CVS(1)

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NAME
cvs - Concurrent Versions System

SYNOPSIS

cvs [ cvs_options ]
    cvs_command [ command_options ] [ command_args ]

NOTE
This manpage is a summary of some of the features of cvs but it may no longer be kept up-to-date. For more current and in-depth documentation, please consult the Cederqvist manual (via the info cvs command or otherwise, as described in the SEE ALSO section of this manpage).

DESCRIPTION
CVS is a version control system, which allows you to keep old versions of files (usually source code), keep a log of who, when, and why changes occurred, etc., like RCS or SCCS. Unlike the simpler systems, CVS does not just operate on one file at a time or one directory at a time, but operates on hierarchical collections of directories consisting of version controlled files. CVS helps to manage releases and to control the concurrent editing of source files among multiple authors. CVS allows triggers to enable/log/control various operations and works well over a wide area network. cvs keeps a single copy of the master sources. This copy is called the source ``repository''; it contains all the information to permit extracting previous software releases at any time based on either a symbolic revision tag, or a date in the past.

ESSENTIAL COMMANDS
cvs provides a rich variety of commands (cvs_command in the Synopsis), each of which often has a wealth of options, to satisfy the many needs of source management in distributed environments. However, you don't have to master every detail to do useful work with cvs; in fact, five commands are sufficient to use (and contribute to) the source repository.

cvs checkout modules...
    A necessary preliminary for most cvs work: creates your private copy of the source for modules (named collections of source; you can also use a path relative to the source repository here). You can work with this copy without interfering with others' work. At least one subdirectory level is always created.

cvs update
    Execute this command from within your private source directory when you wish to update your copies of source files from changes that other developers have made to the source in the repository.

cvs add file...
    Use this command to enroll new files in cvs records of your working directory. The files will be added to the repository the next time you run Note: You should use the command to bootstrap new sources into the source repository. is only used for new files to an already checked-out module.

cvs remove file...
    Use this command (after erasing any files listed) to declare that you wish to eliminate files from the repository. The removal does not affect others until you run

cvs commit file...
    Use this command when you wish to ``publish'' your changes to other developers, by incorporating them in the source repository.

OPTIONS
The cvs command line can include cvs_options, which apply to the overall cvs program; a cvs_command, which specifies a particular action on the source repository; and command_options and command_arguments to fully specify what the cvs_command will do. Warning: you must be careful of precisely where you place options relative to the cvs_command. The same option can mean different things depending on whether it is in the cvs_options position (to the left of a cvs command) or in the command_options position (to the right of a cvs command). There are only two situations where you may omit cvs_command: or elicits a list of available commands, and or displays version information on cvs itself.

CVS OPTIONS
As of release 1.6, cvs supports GNU style long options as well as short options. Only a few long options are currently supported, these are listed in brackets after the short options whose functions they duplicate. Use these options to control the overall cvs program:

-H [ --help ]
    Display usage information about the specified cvs_command (but do not actually execute the command). If you don't specify a command name, displays a summary of all the commands available.

-Q  Causes the command to be really quiet; the command will generate output only for serious problems.

-q  Causes the command to be somewhat quiet; informational messages, such as reports of recursion through subdirectories, are suppressed.

-b bindir
    Use bindir as the directory where RCS programs are located (CVS 1.9 and older). Overrides the setting of the RCSBIN environment variable. This value should be specified as an absolute pathname.

-d CVS_root_directory
    Use CVS_root_directory as the root directory pathname of the master source repository. Overrides the setting of the CVSROOT environment variable. This value should be specified as an absolute pathname.

-e editor
    Use editor to enter revision log information. Overrides the setting of the CVSEDITOR , VISUAL , and EDITOR environment variables.

-f  Do not read the cvs startup file (~/.cvsrc).

-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.

-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.

-r  Makes new working files read-only. Same effect as if the CVSREAD environment variable is set.

-R  Turns on read-only repository mode. This allows one to check out from a read-only repository, such as within an anoncvs server, or from a CDROM repository. Same effect as if the CVSREADONLYFS environment variable is set. Using -R can also considerably speed up checkout's over NFS.

-v [ --version ]
    Displays version and copyright information for cvs.

-w  Makes new working files read-write (default). Overrides the setting of the CVSREAD environment variable.

-g  Forces group-write perms on working files. This option is typically used when you have multiple users sharing a single checked out source tree, allowing them to operate their shells with a less dangerous umask. To use this feature, create a directory to hold the checked-out source tree, set it to a private group, and set up the directory such that files created under it inherit the group id of the directory. This occurs automatically with FreeBSD. With SysV you must typically set the SGID bit on the directory. The users who are to share the checked out tree must be placed in that group. Note that the sharing of a single checked-out source tree is very different from giving several users access to a common CVS repository. Access to a common CVS repository already maintains shared group-write perms and does not require this option. To use the option transparently, simply place the line 'cvs -g' in your ~/.cvsrc file. Doing this is not recommended unless you firewall all your source checkouts within a private group or within a private mode 0700 directory.

-x  Encrypt all communication between the client and the server. As of this writing, this is only implemented when using a Kerberos connection.

-z compression-level
    When transferring files across the network use gzip with compression level compression-level to compress and de-compress data as it is transferred. Requires the presence of the GNU gzip program in the current search path at both ends of the link.

USAGE
Except when requesting general help with you must specify a cvs_command to cvs to select a specific release control function to perform. Each cvs command accepts its own collection of options and arguments. However, many options are available across several commands. You can display a usage summary for each command by specifying the -H option with the command.

CVS STARTUP FILE
Normally, when CVS starts up, it reads the .cvsrc file from the home directory of the user reading it. This startup procedure can be turned off with the -f flag. The .cvsrc file lists CVS commands with a list of arguments, one command per line. For example, the following line in .cvsrc: diff -c will mean that the command will always be passed the -c option in addition to any other options that are specified in the command line (in this case it will have the effect of producing context sensitive diffs for all executions of ). Global options are specified using the cvs keyword. For example, the following: cvs -q will mean that all commands will behave as thought he -q global option had been supplied.

CVS COMMAND SUMMARY
Here are brief descriptions of all the cvs commands:

add Add a new file or directory to the repository, pending a on the same file. Can only be done from within sources created by a previous invocation. Use to place whole new hierarchies of sources under cvs control. (Does not directly affect repository; changes working directory.)

admin
    Execute control functions on the source repository. (Changes repository directly; uses working directory without changing it.)

checkout
    Make a working directory of source files for editing. (Creates or changes working directory.)

commit
    Apply to the source repository changes, additions, and deletions from your working directory. (Changes repository.)

diff
    Show differences between files in working directory and source repository, or between two revisions in source repository. (Does not change either repository or working directory.)

export
    Prepare copies of a set of source files for shipment off site. Differs from in that no cvs administrative directories are created (and therefore cannot be executed from a directory prepared with and a symbolic tag must be specified. (Does not change repository; creates directory similar to working directories).

history
    Show reports on cvs commands that you or others have executed on a particular file or directory in the source repository. (Does not change repository or working directory.) History logs are kept only if enabled by creation of the file; see cvs(5).

import
    Incorporate a set of updates from off-site into the source repository, as a ``vendor branch''. (Changes repository.)

init
    Initialize a repository by adding the CVSROOT subdirectory and some default control files. You must use this command or initialize the repository in some other way before you can use it.

log Display log information. (Does not change repository or working directory.)

rdiff
    Prepare a collection of diffs as a patch file between two releases in the repository. (Does not change repository or working directory.)

release
    Cancel a abandoning any changes. (Can delete working directory; no effect on repository.)

remove
    Remove files from the source repository, pending a on the same files. (Does not directly affect repository; changes working directory.)

rtag
    Explicitly specify a symbolic tag for particular revisions of files in the source repository. See also (Changes repository directly; does not require or affect working directory.)

status
    Show current status of files: latest version, version in working directory, whether working version has been edited and, optionally, symbolic tags in the RCS file. (Does not change repository or working directory.)

tag Specify a symbolic tag for files in the repository. By default, tags the revisions that were last synchronized with your working directory. (Changes repository directly; uses working directory without changing it.)

update
    Bring your working directory up to date with changes from the repository. Merges are performed automatically when possible; a warning is issued if manual resolution is required for conflicting changes. (Changes working directory; does not change repository.)

COMMON COMMAND OPTIONS
This section describes the command_options that are available across several cvs commands. 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 count on the same meaning for the option as in other commands. (Other command options, which are listed with the individual commands, may have different meanings from one cvs command to another.) 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 (a single argument, date description specifying a date in the past). A wide variety of date formats are supported, in particular ISO ("1972-09-24 20:05") or Internet ("24 Sep 1972 20:05"). The date_spec is interpreted as being in the local timezone, unless a specific timezone is specified. 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 (unless you explicitly override it; see the description of the update command). -D is available with the checkout, diff, history, export, rdiff, rtag, and update commands. 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

-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 on 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 version is used in this situation.) -f is available with these commands: checkout, export, rdiff, rtag, and update.

-k kflag
    Alter the default processing of keywords. The -k option is available with the add, checkout, diff, rdiff, export, and BR update commands. 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. Some of the more useful kflags are -ko and -kb (for binary files), and -kv which is useful for an export where you wish to retain keyword information after an import at some other site.

-l  Local; run only in current working directory, rather than recurring through subdirectories. Available with the following commands: checkout, commit, diff, export, remove, rdiff, rtag, status, tag, and update.

-n  Do not run any checkout/commit/tag/update program. (A program can be specified to run on each of these activities, in the modules database; this option bypasses it.) Available with the checkout, export, and rtag commands. Warning: this is not the same as the overall option, which you can specify to the left of a cvs command!

-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.

-T  Create/Update CVS/Template by copying it from the (local) repository. This option is useful for developers maintaining a local cvs repository but committing to a remote repository. By maintaining CVS/Template the remote commits will still be able to bring up the proper template in the commit editor session. Available with the checkout and update commands.

-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.

-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: refers to the most recent version available in the repository, and refers to the revision you last checked out into the current working directory. The tag specification is ``sticky'' when you use this option with or 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. tag can be either a symbolic or numeric tag. When a command expects a specific revision, the name of a branch is interpreted as the most recent revision on that branch. Specifying the -q global option along with the -r command option is often useful, to suppress the warning messages when the RCS file does not contain the specified tag. -r is available with the annotate, checkout, commit, diff, history, export, rdiff, rtag, and update commands. Warning: this is not the same as the overall option, which you can specify to the left of a cvs command!

CVS COMMANDS
Here (finally) are details on all the cvs commands and the options each accepts. The summary lines at the top of each command's description highlight three kinds of things:

Command Options and Arguments
    Special options are described in detail below; common command options may appear only in the summary line.

Working Directory, or Repository?
    Some cvs commands require a working directory to operate; some require a repository. Also, some commands change the repository, some change the working directory, and some change nothing.

Synonyms
    Many commands have synonyms, which you may find easier to remember (or type) than the principal name.

add [-k kflag] [-m 'message'] files...
    Requires: repository, working directory.
    Changes: working directory.
    Synonym: new
    Use the add command to create a new file or directory in the source repository. The files or directories specified with add must already exist in the current directory (which must have been created with the checkout command). To add a whole new directory hierarchy to the source repository (for example, files received from a third-party vendor), use the command instead. If the argument to refers to an immediate sub-directory, the directory is created at the correct place in the source repository, and the necessary cvs administration files are created in your working directory. If the directory already exists in the source repository, still creates the administration files in your version of the directory. This allows you to use to add a particular directory to your private sources even if someone else created that directory after your checkout of the sources. You can do the following:
    example% mkdir new_directory
    example% cvs add new_directory
    example% cvs update new_directory
    An alternate approach using might be:
    example% cvs update -d new_directory
    (To add any available new directories to your working directory, it's probably simpler to use or The added files are not placed in the source repository until you use to make the change permanent. Doing a on a file that was removed with the command will resurrect the file, if no command intervened. You will have the opportunity to specify a logging message, as usual, when you use to make the new file permanent. If you'd like to have another logging message associated with just creation of the file (for example, to describe the file's purpose), you can specify it with the option to the add command. The option specifies the default way that this file will be checked out. The argument is stored in the RCS file and can be changed with Specifying is useful for checking in binaries that shouldn't have keywords expanded.

admin [rcs-options] files...
    Requires: repository, working directory.
    Changes: repository.
    Synonym: rcs
    This is the cvs interface to assorted administrative facilities, similar to rcs(1). This command works recursively, so extreme care should be used.

checkout [options] modules...
    Requires: repository.
    Changes: working directory.
    Synonyms: co, get
    Make a working directory containing copies of the source files specified by modules. You must execute before using most of the other cvs commands, since most of them operate on your working directory. modules are either symbolic names (themselves defined as the module in the source repository; see cvs(5)) for some collection of source directories and files, or paths to directories or files in the repository. 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 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). Running 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 described below. The options permitted with include the standard command options -P, -f, -k kflag , -l, -n, -p, -r tag, and -D date . In addition to those, you can use these special command options with checkout: Use the -A option to reset any sticky tags, dates, or -k options. (If you get a working file using one of the -r, -D, or -k options, cvs remembers the corresponding tag, date, or kflag and continues using it on future updates; use the -A option to make cvs forget these specifications, and retrieve the ``head'' version of the file). Does not reset sticky -k options on modified files. The -j branch option merges the changes made between the resulting revision and the revision that it is based on (e.g., if the tag refers to a branch, cvs will merge all changes made in that branch into your working file). With two -j options, cvs will merge in the changes between the two respective revisions. This can be used to ``remove'' a certain delta from your working file. In addition, each -j option can contain on 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. An example might be what tells you to do when you have just imported sources that have conflicts with local changes:
    example% cvs checkout -jTAG:yesterday -jTAG module
    Use the -N option with to avoid shortening module paths in your working directory. (Normally, cvs shortens paths as much as possible when you specify an explicit target directory.) Use the -c option to copy the module file, sorted, to the standard output, instead of creating or modifying any files or directories in your working directory. Use the -d dir option to 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. Use the -s option to display per-module status information stored with the -s option within the modules file.

commit [-lR] [-m 'log_message' | -F file] [-r revision] [files...]
    Requires: working directory, repository.
    Changes: repository.
    Synonym: ci
    Use when you want to incorporate changes from your working source files into the general 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. Sometimes you may want to force a file to be committed even though it is unchanged; this is achieved with the -f flag, which also has the effect of disabling recursion (you can turn it back on with -R of course). 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 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 and placed in the source repository file. You can instead specify the log message on the command line with the -m option, thus suppressing the editor invocation, or use the -F option to specify that the argument file contains the log message. The -r option can be used to commit to a particular symbolic or numeric revision. For example, to bring all your files up to the revision ``3.0'' (including those that haven't changed), you might do:
    example% cvs commit -r3.0
    cvs will only allow you to commit to a revision that is on the main trunk (a revision with a single dot). However, you can also commit to a branch revision (one that has an even number of dots) with the -r option. To create a branch revision, one typically use the -b option of the rtag or tag commands. 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 perturbing 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:
    example% cvs rtag -b -rFCS1_2 FCS1_2_Patch product_module
    example% cvs checkout -rFCS1_2_Patch product_module
    example% cd product_module
    [[ hack away ]]
    example% cvs commit
    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:
    example% cvs tag -b EXPR1
    example% cvs update -rEXPR1
    [[ hack away ]]
    example% cvs commit
    Others would simply do to work with you on the experimental change.

diff [-kl] [format_options] [[-r rev1 | -D date1 | -j rev1:date1] [-r rev2 | -D date2 | -j rev2:date2]] [files...]
    Requires: working directory, repository.
    Changes: nothing.
    You can compare your working files with revisions in the source repository, with the command. If you don't specify a particular revision, your files are compared with the revisions they were based on. You can also use the standard cvs command option -r to specify a particular revision to compare your files with. Finally, if you use -r twice, you can see differences between two revisions in the repository. You can also specify -D options to diff against a revision (on the head branch) in the past, and you can also specify -j options to diff against a revision relative to a branch tag in the past. The -r and -D and -j options can be mixed together with at most two options ever specified. See for a list of supported format_options. If you don't specify any files, diff will display differences for all those files in the current directory (and its subdirectories, unless you use the standard option -l) that differ from the corresponding revision in the source repository (i.e. files that you have changed), or that differ from the revision specified.

export [-flNnQq] -r rev|-D date [-d dir] [-k kflag] module...
    Requires: repository.
    Changes: current directory.
    This command is a variant of use it when you want a copy of the source for module without the cvs administrative directories. For example, you might use 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. The only non-standard options are (write the source into directory dir) and (don't shorten module paths). These have the same meanings as the same options in The -kv option is useful when export is used. This causes any keywords to be expanded such that an import done at some other site will not lose the keyword revision information. Other kflags may be used with and are described in co(1).

history [-report] [-flags] [-options args] [files...]
    Requires: the file
    Changes: nothing.
    cvs keeps a history file that tracks each use of the checkout, commit, rtag, update, and release commands. You can use to display this information in various formats. Warning: uses and in ways that conflict with the descriptions in COMMON COMMAND 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).

-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 X from the cvs history. The types are indicated by single letters, which you may specify in combination. Certain commands have a single record type: checkout (type `O'), release (type `F'), and rtag (type `T'). One of four record types may result from an update: `W', when the working copy of a file is deleted during update (because it was gone from the repository); `U', when a working file was copied from the repository; `G', when a merge was necessary and it succeeded; and 'C', when a merge was necessary but collisions were detected (requiring manual merging). Finally, one of three record types results from commit: `M', when a file was modified; `A', when a file is first added; and `R', when a file is removed.

-e  Everything (all record types); equivalent to specifying

-z zone
    Use time zone zone when outputting history records. The zone name LT stands for local time; numeric offsets stand for hours and minutes ahead of UTC. For example, +0530 stands for 5 hours and 30 minutes ahead of (i.e. east of) UTC.

    The options shown as -flags constrain the report without requiring option arguments:

-a  Show data for all users (the default is to show data only for the user executing

-l  Show last modification only.

-w  Show only the records for modifications done from the same working directory where 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.

-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 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 [-options] repository vendortag releasetag...
    Requires: Repository, source distribution directory.
    Changes: repository.
    Use 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 form the outside source. 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 to reconcile the differences, as import instructs you to do. By default, certain file names are ignored during names associated with CVS administration, or with other common source control systems; common names for patch files, object files, archive files, and editor backup files; and other names that are usually artifacts of assorted utilities. For an up to date list of ignored file names, see the Cederqvist manual (as described in the SEE ALSO section of this manpage). The outside source is saved in a first-level branch, by default Updates are leaves of this branch; for example, files from the first imported collection of source will be revision then files from the first imported update will be revision 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 You must also specify at least one releasetag to uniquely identify the files at the leaves created each time you execute The releasetag should be new, not previously existing in the repository file, and uniquely identify the imported release. One of the standard cvs command options is available: -m message. If you do not specify a logging message with -m, your editor is invoked (as with commit) to allow you to enter one. There are three additional special options. Use to specify that each file's time of last modification should be used for the checkin date and time. Use to specify a first-level branch other than Use to 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

log [-l] rlog-options [files...]
    Requires: repository, working directory.
    Changes: nothing.
    Synonym: rlog
    Display log information for files. Among the more useful options are -h to display only the header (including tag definitions, but omitting most of the full log); -r to select logs on particular revisions or ranges of revisions; and -d to select particular dates or date ranges. See rlog(1) for full explanations. This command is recursive by default, unless the -l option is specified.

rdiff [-flags] [-V vn] [-r t|-D d [-r t2|-D d2]] modules...
    Requires: repository.
    Changes: nothing.
    Synonym: patch
    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. The standard option flags -f, and -l are available with this command. There are also several special option flags: If you use the -s option, no patch output is produced. Instead, a summary of the changed or added files between the two releases is sent to the standard output device. This is useful for finding out, for example, which files have changed between two dates or revisions. If you use the -t option, 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. If you use the -u option, the patch output uses the newer ``unidiff'' format for context diffs. You can use -c to explicitly specify the form of context diffs (which is the default), if you like.

release [-dQq] modules...
    Requires: Working directory.
    Changes: Working directory, history log.
    This command is meant to safely cancel the effect of 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 that you've abandoned your checkout. Use to avoid these problems. This command checks that no un-committed changes are present; that you are executing it from immediately above, or inside, 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, leaves a record of its execution (attesting to your intentionally abandoning your checkout) in the cvs history log. You can use the -d flag to request that your working copies of the source files be deleted if the release succeeds.

remove [-lR] [files...]
    Requires: Working directory.
    Changes: Working directory.
    Synonyms: rm, delete
    Use this command to declare that you wish to remove files from the source repository. Like most cvs commands, works on files in your working directory, not directly on the repository. As a safeguard, it also requires that you first erase the specified files from your working directory. The files are not actually removed until you apply your changes to the repository with commit; at that point, the corresponding RCS files in the source repository are moved into the directory (also within the source repository). This command is recursive by default, scheduling all physically removed files that it finds for removal by the next commit. Use the -l option to avoid this recursion, or just specify that actual files that you wish remove to consider.

rtag [-falnRQq] [-b] [-d] [-r tag | -D date] symbolic_tag modules...
    Requires: repository.
    Changes: repository.
    Synonym: rfreeze
    You can use this command to assign symbolic tags to particular, explicitly specified source versions in the repository. works directly on the repository contents (and requires no prior checkout). Use instead, to base the selection of versions to tag on the contents of your working directory. 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, say). will not move a tag that already exists. With the -F option, however, will re-locate any instance of symbolic_tag that already exists on that file to the new repository versions. Without the -F option, attempting to use to apply a tag that already exists on that file will produce an error message. The -b option makes the tag a ``branch'' tag, allowing concurrent, isolated development. This is most useful for creating a patch to a previously released software distribution. You can use the standard -r and -D options to tag only those files that already contain a certain tag. This method would 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. rtag executes recursively by default, tagging all subdirectories of modules you specify in the argument. You can restrict its operation to top-level directories with the standard -l option; or you can explicitly request recursion with -R. The modules database can specify a program to execute whenever a tag is specified; a typical use is to send electronic mail to a group of interested parties. If you want to bypass that program, use the standard -n option. Use the -a option to have rtag look in the 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).

status [-lRqQ] [-v] [files...]
    Requires: working directory, repository.
    Changes: nothing.
    Display a brief report on the current status of files with respect to the source repository, including any ``sticky'' tags, dates, or -k options. (``Sticky'' options will restrict how operates until you reset them; see the description of You can also use this command to anticipate the potential impact of a on your working source directory. If you do not specify any files explicitly, reports are shown for all files that cvs has placed in your working directory. You can limit the scope of this search to the current directory itself (not its subdirectories) with the standard -l option flag; or you can explicitly request recursive status reports with the -R option. The -v option causes the symbolic tags for the RCS file to be displayed as well.

tag [-lQqR] [-F] [-b] [-d] [-r tag | -D date] [-f] symbolic_tag [files...]
    Requires: working directory, repository.
    Changes: repository.
    Synonym: freeze
    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. One potentially surprising aspect of the fact that cvs tag operates on the repository is that you are tagging the checked-in revisions, which may differ from locally modified files in your working directory. If you want to avoid doing this by mistake, specify the -c option to cvs tag. If there are any locally modified files, CVS will abort with an error before it tags any files. 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, export 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. You can use the standard -r and -D options to tag only those files that already contain a certain tag. This method would 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. Specifying the -f flag in addition to the -r or -D flags will tag those files named on the command line even if they do not contain the old tag or did not exist on the specified date. By default (without a -r or -D flag) the versions to be tagged are supplied implicitly by the cvs records of your working files' history rather than applied explicitly. If you use 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 effectively discards some historical information, which may later turn out to have been valuable. will not move a tag that already exists. With the -F option, however, will re-locate any instance of symbolic_tag that already exists on that file to the new repository versions. Without the -F option, attempting to use to apply a tag that already exists on that file will produce an error message. The -b option makes the tag a ``branch'' tag, allowing concurrent, isolated development. This is most useful for creating a patch to a previously released software distribution. Normally, tag executes recursively through subdirectories; you can prevent this by using the standard -l option, or specify the recursion explicitly by using -R.

update [-ACdflPpQqR] [-d] [-r tag|-D date] files...
    Requires: repository, working directory.
    Changes: working directory.
    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 keeps you informed of its progress by printing a line for each file, prefaced with one of the characters to indicate 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 working directory, and for files that you haven't changed but are not the most recent versions available in the repository.

P file
    Like U, but the CVS server sends a patch instead of an entire file. This accomplishes the same thing as U using less bandwidth.

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 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 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. 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.

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 result of merging the two versions; an unmodified copy of your file is also in your working directory, with the name `.#file.version', where version is the revision that your modified file started from. (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.)

? 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).

    Use the -A option to reset any sticky tags, dates, or -k options. (If you get a working copy of a file by using one of the -r, -D, or -k options, cvs remembers the corresponding tag, date, or kflag and continues using it on future updates; use the -A option to make cvs forget these specifications, and retrieve the ``head'' version of the file). The -jbranch option merges the changes made between the resulting revision and the revision that it is based on (e.g., if the tag refers to a branch, cvs will merge all changes made in that branch into your working file). With two -j options, cvs will merge in the changes between the two respective revisions. This can be used to ``remove'' a certain delta from your working file. E.g., If the file foo.c is based on revision 1.6 and I want to remove the changes made between 1.3 and 1.5, I might do:
    example% cvs update -j1.5 -j1.3 foo.c	# note the order...
    In addition, each -j option can contain on 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
    Use the -d option to 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. Use -I name to 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. By default, update ignores files whose names match certain patterns; for an up to date list of ignored file names, see the Cederqvist manual (as described in the SEE ALSO section of this manpage). Use to avoid ignoring any files at all. Use the option to overwrite locally modified files with clean copies from the repository (the modified file is saved in `.#file.revision', however). The standard cvs command options -f, -k, -l, -P, -p, and -r are also available with update.

FILES
For more detailed information on cvs supporting files, see cvs(5).

Files in home directories:

.cvsrc
    The cvs initialization file. Lines in this file can be used to specify default options for each cvs command. For example the line will ensure that is always passed the -c option in addition to any other options passed on the command line.

.cvswrappers
    Specifies wrappers to be used in addition to those specified in the CVSROOT/cvswrappers file in the repository.

Files in working directories:

CVS A directory of cvs administrative files. Do not delete.

CVS/Entries
    List and status of files in your working directory.

CVS/Entries.Backup
    A backup of

CVS/Entries.Static
    Flag: do not add more entries on

CVS/Root
    Pathname to the repository ( CVSROOT ) location at the time of checkout. This file is used instead of the CVSROOT environment variable if the environment variable is not set. A warning message will be issued when the contents of this file and the CVSROOT environment variable differ. The file may be over-ridden by the presence of the CVS_IGNORE_REMOTE_ROOT environment variable.

CVS/Repository
    Pathname to the corresponding directory in the source repository.

CVS/Tag
    Contains the per-directory ``sticky'' tag or date information. This file is created/updated when you specify -r or -D to the checkout or update commands, and no files are specified.

CVS/Checkin.prog
    Name of program to run on

CVS/Update.prog
    Name of program to run on

Files in source repositories:

$CVSROOT/CVSROOT
    Directory of global administrative files for repository.

CVSROOT/commitinfo,v
    Records programs for filtering requests.

CVSROOT/cvswrappers,v
    Records cvs wrapper commands to be used when checking files into and out of the repository. Wrappers allow the file or directory to be processed on the way in and out of CVS. The intended uses are many, one possible use would be to reformat a C file before the file is checked in, so all of the code in the repository looks the same.

CVSROOT/editinfo,v
    Records programs for editing/validating log entries.

CVSROOT/history
    Log file of cvs transactions.

CVSROOT/loginfo,v
    Records programs for piping log entries.

CVSROOT/modules,v
    Definitions for modules in this repository.

CVSROOT/rcsinfo,v
    Records pathnames to templates used during a operation.

CVSROOT/taginfo,v
    Records programs for validating/logging and operations.

MODULE/Attic
    Directory for removed source files.

#cvs.lock
    A lock directory created by cvs when doing sensitive changes to the source repository.

#cvs.tfl.pid
    Temporary lock file for repository.

#cvs.rfl.pid
    A read lock.

#cvs.wfl.pid
    A write lock.

ENVIRONMENT

CVSROOT
    Should contain the full pathname to the root of the cvs source repository (where the RCS files are kept). This information must be available to cvs for most commands to execute; if CVSROOT is not set, or if you wish to override it for one invocation, you can supply it on the command line: You may not need to set CVSROOT if your cvs binary has the right path compiled in.

CVSREAD
    If this is set, checkout and update will try hard to make the files in your working directory read-only. When this is not set, the default behavior is to permit modification of your working files.

CVSREADONLYFS
    If this is set, the -R option is assumed, and cvs operates in read-only repository mode.

RCSBIN
    Specifies the full pathname where to find RCS programs, such as co(1) and ci(1) (CVS 1.9 and older).

CVSEDITOR
    Specifies the program to use for recording log messages during commit. If not set, the VISUAL and EDITOR environment variables are tried (in that order). If neither is set, a system-dependent default editor (e.g., vi) is used.

CVS_CLIENT_PORT
    If this variable is set then cvs will use this port in pserver mode rather than the default port (cvspserver 2401).

CVS_IGNORE_REMOTE_ROOT
    If this variable is set then cvs will ignore all references to remote repositories in the CVS/Root file.

CVS_OPTIONS
    Specifies a set of default options for cvs. These options are interpreted before the startup file (~/.cvsrc) is read and can be overridden by explicit command line parameters.

CVS_RSH
    cvs uses the contents of this variable to determine the name of the remote shell command to use when starting a cvs server. If this variable is not set then is used.

CVS_SERVER
    cvs uses the contents of this variable to determine the name of the cvs server command. If this variable is not set then is used.

CVSWRAPPERS
    This variable is used by the script to determine the name of the wrapper file, in addition to the wrappers defaults contained in the repository (CVSROOT/cvswrappers) and the user's home directory (~/.cvswrappers).

AUTHORS

Dick Grune
    Original author of the cvs shell script version posted to comp.sources.unix in the volume6 release of December, 1986. Credited with much of the cvs conflict resolution algorithms.

Brian Berliner
    Coder and designer of the cvs program itself in April, 1989, based on the original work done by Dick.

Jeff Polk
    Helped Brian with the design of the cvs module and vendor branch support and author of the checkin(1) shell script (the ancestor of

And many others too numerous to mention here.

SEE ALSO
The most comprehensive manual for CVS is Version Management with CVS by Per Cederqvist et al. Depending on your system, you may be able to get it with the info cvs command or it may be available as cvs.ps (postscript), cvs.texinfo (texinfo source), or cvs.html. For CVS updates, more information on documentation, software related to CVS, development of CVS, and more, see:
http://cvs.nongnu.org
ci(1), co(1), cvs(5), cvsbug(8), diff(1), grep(1), patch(1), rcs(1), rcsdiff(1), rcsmerge(1), rlog(1).