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Reference manual for CVS commands

This appendix describes how to invoke CVS, and describes in detail those subcommands of CVS which are not fully described elsewhere. To look up a particular subcommand, see section Index.

Overall structure of CVS commands

The overall format of all CVS commands is:

cvs [ cvs_options ] cvs_command [ command_options ] [ command_args ]
cvs
The name of the CVS program.
cvs_options
Some options that affect all sub-commands of CVS. These are described below.
cvs_command
One of several different sub-commands. Some of the commands have aliases that can be used instead; those aliases are noted in the reference manual for that command. There are only two situations where you may omit `cvs_command': `cvs -H' elicits a list of available commands, and `cvs -v' displays version information on CVS itself.
command_options
Options that are specific for the command.
command_args
Arguments to the commands.

There is unfortunately some confusion between cvs_options and command_options. `-l', when given as a cvs_option, only affects some of the commands. When it is given as a command_option is has a different meaning, and is accepted by more commands. In other words, do not take the above categorization too seriously. Look at the documentation instead.

Default options and the ~/.cvsrc file

There are some command_options that are used so often that you might have set up an alias or some other means to make sure you always specify that option. One example (the one that drove the implementation of the .cvsrc support, actually) is that many people find the default output of the `diff' command to be very hard to read, and that either context diffs or unidiffs are much easier to understand.

The `~/.cvsrc' file is a way that you can add default options to cvs_commands within cvs, instead of relying on aliases or other shell scripts.

The format of the `~/.cvsrc' file is simple. The file is searched for a line that begins with the same name as the cvs_command being executed. If a match is found, then the remainder of the line is split up (at whitespace characters) into separate options and added to the command arguments before any options from the command line.

If a command has two names (e.g., checkout and co), the official name, not necessarily the one used on the command line, will be used to match against the file. So if this is the contents of the user's `~/.cvsrc' file:

log -N
diff -u
update -P
co -P

the command `cvs checkout foo' would have the `-P' option added to the arguments, as well as `cvs co foo'.

With the example file above, the output from `cvs diff foobar' will be in unidiff format. `cvs diff -c foobar' will provide context diffs, as usual. Getting "old" format diffs would be slightly more complicated, because diff doesn't have an option to specify use of the "old" format, so you would need `cvs -f diff foobar'.

In place of the command name you can use cvs to specify global options (see section Global options). For example the following line in `.cvsrc'

cvs -z6

causes CVS to use compression level 6

Global options

The available `cvs_options' (that are given to the left of `cvs_command') are:

-b bindir
Use bindir as the directory where RCS programs are located. Overrides the setting of the $RCSBIN environment variable and any precompiled directory. This parameter should be specified as an absolute pathname.
-T tempdir
Use tempdir as the directory where temporary files are located. Overrides the setting of the $TMPDIR environment variable and any precompiled directory. This parameter should be specified as an absolute pathname.
-d cvs_root_directory
Use cvs_root_directory as the root directory pathname of the repository. Overrides the setting of the $CVSROOT environment variable. See section The Repository.
-e editor
Use editor to enter revision log information. Overrides the setting of the $CVSEDITOR and $EDITOR environment variables.
-f
Do not read the `~/.cvsrc' file. This option is most often used because of the non-orthogonality of the CVS option set. For example, the `cvs log' option `-N' (turn off display of tag names) does not have a corresponding option to turn the display on. So if you have `-N' in the `~/.cvsrc' entry for `log', you may need to use `-f' to show the tag names.
-H
Display usage information about the specified `cvs_command' (but do not actually execute the command). If you don't specify a command name, `cvs -H' displays a summary of all the commands available.
-l
Do not log the cvs_command in the command history (but execute it anyway). See section history--Show status of files and users, for information on command history.
-n
Do not change any files. Attempt to execute the `cvs_command', but only to issue reports; do not remove, update, or merge any existing files, or create any new files.
-Q
Cause the command to be really quiet; the command will only generate output for serious problems.
-q
Cause the command to be somewhat quiet; informational messages, such as reports of recursion through subdirectories, are suppressed.
-r
Make new working files files read-only. Same effect as if the $CVSREAD environment variable is set (see section All environment variables which affect CVS). The default is to make working files writable, unless watches are on (see section Mechanisms to track who is editing files).
-s variable=value
Set a user variable (see section Expansions in administrative files).
-t
Trace program execution; display messages showing the steps of CVS activity. Particularly useful with `-n' to explore the potential impact of an unfamiliar command.
-v
Display version and copyright information for CVS.
-w
Make new working files read-write. Overrides the setting of the $CVSREAD environment variable. Files are created read-write by default, unless $CVSREAD is set or `-r' is given.
-x
Encrypt all communication between the client and the server. Only has an effect on the CVS client. As of this writing, this is only implemented when using a Kerberos connection (see section Direct connection with kerberos). Encryption support is not available by default; it must be enabled using a special configure option, `--enable-encryption', when you build CVS.
-z gzip-level
Set the compression level. Only has an effect on the CVS client.

Common command options

This section describes the `command_options' that are available across several CVS commands. These options are always given to the right of `cvs_command'. Not all commands support all of these options; each option is only supported for commands where it makes sense. However, when a command has one of these options you can almost always count on the same behavior of the option as in other commands. (Other command options, which are listed with the individual commands, may have different behavior from one CVS command to the other).

Warning: the `history' command is an exception; it supports many options that conflict even with these standard options.

-D date_spec
Use the most recent revision no later than date_spec. date_spec is a single argument, a date description specifying a date in the past. The specification is sticky when you use it to make a private copy of a source file; that is, when you get a working file using `-D', CVS records the date you specified, so that further updates in the same directory will use the same date (for more information on sticky tags/dates, see section Sticky tags). A wide variety of date formats are supported by CVS. The date_spec is interpreted as being in the local timezone, unless a specific timezone is specified. Examples of valid date specifications include:
                    1 month ago
                    2 hours ago
                    400000 seconds ago
                    last year
                    last Monday
                    yesterday
                    a fortnight ago
                    3/31/92 10:00:07 PST
                    January 23, 1987 10:05pm
                    22:00 GMT
`-D' is available with the checkout, diff, export, history, rdiff, rtag, and update commands. (The history command uses this option in a slightly different way; see section history options). Note that when specifying a date like `3/31/92' it is month/day/year. So `1/4/96' is January 4, not March 1. Remember to quote the argument to the `-D' flag so that your shell doesn't interpret spaces as argument separators. A command using the `-D' flag can look like this:
$ cvs diff -D "1 hour ago" cvs.texinfo
-f
When you specify a particular date or tag to CVS commands, they normally ignore files that do not contain the tag (or did not exist prior to the date) that you specified. Use the `-f' option if you want files retrieved even when there is no match for the tag or date. (The most recent revision of the file will be used). `-f' is available with these commands: checkout, export, rdiff, rtag, and update. Warning: The commit command also has a `-f' option, but it has a different behavior for that command. See section commit options.
-H
Help; describe the options available for this command. This is the only option supported for all CVS commands.
-k kflag
Alter the default RCS processing of keywords. See section Keyword substitution, for the meaning of kflag. Your kflag specification is sticky when you use it to create a private copy of a source file; that is, when you use this option with the checkout or update commands, CVS associates your selected kflag with the file, and continues to use it with future update commands on the same file until you specify otherwise. The `-k' option is available with the add, checkout, diff and update commands.
-l
Local; run only in current working directory, rather than recursing through subdirectories. Warning: this is not the same as the overall `cvs -l' option, which you can specify to the left of a cvs command! Available with the following commands: checkout, commit, diff, export, log, remove, rdiff, rtag, status, tag, and update.
-m message
Use message as log information, instead of invoking an editor. Available with the following commands: add, commit and import.
-n
Do not run any checkout/commit/tag program. (A program can be specified to run on each of these activities, in the modules database (see section The modules file); this option bypasses it). Warning: this is not the same as the overall `cvs -n' option, which you can specify to the left of a cvs command! Available with the checkout, commit, export, and rtag commands.
-P
Prune (remove) directories that are empty after being updated, on checkout, or update. Normally, an empty directory (one that is void of revision-controlled files) is left alone. Specifying `-P' will cause these directories to be silently removed from your checked-out sources. This does not remove the directory from the repository, only from your checked out copy. Note that this option is implied by the `-r' or `-D' options of checkout and export.
-p
Pipe the files retrieved from the repository to standard output, rather than writing them in the current directory. Available with the checkout and update commands.
-W
Specify file names that should be filtered. You can use this option repeatedly. The spec can be a file name pattern of the same type that you can specify in the `.cvswrappers' file. Avaliable with the following commands: import, and update.
-r tag
Use the revision specified by the tag argument instead of the default head revision. As well as arbitrary tags defined with the tag or rtag command, two special tags are always available: `HEAD' refers to the most recent version available in the repository, and `BASE' refers to the revision you last checked out into the current working directory. The tag specification is sticky when you use this with checkout or update to make your own copy of a file: CVS remembers the tag and continues to use it on future update commands, until you specify otherwise (for more information on sticky tags/dates, see section Sticky tags). The tag can be either a symbolic or numeric tag. See section Tags--Symbolic revisions. Specifying the `-q' global option along with the `-r' command option is often useful, to suppress the warning messages when the RCS history file does not contain the specified tag. Warning: this is not the same as the overall `cvs -r' option, which you can specify to the left of a cvs command! `-r' is available with the checkout, commit, diff, history, export, rdiff, rtag, and update commands.

admin--Administration front end for rcs

This is the CVS interface to assorted administrative RCS facilities, documented in rcs(1). admin simply passes all its options and arguments to the rcs command; it does no filtering or other processing. This command does work recursively, however, so extreme care should be used.

If there is a group whose name matches a compiled in value which defaults to cvsadmin, only members of that group can use cvs admin. To disallow cvs admin for all users, create a group with no users in it.

admin options

Not all valid rcs options are useful together with CVS. Some even makes it impossible to use CVS until you undo the effect!

This description of the available options is based on the `rcs(1)' man page, but modified to suit readers that are more interrested in CVS than RCS.

-Aoldfile
Might not work together with CVS. Append the access list of oldfile to the access list of the RCS file.
-alogins
Might not work together with CVS. Append the login names appearing in the comma-separated list logins to the access list of the RCS file.
-b[rev]
When used with bare RCS, this option sets the default branch to rev; in CVS sticky tags (see section Sticky tags) are a better way to decide which branch you want to work on. With CVS, this option can be used to control behavior with respect to the vendor branch.
-cstring
Useful with CVS. Sets the comment leader to string. The comment leader is printed before every log message line generated by the keyword $Log$ (see section Keyword substitution). This is useful for programming languages without multi-line comments. RCS initially guesses the value of the comment leader from the file name extension when the file is first committed.
-e[logins]
Might not work together with CVS. Erase the login names appearing in the comma-separated list logins from the access list of the RCS file. If logins is omitted, erase the entire access list.
-I
Run interactively, even if the standard input is not a terminal.
-i
Useless with CVS. When using bare RCS, this is used to create and initialize a new RCS file, without depositing a revision.
-ksubst
Useful with CVS. Set the default keyword substitution to subst. See section Keyword substitution. Giving an explicit `-k' option to cvs update, cvs export, or cvs checkout overrides this default.
-l[rev]
Lock the revision with number rev. If a branch is given, lock the latest revision on that branch. If rev is omitted, lock the latest revision on the default branch. This can be used in conjunction with the `rcslock.pl' script in the `contrib' directory of the CVS source distribution to provide reserved checkouts (where only one user can be editing a given file at a time). See the comments in that file for details (and see the `README' file in that directory for disclaimers about the unsupported nature of contrib). According to comments in that file, locking must set to strict (which is the default).
-L
Set locking to strict. Strict locking means that the owner of an RCS file is not exempt from locking for checkin. For use with CVS, strict locking must be set; see the discussion under the `-l' option above.
-mrev:msg
Replace the log message of revision rev with msg.
-Nname[:[rev]]
Act like `-n', except override any previous assignment of name.
-nname[:[rev]]
Associate the symbolic name name with the branch or revision rev. It is normally better to use `cvs tag' or `cvs rtag' instead. Delete the symbolic name if both `:' and rev are omitted; otherwise, print an error message if name is already associated with another number. If rev is symbolic, it is expanded before association. A rev consisting of a branch number followed by a `.' stands for the current latest revision in the branch. A `:' with an empty rev stands for the current latest revision on the default branch, normally the trunk. For example, `rcs -nname: RCS/*' associates name with the current latest revision of all the named RCS files; this contrasts with `rcs -nname:$ RCS/*' which associates name with the revision numbers extracted from keyword strings in the corresponding working files.
-orange
Potentially useful, but dangerous, with CVS (see below). Deletes (outdates) the revisions given by range. A range consisting of a single revision number means that revision. A range consisting of a branch number means the latest revision on that branch. A range of the form `rev1:rev2' means revisions rev1 to rev2 on the same branch, `:rev' means from the beginning of the branch containing rev up to and including rev, and `rev:' means from revision rev to the end of the branch containing rev. None of the outdated revisions may have branches or locks. Due to the way CVS handles branches rev cannot be specified symbolically if it is a branch. See section Magic branch numbers, for an explanation. Make sure that no-one has checked out a copy of the revision you outdate. Strange things will happen if he starts to edit it and tries to check it back in. For this reason, this option is not a good way to take back a bogus commit; commit a new revision undoing the bogus change instead (see section Merging differences between any two revisions).
-q
Run quietly; do not print diagnostics.
-sstate[:rev]
Useful with CVS. Set the state attribute of the revision rev to state. If rev is a branch number, assume the latest revision on that branch. If rev is omitted, assume the latest revision on the default branch. Any identifier is acceptable for state. A useful set of states is `Exp' (for experimental), `Stab' (for stable), and `Rel' (for released). By default, the state of a new revision is set to `Exp' when it is created. The state is visible in the output from cvs log (see section log--Print out log information for files), and in the `$'Log$ and `$'State$ keywords (see section Keyword substitution). Note that CVS uses the dead state for its own purposes; to take a file to or from the dead state use commands like cvs remove and cvs add, not cvs admin -s.
-t[file]
Useful with CVS. Write descriptive text from the contents of the named file into the RCS file, deleting the existing text. The file pathname may not begin with `-'. If file is omitted, obtain the text from standard input, terminated by end-of-file or by a line containing `.' by itself. Prompt for the text if interaction is possible; see `-I'. The descriptive text can be seen in the output from `cvs log' (see section log--Print out log information for files).
-t-string
Similar to `-tfile'. Write descriptive text from the string into the RCS file, deleting the existing text.
-U
Set locking to non-strict. Non-strict locking means that the owner of a file need not lock a revision for checkin. For use with CVS, strict locking must be set; see the discussion under the `-l' option above.
-u[rev]
See the option `-l' above, for a discussion of using this option with CVS. Unlock the revision with number rev. If a branch is given, unlock the latest revision on that branch. If rev is omitted, remove the latest lock held by the caller. Normally, only the locker of a revision may unlock it. Somebody else unlocking a revision breaks the lock. This causes a mail message to be sent to the original locker. The message contains a commentary solicited from the breaker. The commentary is terminated by end-of-file or by a line containing . by itself.
-Vn
Emulate RCS version n. Use -Vn to make an RCS file acceptable to RCS version n by discarding information that would confuse version n.
-xsuffixes
Useless with CVS. Use suffixes to characterize RCS files.

admin examples

Outdating is dangerous

First, an example of how not to use the admin command. It is included to stress the fact that this command can be quite dangerous unless you know exactly what you are doing.

The `-o' option can be used to outdate old revisions from the history file. If you are short on disc this option might help you. But think twice before using it--there is no way short of restoring the latest backup to undo this command!

The next line is an example of a command that you would not like to execute.

$ cvs admin -o:R_1_02 .

The above command will delete all revisions up to, and including, the revision that corresponds to the tag R_1_02. But beware! If there are files that have not changed between R_1_02 and R_1_03 the file will have the same numerical revision number assigned to the tags R_1_02 and R_1_03. So not only will it be impossible to retrieve R_1_02; R_1_03 will also have to be restored from the tapes!

Comment leaders

If you use the $Log$ keyword and you do not agree with the guess for comment leader that CVS has done, you can enforce your will with cvs admin -c. This might be suitable for nroff source:

$ cvs admin -c'.\" ' *.man
$ rm *.man
$ cvs update

The two last steps are to make sure that you get the versions with correct comment leaders in your working files.

checkout--Check out sources for editing

Make a working directory containing copies of the source files specified by modules. You must execute checkout before using most of the other CVS commands, since most of them operate on your working directory.

The modules part of the command are either symbolic names for some collection of source directories and files, or paths to directories or files in the repository. The symbolic names are defined in the `modules' file. See section The modules file.

Depending on the modules you specify, checkout may recursively create directories and populate them with the appropriate source files. You can then edit these source files at any time (regardless of whether other software developers are editing their own copies of the sources); update them to include new changes applied by others to the source repository; or commit your work as a permanent change to the source repository.

Note that checkout is used to create directories. The top-level directory created is always added to the directory where checkout is invoked, and usually has the same name as the specified module. In the case of a module alias, the created sub-directory may have a different name, but you can be sure that it will be a sub-directory, and that checkout will show the relative path leading to each file as it is extracted into your private work area (unless you specify the `-Q' global option).

The files created by checkout are created read-write, unless the `-r' option to CVS (see section Global options) is specified, the CVSREAD environment variable is specified (see section All environment variables which affect CVS), or a watch is in effect for that file (see section Mechanisms to track who is editing files).

Running checkout on a directory that was already built by a prior checkout is also permitted, and has the same effect as specifying the `-d' option to the update command, that is, any new directories that have been created in the repository will appear in your work area. See section update--Bring work tree in sync with repository.

For the output produced by the checkout command see section update output.

checkout options

These standard options are supported by checkout (see section Common command options, for a complete description of them):

-D date
Use the most recent revision no later than date. This option is sticky, and implies `-P'. See section Sticky tags, for more information on sticky tags/dates.
-f
Only useful with the `-D date' or `-r tag' flags. If no matching revision is found, retrieve the most recent revision (instead of ignoring the file).
-k kflag
Process RCS keywords according to kflag. See co(1). This option is sticky; future updates of this file in this working directory will use the same kflag. The status command can be viewed to see the sticky options. See section status--Display status information on checked out files.
-l
Local; run only in current working directory.
-n
Do not run any checkout program (as specified with the `-o' option in the modules file; see section The modules file).
-P
Prune empty directories.
-p
Pipe files to the standard output.
-r tag
Use revision tag. This option is sticky, and implies `-P'. See section Sticky tags, for more information on sticky tags/dates.

In addition to those, you can use these special command options with checkout:

-A
Reset any sticky tags, dates, or `-k' options. See section Sticky tags, for more information on sticky tags/dates.
-c
Copy the module file, sorted, to the standard output, instead of creating or modifying any files or directories in your working directory.
-d dir
Create a directory called dir for the working files, instead of using the module name. Unless you also use `-N', the paths created under dir will be as short as possible.
-j tag
With two `-j' options, merge changes from the revision specified with the first `-j' option to the revision specified with the second `j' option, into the working directory. With one `-j' option, merge changes from the ancestor revision to the revision specified with the `-j' option, into the working directory. The ancestor revision is the common ancestor of the revision which the working directory is based on, and the revision specified in the `-j' option. In addition, each -j option can contain an optional date specification which, when used with branches, can limit the chosen revision to one within a specific date. An optional date is specified by adding a colon (:) to the tag: `-jSymbolic_Tag:Date_Specifier'. See section Merging.
-N
Only useful together with `-d dir'. With this option, CVS will not shorten module paths in your working directory. (Normally, CVS shortens paths as much as possible when you specify an explicit target directory).
-s
Like `-c', but include the status of all modules, and sort it by the status string. See section The modules file, for info about the `-s' option that is used inside the modules file to set the module status.

checkout examples

Get a copy of the module `tc':

$ cvs checkout tc

Get a copy of the module `tc' as it looked one day ago:

$ cvs checkout -D yesterday tc

commit--Check files into the repository

Warning: The `-f file' option will probably be renamed to `-F file', and `-f' will be given a new behavior in future releases of CVS.

Use commit when you want to incorporate changes from your working source files into the source repository.

If you don't specify particular files to commit, all of the files in your working current directory are examined. commit is careful to change in the repository only those files that you have really changed. By default (or if you explicitly specify the `-R' option), files in subdirectories are also examined and committed if they have changed; you can use the `-l' option to limit commit to the current directory only.

commit verifies that the selected files are up to date with the current revisions in the source repository; it will notify you, and exit without committing, if any of the specified files must be made current first with update (see section update--Bring work tree in sync with repository). commit does not call the update command for you, but rather leaves that for you to do when the time is right.

When all is well, an editor is invoked to allow you to enter a log message that will be written to one or more logging programs (see section The modules file, and see section Loginfo) and placed in the RCS history file inside the repository. This log message can be retrieved with the log command; See section log--Print out log information for files. You can specify the log message on the command line with the `-m message' option, and thus avoid the editor invocation, or use the `-f file' option to specify that the argument file contains the log message.

commit options

These standard options are supported by commit (see section Common command options, for a complete description of them):

-l
Local; run only in current working directory.
-n
Do not run any module program.
-R
Commit directories recursively. This is on by default.
-r revision
Commit to revision. revision must be either a branch, or a revision on the main trunk that is higher than any existing revision number. You cannot commit to a specific revision on a branch.

commit also supports these options:

-F file
This option is present in CVS releases 1.3-s3 and later. Read the log message from file, instead of invoking an editor.
-f
This option is present in CVS 1.3-s3 and later releases of CVS. Note that this is not the standard behavior of the `-f' option as defined in See section Common command options. Force CVS to commit a new revision even if you haven't made any changes to the file. If the current revision of file is 1.7, then the following two commands are equivalent:
$ cvs commit -f file
$ cvs commit -r 1.8 file
-f file
This option is present in CVS releases 1.3, 1.3-s1 and 1.3-s2. Note that this is not the standard behavior of the `-f' option as defined in See section Common command options. Read the log message from file, instead of invoking an editor.
-m message
Use message as the log message, instead of invoking an editor.

commit examples

New major release number

When you make a major release of your product, you might want the revision numbers to track your major release number. You should normally not care about the revision numbers, but this is a thing that many people want to do, and it can be done without doing any harm.

To bring all your files up to the RCS revision 3.0 (including those that haven't changed), you might do:

$ cvs commit -r 3.0

Note that it is generally a bad idea to try to make the RCS revision number equal to the current release number of your product. You should think of the revision number as an internal number that the CVS package maintains, and that you generally never need to care much about. Using the tag and rtag commands you can give symbolic names to the releases instead. See section tag--Add a symbolic tag to checked out versions of files and See section rtag--Add a symbolic tag to a module.

Note that the number you specify with `-r' must be larger than any existing revision number. That is, if revision 3.0 exists, you cannot `cvs commit -r 1.3'.

Committing to a branch

You can commit to a branch revision (one that has an even number of dots) with the `-r' option. To create a branch revision, use the `-b' option of the rtag or tag commands (see section tag--Add a symbolic tag to checked out versions of files or see section rtag--Add a symbolic tag to a module). Then, either checkout or update can be used to base your sources on the newly created branch. From that point on, all commit changes made within these working sources will be automatically added to a branch revision, thereby not disturbing main-line development in any way. For example, if you had to create a patch to the 1.2 version of the product, even though the 2.0 version is already under development, you might do:

$ cvs rtag -b -r FCS1_2 FCS1_2_Patch product_module
$ cvs checkout -r FCS1_2_Patch product_module
$ cd product_module
[[ hack away ]]
$ cvs commit

This works automatically since the `-r' option is sticky.

Creating the branch after editing

Say you have been working on some extremely experimental software, based on whatever revision you happened to checkout last week. If others in your group would like to work on this software with you, but without disturbing main-line development, you could commit your change to a new branch. Others can then checkout your experimental stuff and utilize the full benefit of CVS conflict resolution. The scenario might look like:

[[ hacked sources are present ]]
$ cvs tag -b EXPR1
$ cvs update -r EXPR1
$ cvs commit

The update command will make the `-r EXPR1' option sticky on all files. Note that your changes to the files will never be removed by the update command. The commit will automatically commit to the correct branch, because the `-r' is sticky. You could also do like this:

[[ hacked sources are present ]]
$ cvs tag -b EXPR1
$ cvs commit -r EXPR1

but then, only those files that were changed by you will have the `-r EXPR1' sticky flag. If you hack away, and commit without specifying the `-r EXPR1' flag, some files may accidentally end up on the main trunk.

To work with you on the experimental change, others would simply do

$ cvs checkout -r EXPR1 whatever_module

diff--Run diffs between revisions

The diff command is used to compare different revisions of files. The default action is to compare your working files with the revisions they were based on, and report any differences that are found.

If any file names are given, only those files are compared. If any directories are given, all files under them will be compared.

The exit status will be 0 if no differences were found, 1 if some differences were found, and 2 if any error occurred.

diff options

These standard options are supported by diff (see section Common command options, for a complete description of them):

-D date
Use the most recent revision no later than date. See `-r' for how this affects the comparison. CVS can be configured to pass the `-D' option through to rcsdiff (which in turn passes it on to diff. GNU diff uses `-D' as a way to put cpp-style `#define' statements around the output differences. There is no way short of testing to figure out how CVS was configured. In the default configuration CVS will use the `-D date' option.
-k kflag
Process RCS keywords according to kflag. See co(1).
-l
Local; run only in current working directory.
-R
Examine directories recursively. This option is on by default.
-r tag
Compare with revision tag. Zero, one or two `-r' options can be present. With no `-r' option, the working file will be compared with the revision it was based on. With one `-r', that revision will be compared to your current working file. With two `-r' options those two revisions will be compared (and your working file will not affect the outcome in any way). One or both `-r' options can be replaced by a `-D date' option, described above.

Any other options that are found are passed through to rcsdiff, which in turn passes them to diff. The exact meaning of the options depends on which diff you are using. The long options introduced in GNU diff 2.0 are not yet supported in CVS. See the documentation for your diff to see which options are supported.

diff examples

The following line produces a Unidiff (`-u' flag) between revision 1.14 and 1.19 of `backend.c'. Due to the `-kk' flag no keywords are substituted, so differences that only depend on keyword substitution are ignored.

$ cvs diff -kk -u -r 1.14 -r 1.19 backend.c

Suppose the experimental branch EXPR1 was based on a set of files tagged RELEASE_1_0. To see what has happened on that branch, the following can be used:

$ cvs diff -r RELEASE_1_0 -r EXPR1

A command like this can be used to produce a context diff between two releases:

$ cvs diff -c -r RELEASE_1_0 -r RELEASE_1_1 > diffs

If you are maintaining ChangeLogs, a command like the following just before you commit your changes may help you write the ChangeLog entry. All local modifications that have not yet been committed will be printed.

$ cvs diff -u | less

export--Export sources from CVS, similar to checkout

This command is a variant of checkout; use it when you want a copy of the source for module without the CVS administrative directories. For example, you might use export to prepare source for shipment off-site. This command requires that you specify a date or tag (with `-D' or `-r'), so that you can count on reproducing the source you ship to others.

One often would like to use `-kv' with cvs export. This causes any RCS keywords to be expanded such that an import done at some other site will not lose the keyword revision information. But be aware that doesn't handle an export containing binary files correctly. Also be aware that after having used `-kv', one can no longer use the ident command (which is part of the RCS suite--see ident(1)) which looks for RCS keyword strings. If you want to be able to use ident you must not use `-kv'.

export options

These standard options are supported by export (see section Common command options, for a complete description of them):

-D date
Use the most recent revision no later than date.
-f
If no matching revision is found, retrieve the most recent revision (instead of ignoring the file).
-l
Local; run only in current working directory.
-n
Do not run any checkout program.
-R
Export directories recursively. This is on by default.
-r tag
Use revision tag.

In addition, these options (that are common to checkout and export) are also supported:

-d dir
Create a directory called dir for the working files, instead of using the module name. Unless you also use `-N', the paths created under dir will be as short as possible.
-k subst
Set keyword expansion mode (see section Substitution modes).
-N
Only useful together with `-d dir'. With this option, CVS will not shorten module paths in your working directory. (Normally, CVS shortens paths as much as possible when you specify an explicit target directory.)

history--Show status of files and users

CVS can keep a history file that tracks each use of the checkout, commit, rtag, update, and release commands. You can use history to display this information in various formats.

Logging must be enabled by creating the file `$CVSROOT/CVSROOT/history'.

Warning: history uses `-f', `-l', `-n', and `-p' in ways that conflict with the normal use inside CVS (see section Common command options).

history options

Several options (shown above as `-report') control what kind of report is generated:

-c
Report on each time commit was used (i.e., each time the repository was modified).
-e
Everything (all record types); equivalent to specifying `-xMACFROGWUT'.
-m module
Report on a particular module. (You can meaningfully use `-m' more than once on the command line.)
-o
Report on checked-out modules.
-T
Report on all tags.
-x type
Extract a particular set of record types type from the CVS history. The types are indicated by single letters, which you may specify in combination. Certain commands have a single record type:
F
release
O
checkout
T
rtag
One of four record types may result from an update:
C
A merge was necessary but collisions were detected (requiring manual merging).
G
A merge was necessary and it succeeded.
U
A working file was copied from the repository.
W
The working copy of a file was deleted during update (because it was gone from the repository).
One of three record types results from commit:
A
A file was added for the first time.
M
A file was modified.
R
A file was removed.

The options shown as `-flags' constrain or expand the report without requiring option arguments:

-a
Show data for all users (the default is to show data only for the user executing history).
-l
Show last modification only.
-w
Show only the records for modifications done from the same working directory where history is executing.

The options shown as `-options args' constrain the report based on an argument:

-b str
Show data back to a record containing the string str in either the module name, the file name, or the repository path.
-D date
Show data since date. This is slightly different from the normal use of `-D date', which selects the newest revision older than date.
-p repository
Show data for a particular source repository (you can specify several `-p' options on the same command line).
-r rev
Show records referring to revisions since the revision or tag named rev appears in individual RCS files. Each RCS file is searched for the revision or tag.
-t tag
Show records since tag tag was last added to the the history file. This differs from the `-r' flag above in that it reads only the history file, not the RCS files, and is much faster.
-u name
Show records for user name.

import--Import sources into CVS, using vendor branches

Use import to incorporate an entire source distribution from an outside source (e.g., a source vendor) into your source repository directory. You can use this command both for initial creation of a repository, and for wholesale updates to the module from the outside source. See section Tracking third-party sources, for a discussion on this subject.

The repository argument gives a directory name (or a path to a directory) under the CVS root directory for repositories; if the directory did not exist, import creates it.

When you use import for updates to source that has been modified in your source repository (since a prior import), it will notify you of any files that conflict in the two branches of development; use `checkout -j' to reconcile the differences, as import instructs you to do.

If CVS decides a file should be ignored (see section Ignoring files via cvsignore), it does not import it and prints `I ' followed by the filename (see section import output, for a complete description of the output).

If the file `$CVSROOT/CVSROOT/cvswrappers' exists, any file whose names match the specifications in that file will be treated as packages and the appropriate filtering will be performed on the file/directory before being imported, See section The cvswrappers file.

The outside source is saved in a first-level RCS branch, by default 1.1.1. Updates are leaves of this branch; for example, files from the first imported collection of source will be revision 1.1.1.1, then files from the first imported update will be revision 1.1.1.2, and so on.

At least three arguments are required. repository is needed to identify the collection of source. vendortag is a tag for the entire branch (e.g., for 1.1.1). You must also specify at least one releasetag to identify the files at the leaves created each time you execute import.

import options

This standard option is supported by import (see section Common command options, for a complete description):

-m message
Use message as log information, instead of invoking an editor.

There are three additional special options.

-b branch
Specify a first-level branch other than 1.1.1. Unless the `-b branch' flag is given, revisions will always be made to the branch 1.1.1--even if a vendortag that matches another branch is given! What happens in that case, is that the tag will be reset to 1.1.1. Warning: This behavior might change in the future.
-k subst
Indicate the RCS keyword expansion mode desired. This setting will apply to all files created during the import, but not to any files that previously existed in the repository. See section Substitution modes for a list of valid `-k' settings.
-I name
Specify file names that should be ignored during import. You can use this option repeatedly. To avoid ignoring any files at all (even those ignored by default), specify `-I !'. name can be a file name pattern of the same type that you can specify in the `.cvsignore' file. See section Ignoring files via cvsignore.
-W spec
Specify file names that should be filtered during import. You can use this option repeatedly. spec can be a file name pattern of the same type that you can specify in the `.cvswrappers' file. See section The cvswrappers file.

import output

import keeps you informed of its progress by printing a line for each file, preceded by one character indicating the status of the file:

U file
The file already exists in the repository and has not been locally modified; a new revision has been created (if necessary).
N file
The file is a new file which has been added to the repository.
C file
The file already exists in the repository but has been locally modified; you will have to merge the changes.
I file
The file is being ignored (see section Ignoring files via cvsignore).
L file
The file is a symbolic link; at the moment (and for the forseeable future), symbolic links are ignored. (Various options in the `modules' file can be used to recreate symbolic links on checkout, update, etc.; see section The modules file.)

import examples

See section Tracking third-party sources, and See section Creating a directory tree from a number of files.

log--Print out log information for files

Display log information for files. log used to call the RCS utility rlog. Although this is no longer true in the current sources, this history determines the format of the output and the options, which are not quite in the style of the other CVS commands.

The output includes the location of the RCS file, the head revision (the latest revision on the trunk), all symbolic names (tags) and some other things. For each revision, the revision number, the author, the number of lines added/deleted and the log message are printed. All times are displayed in Coordinated Universal Time (UTC). (Other parts of CVS print times in the local timezone).

log options

By default, log prints all information that is available. All other options restrict the output.

-b
Print information about the revisions on the default branch, normally the highest branch on the trunk.
-d dates
Print information about revisions with a checkin date/time in the range given by the semicolon-separated list of dates. The date formats accepted are those accepted by the `-D' option to many other CVS commands (see section Common command options). Dates can be combined into ranges as follows:
d1<d2
d2>d1
Select the revisions that were deposited between d1 and d2.
<d
d>
Select all revisions dated d or earlier.
d<
>d
Select all revisions dated d or later.
d
Select the single, latest revision dated d or earlier.
The `>' or `<' characters may be followed by `=' to indicate an inclusive range rather than an exclusive one. Note that the separator is a semicolon (;).
-h
Print only the RCS pathname, working pathname, head, default branch, access list, locks, symbolic names, and suffix.
-l
Local; run only in current working directory. (Default is to run recursively).
-N
Do not print the list of tags for this file. This option can be very useful when your site uses a lot of tags, so rather than "more"'ing over 3 pages of tag information, the log information is presented without tags at all.
-R
Print only the name of the RCS history file.
-rrevisions
Print information about revisions given in the comma-separated list revisions of revisions and ranges. The following table explains the available range formats:
rev1:rev2
Revisions rev1 to rev2 (which must be on the same branch).
:rev
Revisions from the beginning of the branch up to and including rev.
rev:
Revisions starting with rev to the end of the branch containing rev.
branch
An argument that is a branch means all revisions on that branch.
branch1:branch2
A range of branches means all revisions on the branches in that range.
branch.
The latest revision in branch.
A bare `-r' with no revisions means the latest revision on the default branch, normally the trunk. There can be no space between the `-r' option and its argument.
-s states
Print information about revisions whose state attributes match one of the states given in the comma-separated list states.
-t
Print the same as `-h', plus the descriptive text.
-wlogins
Print information about revisions checked in by users with login names appearing in the comma-separated list logins. If logins is omitted, the user's login is assumed. There can be no space between the `-w' option and its argument.

log prints the intersection of the revisions selected with the options `-d', `-s', and `-w', intersected with the union of the revisions selected by `-b' and `-r'.

log examples

Contributed examples are gratefully accepted.

rdiff---'patch' format diffs between releases

Builds a Larry Wall format patch(1) file between two releases, that can be fed directly into the patch program to bring an old release up-to-date with the new release. (This is one of the few CVS commands that operates directly from the repository, and doesn't require a prior checkout.) The diff output is sent to the standard output device.

You can specify (using the standard `-r' and `-D' options) any combination of one or two revisions or dates. If only one revision or date is specified, the patch file reflects differences between that revision or date and the current head revisions in the RCS file.

Note that if the software release affected is contained in more than one directory, then it may be necessary to specify the `-p' option to the patch command when patching the old sources, so that patch is able to find the files that are located in other directories.

rdiff options

These standard options are supported by rdiff (see section Common command options, for a complete description of them):

-D date
Use the most recent revision no later than date.
-f
If no matching revision is found, retrieve the most recent revision (instead of ignoring the file).
-l
Local; don't descend subdirectories.
-r tag
Use revision tag.

In addition to the above, these options are available:

-c
Use the context diff format. This is the default format.
-s
Create a summary change report instead of a patch. The summary includes information about files that were changed or added between the releases. It is sent to the standard output device. This is useful for finding out, for example, which files have changed between two dates or revisions.
-t
A diff of the top two revisions is sent to the standard output device. This is most useful for seeing what the last change to a file was.
-u
Use the unidiff format for the context diffs. This option is not available if your diff does not support the unidiff format. Remember that old versions of the patch program can't handle the unidiff format, so if you plan to post this patch to the net you should probably not use `-u'.
-V vn
Expand RCS keywords according to the rules current in RCS version vn (the expansion format changed with RCS version 5).

rdiff examples

Suppose you receive mail from foo@bar.com asking for an update from release 1.2 to 1.4 of the tc compiler. You have no such patches on hand, but with CVS that can easily be fixed with a command such as this:

$ cvs rdiff -c -r FOO1_2 -r FOO1_4 tc | \
$$ Mail -s 'The patches you asked for' foo@bar.com

Suppose you have made release 1.3, and forked a branch called `R_1_3fix' for bugfixes. `R_1_3_1' corresponds to release 1.3.1, which was made some time ago. Now, you want to see how much development has been done on the branch. This command can be used:

$ cvs patch -s -r R_1_3_1 -r R_1_3fix module-name
cvs rdiff: Diffing module-name
File ChangeLog,v changed from revision 1.52.2.5 to 1.52.2.6
File foo.c,v changed from revision 1.52.2.3 to 1.52.2.4
File bar.h,v changed from revision 1.29.2.1 to 1.2

release--Indicate that a Module is no longer in use

This command is meant to safely cancel the effect of `cvs checkout'. Since CVS doesn't lock files, it isn't strictly necessary to use this command. You can always simply delete your working directory, if you like; but you risk losing changes you may have forgotten, and you leave no trace in the CVS history file (see section The history file) that you've abandoned your checkout.

Use `cvs release' to avoid these problems. This command checks that no uncommitted changes are present; that you are executing it from immediately above a CVS working directory; and that the repository recorded for your files is the same as the repository defined in the module database.

If all these conditions are true, `cvs release' leaves a record of its execution (attesting to your intentionally abandoning your checkout) in the CVS history log.

release options

The release command supports one command option:

-d
Delete your working copy of the file if the release succeeds. If this flag is not given your files will remain in your working directory. Warning: The release command deletes all directories and files recursively. This has the very serious side-effect that any directory that you have created inside your checked-out sources, and not added to the repository (using the add command; see section Adding files to a directory) will be silently deleted--even if it is non-empty!

release output

Before release releases your sources it will print a one-line message for any file that is not up-to-date.

Warning: Any new directories that you have created, but not added to the CVS directory hierarchy with the add command (see section Adding files to a directory) will be silently ignored (and deleted, if `-d' is specified), even if they contain files.

U file
There exists a newer revision of this file in the repository, and you have not modified your local copy of the file.
A file
The file has been added to your private copy of the sources, but has not yet been committed to the repository. If you delete your copy of the sources this file will be lost.
R file
The file has been removed from your private copy of the sources, but has not yet been removed from the repository, since you have not yet committed the removal. See section commit--Check files into the repository.
M file
The file is modified in your working directory. There might also be a newer revision inside the repository.
? file
file is in your working directory, but does not correspond to anything in the source repository, and is not in the list of files for CVS to ignore (see the description of the `-I' option, and see section Ignoring files via cvsignore). If you remove your working sources, this file will be lost. Note that no warning message like this is printed for spurious directories that CVS encounters. The directory, and all its contents, are silently ignored.

release examples

Release the module, and delete your local working copy of the files.

$ cd ..         # You must stand immediately above the
                # sources when you issue `cvs release'.
$ cvs release -d tc
You have [0] altered files in this repository.
Are you sure you want to release (and delete) module `tc': y
$

rtag--Add a symbolic tag to a module

You can use this command to assign symbolic tags to particular, explicitly specified source revisions in the repository. rtag works directly on the repository contents (and requires no prior checkout). Use tag instead (see section tag--Add a symbolic tag to checked out versions of files), to base the selection of revisions on the contents of your working directory.

If you attempt to use a tag name that already exists, CVS will complain and not overwrite that tag. Use the `-F' option to force the new tag value.

rtag options

These standard options are supported by rtag (see section Common command options, for a complete description of them):

-D date
Tag the most recent revision no later than date.
-f
Only useful with the `-D date' or `-r tag' flags. If no matching revision is found, use the most recent revision (instead of ignoring the file).
-F
Overwrite an existing tag of the same name on a different revision. This option is new in CVS 1.4. The old behavior is matched by `cvs tag -F'.
-l
Local; run only in current working directory.
-n
Do not run any tag program that was specified with the `-t' flag inside the `modules' file. (see section The modules file).
-R
Commit directories recursively. This is on by default.
-r tag
Only tag those files that contain tag. This can be used to rename a tag: tag only the files identified by the old tag, then delete the old tag, leaving the new tag on exactly the same files as the old tag.

In addition to the above common options, these options are available:

-a
Use the `-a' option to have rtag look in the `Attic' (see section Removing files from a module) for removed files that contain the specified tag. The tag is removed from these files, which makes it convenient to re-use a symbolic tag as development continues (and files get removed from the up-coming distribution).
-b
Make the tag a branch tag. See section Branches.
-d
Delete the tag instead of creating it. In general, tags (often the symbolic names of software distributions) should not be removed, but the `-d' option is available as a means to remove completely obsolete symbolic names if necessary (as might be the case for an Alpha release, or if you mistagged a module).

status--Display status information on checked out files

Display a brief report on the current status of files with respect to the source repository. For information on the basic output see section File status. For information on the Sticky tag and Sticky date output, see section Sticky tags. For information on the Sticky options output, see the `-k' option in section update options.

You can also use this command to determine the potential impact of a `cvs update' on your working source directory--but remember that things might change in the repository before you run update.

status options

These standard options are supported by status (see section Common command options, for a complete description of them):

-l
Local; run only in current working directory.
-R
Commit directories recursively. This is on by default.

There is one additional option:

-v
Verbose. In addition to the information normally displayed, print all symbolic tags, together with the numerical value of the revision or branch they refer to. For more information, see section Tags--Symbolic revisions

tag--Add a symbolic tag to checked out versions of files

Use this command to assign symbolic tags to the nearest repository versions to your working sources. The tags are applied immediately to the repository, as with rtag, but the versions are supplied implicitly by the CVS records of your working files' history rather than applied explicitly.

One use for tags is to record a snapshot of the current sources when the software freeze date of a project arrives. As bugs are fixed after the freeze date, only those changed sources that are to be part of the release need be re-tagged.

The symbolic tags are meant to permanently record which revisions of which files were used in creating a software distribution. The checkout and update commands allow you to extract an exact copy of a tagged release at any time in the future, regardless of whether files have been changed, added, or removed since the release was tagged.

This command can also be used to delete a symbolic tag, or to create a branch. See the options section below.

If you attempt to use a tag name that already exists, CVS will complain and not overwrite that tag. Use the `-F' option to force the new tag value.

tag options

These standard options are supported by tag (see section Common command options, for a complete description of them):

-F
Overwrite an existing tag of the same name on a different revision. This option is new in CVS 1.4. The old behavior is matched by `cvs tag -F'.
-l
Local; run only in current working directory.
-R
Commit directories recursively. This is on by default.

Two special options are available:

-b
The -b option makes the tag a branch tag (see section Branches), allowing concurrent, isolated development. This is most useful for creating a patch to a previously released software distribution.
-c
The -c option checks that all files which are to be tagged are unmodified. This can be used to make sure that you can reconstruct the current file contents.
-d
Delete a tag. If you use `cvs tag -d symbolic_tag', the symbolic tag you specify is deleted instead of being added. Warning: Be very certain of your ground before you delete a tag; doing this permanently discards some historical information, which may later turn out to be valuable.

update--Bring work tree in sync with repository

After you've run checkout to create your private copy of source from the common repository, other developers will continue changing the central source. From time to time, when it is convenient in your development process, you can use the update command from within your working directory to reconcile your work with any revisions applied to the source repository since your last checkout or update.

update options

These standard options are available with update (see section Common command options, for a complete description of them):

-D date
Use the most recent revision no later than date. This option is sticky, and implies `-P'. See section Sticky tags, for more information on sticky tags/dates.
-f
Only useful with the `-D date' or `-r tag' flags. If no matching revision is found, retrieve the most recent revision (instead of ignoring the file).
-k kflag
Process RCS keywords according to kflag. See co(1). This option is sticky; future updates of this file in this working directory will use the same kflag. The status command can be viewed to see the sticky options. See section status--Display status information on checked out files.
-l
Local; run only in current working directory. See section Recursive behavior.
-P
Prune empty directories.
-p
Pipe files to the standard output.
-R
Operate recursively. This is on by default. See section Recursive behavior.
-r tag
Retrieve revision tag. This option is sticky, and implies `-P'. See section Sticky tags, for more information on sticky tags/dates.

These special options are also available with update.

-A
Reset any sticky tags, dates, or `-k' options. See section Sticky tags, for more information on sticky tags/dates.
-d
Create any directories that exist in the repository if they're missing from the working directory. Normally, update acts only on directories and files that were already enrolled in your working directory. This is useful for updating directories that were created in the repository since the initial checkout; but it has an unfortunate side effect. If you deliberately avoided certain directories in the repository when you created your working directory (either through use of a module name or by listing explicitly the files and directories you wanted on the command line), then updating with `-d' will create those directories, which may not be what you want.
-I name
Ignore files whose names match name (in your working directory) during the update. You can specify `-I' more than once on the command line to specify several files to ignore. Use `-I !' to avoid ignoring any files at all. See section Ignoring files via cvsignore, for other ways to make CVS ignore some files.
-Wspec
Specify file names that should be filtered during update. You can use this option repeatedly. spec can be a file name pattern of the same type that you can specify in the `.cvswrappers' file. See section The cvswrappers file.
-jrevision
With two `-j' options, merge changes from the revision specified with the first `-j' option to the revision specified with the second `j' option, into the working directory. With one `-j' option, merge changes from the ancestor revision to the revision specified with the `-j' option, into the working directory. The ancestor revision is the common ancestor of the revision which the working directory is based on, and the revision specified in the `-j' option. In addition, each -j option can contain an optional date specification which, when used with branches, can limit the chosen revision to one within a specific date. An optional date is specified by adding a colon (:) to the tag: `-jSymbolic_Tag:Date_Specifier'. See section Merging.

update output

update and checkout keep you informed of its progress by printing a line for each file, preceded by one character indicating the status of the file:

U file
The file was brought up to date with respect to the repository. This is done for any file that exists in the repository but not in your source, and for files that you haven't changed but are not the most recent versions available in the repository.
A file
The file has been added to your private copy of the sources, and will be added to the source repository when you run commit on the file. This is a reminder to you that the file needs to be committed.
R file
The file has been removed from your private copy of the sources, and will be removed from the source repository when you run commit on the file. This is a reminder to you that the file needs to be committed.
M file
The file is modified in your working directory. `M' can indicate one of two states for a file you're working on: either there were no modifications to the same file in the repository, so that your file remains as you last saw it; or there were modifications in the repository as well as in your copy, but they were merged successfully, without conflict, in your working directory. CVS will print some messages if it merges your work, and a backup copy of your working file (as it looked before you ran update) will be made. The exact name of that file is printed while update runs.
C file
A conflict was detected while trying to merge your changes to file with changes from the source repository. file (the copy in your working directory) is now the output of the rcsmerge(1) command on the two revisions; an unmodified copy of your file is also in your working directory, with the name `.#file.revision' where revision is the RCS revision that your modified file started from. Resolve the conflict as described in section Conflicts example (Note that some systems automatically purge files that begin with `.#' if they have not been accessed for a few days. If you intend to keep a copy of your original file, it is a very good idea to rename it.) Under VMS, the file name starts with `__' rather than `.#'.
? file
file is in your working directory, but does not correspond to anything in the source repository, and is not in the list of files for CVS to ignore (see the description of the `-I' option, and see section Ignoring files via cvsignore). Note that no warning message like this is printed for spurious directories that CVS encounters. The directory, and all its contents, are silently ignored.

update examples

The following line will display all files which are not up-to-date without actually change anything in your working directory. It can be used to check what has been going on with the project.

$ cvs -n -q update


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