be used to turn off keyword substitution entirely though. There is
unfortunately no way to selectively turn off keyword substitution.
Each file and working directory copy of a file have a stored default
substitution mode. Substitution modes on files are set by the
-kmode
option.
The possible substitution modes are as follows:
-
-
-kb- Like
-ko,
but also avoids the conversion of line endings. This option is used to
handle binary files.
-
-
-kk- Does not substitute the keywords. Useful with the
cvs(1)
diff and
rcsdiff(1) commands to
avoid displaying the differences between keyword substitutions.
-
-
-kkv- The default behaviour. Keywords are normally substituted i.e. $Revision$
becomes $Revision: 1.1 $.
-
-
-kkvl- Like
-kkv,
except that the locker's name is displayed along with the version if the
given revision is currently locked. This option is normally not useful as
rcs and
cvs(1) do not use file locking
by default.
-
-
-ko- No substitutions are done. This option is often used with the
cvs(1)
import command to guarantee that files
that already contain external keywords do not get modified.
-
-
-kv- Substitute the value of keywords instead of keywords themselves e.g.
instead of $Revision$, only insert 1.1 and not $Revision: 1.1 $. This
option must be used with care, as it can only be used once. It is often
used with the cvs(1)
export command to freeze the values
before releasing software.
-
-
RCSINIT- If set, this variable should contain a list of space-delimited options
that are prepended to the argument list.
The
rcs utility exits 0 on success,
and >0 if an error occurs.
One of the most common uses of
rcs is to
track changes to a document containing source code.
As an example, we'll look at a user wishing to track source changes to a file
foo.c.
If the
RCS directory does not exist yet, create
it as follows and invoke the check-in command:
This command creates an RCS file
foo.c,v in the
RCS directory, stores
foo.c into it as revision 1.1, and deletes
foo.c.
ci(1) will prompt for a description
of the file to be entered. Whenever a newly created (or updated) file is
checked-in,
ci(1) will prompt for a
log message to be entered which should summarize the changes made to the file.
That log message will be added to the RCS file along with the new revision.
The
co(1) command can now be used to
obtain a copy of the checked-in
foo.c,v file:
$ co foo.c
This command checks the file out in unlocked mode. If a user wants to have
exclusive access to the file to make changes to it, it needs to be checked out
in locked mode using the
-l option of the
co(1) command. Only one concurrent
locked checkout of a revision is permitted.
Once changes have been made to the
foo.c
file, and before checking the file in, the
rcsdiff(1) command can be used
to view changes between the working file and the most recently checked-in
revision:
$ rcsdiff -u foo.c
The
-u option produces a unified diff. See
diff(1) for more information.
ci(1),
co(1),
cvs(1),
ident(1),
rcsclean(1),
rcsdiff(1),
rcsmerge(1),
rlog(1)
Tichy, Walter F.,
RCS — a system for version control,
Software — Practice & Experience,
15:7, pp. 637-654,
July, 1985.
OpenRCS is compatible with Walter Tichy's original RCS implementation.
The flags [
-Mz
] have no
effect and are provided for compatibility only.
The OpenRCS project is a BSD-licensed rewrite of the original Revision Control
System and first appeared in
OpenBSD 4.0.
OpenRCS was written by
Jean-Francois
Brousseau,
Joris Vink,
Niall O'Higgins, and
Xavier Santolaria.
The original RCS code was written in large parts by
Walter F. Tichy and
Paul Eggert.
For historical reasons, the RCS tools do not permit whitespace between options
and their arguments.
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