CVS vs. Perforce

SUMMARY

A comparison of features, terminology, and commands in Perforce and CVS.

DETAILS

This comparison is for the experienced CVS user who is new to Perforce. The following comparisons are high-level and intended to help you take advantage of your CVS knowledge to learn Perforce.

Features

The following table lists some general observations about CVS functionality compared to Perforce:

In CVS	In Perforce
You perform a checkout to create or update a working directory. The working directory contains copies of the source files specified by modules.	You perform a sync to update your client workspace according to the client workspace mapping you are using.
By default, you make changes and then tell CVS about them (unless "watch" is turned on - then you must first open a file(s) for edit before changing it).	You open a file(s) (add, edit, delete, integrate, etc.), make the change(s) and then submit the changes.
Changes can be submitted for multiple files at once, but CVS does not ensure or track that they were submitted together.	Changes are grouped into changelists - an atomic change transaction for a set of changes all submitted together (along with a user derived description of the changes made).
"modules" and/or operating system wildcards are used for aggregate file operations.	filespecs (file specifications) are used for aggregate operations.
CVS ignores file permissions and ownerships when storing files in the repository.	File attributes can be set and tracked in the metadata on the server machine.
You lock files using admin -l.	You lock files using the lock command or the +l option on the add / edit & reopen commands (sets the exclusive open attribute).
You can mark important file revisions with tags.	You can mark/tag important file revisions with labels.
You control access to the repository by changing permissions on directories in the CVSROOT path (users need write permission to check out files).	You control access by assigning permissions ( protect ) to users for all or part of the depot(s).
You can configure multiple repositories and access them with the global -d option.	You can set up multiple repositories (depots) for a server. Users use a client view specification to map the different depots or parts of depots into their workspace (users can have multiple client views). This can also include access to (read only) remote depots on other perforce servers.
Supports text file type. Binary files are stored by turning off line ending conversion and keyword expansion.	Supports six base file types: text files, binary files, unicode files, native apple files on the Macintosh, Mac resource forks, and UNIX symlinks. File type modifiers are then applied to the base types allowing for support of RCS keyword expansion, file compression on the server, and more. Perforce attempts to detect the file type and set it accordingly (which can be overridden). By default, binary files are stored compressed.

Terms

The following table compares CVS terms to their Perforce equivalents.

CVS term	Perforce term
branch	codeline
merge files/branches	integrate
mode	file type
repository	depot
reserved checkout	lock or exclusive-open
tag	label/tag
work tree	client workspace

Commands

The following table lists CVS commands and their closest Perforce equivalents.

CVS command	Perforce command(s)	Description	Remarks
add	add	CVS: Schedule the file for addition to the repository. Perforce: Opens files within the client workspace for addition to the depot. The specified file(s) are linked to a changelist.	To place the files into the source repository /depot: CVS: commit Perforce: submit (the changelist is sent to the server)
admin -k[subst]	add/edit/reopen -t [type] +k	Set RCS keyword substitution.	Perforce: The file type modifier +k is applied to the base types to allow for support of RCS keyword expansion.
admin -kb or add -kb	add/edit/reopen -t binary	Set file type to binary.	CVS: Defaults to text type, -kb turns off line ending conversion and keyword expansion. Perforce: Attempts to determine the file's type when a file is opened with add - this can be overridden with the -t option or the typemap command. Binary files are stored compressed.
admin -l[rev]	lock or add/edit/reopen -t [type] +l	Lock a file revision.	CVS: Called a "reserve checkout" (where only one user can be editing a given file at a time). Perforce: lock allows anyone to open the file for edit, but only the person who locked the file may submit it. By contrast, a file with attribute +l allows only one person to open the file for edit (exclusive open).
annotate	annotate	Show last revision where each line was modified.	Perforce: With the -a option, all lines, including deleted lines and lines no longer present at the head revision, are included and each line includes a starting and ending revision.
checkout	sync & edit	Obtain copy of source and open file for edit.	CVS: Unless watch is on, files can be changed once they are checked out. Perforce: sync populates the client workspace. Use edit to open file(s) for edit.
checkout/update -j	integrate & resolve	Merge changes from the revision specified.
checkout/update -P	client & sync	Prune empty directories.	Perforce: set the "rmdir" option in the client specification and empty directories are removed ("pruned") during a sync.
commit	submit	Check files into the repository.	CVS: Changes can be submitted for multiple files but CVS does not ensure or track that they were submitted together. Perforce: Changes are grouped into changelists - an atomic change transaction for a set of files all submitted together.
diff	diff	Show differences between revisions.	CVS: The default action is to compare your working files with the revisions they were based on. Perforce: Compares files in the client workspace to revisions in the depot.
rdiff	diff2	Show differences between releases.	CVS: diff files between two releases, operates directly from the repository. Perforce: Compares two file revisions from the depot.
diff/rdiff -c	diff/diff2 -du	Produce a "context diff" for use with the patch(1) utility.
edit	edit	Tell the system you are modifying a file.	CVS: Used when "watch" is on. Perforce: When a file is opened for edit, it is associated with a changelist for submission of the changes.
editors	changes -s pending	CVS: See who is editing a file. Perforce: List pending changelists.	CVS: Only useful if "watch" is on. Perforce: Use describe to view more information about a changelist.
export	N/A	Create a copy of the source without the CVS admin files.	Perforce: Sync can be used but requires the use of a client workspace. Also, there are no admin files in the client workspace (all the admin information is tracked on the server side in the metadata database).
history	p4d -v server=[level]	Show command history.	CVS: Only valid if history logging is turned on. Tracks each use of the checkout, commit, rtag, update, and release commands. Perforce: Turns on command tracing in the server (level 1 logs server commands), which is logged into the server log.
import	add, integ(rate)	Incorporate or update an entire source distribution from an outside source (for example, a source vendor) into your source repository directory.	Perforce: See KB Article #15 Creating a Vendor Branch for Third-party Source Code
init	depot	Set up a new repository (depot).
log	files, filelog, where	Display log information for files.
login, logout, pserver	passwd, [command] -P [password]	Set up authentication.	Perforce: By default, user records are created without passwords. A user can use the passwd command to set the password, and then provide the password to commands using the -P option or by setting the P4PASSWD environment variable.
release	sync [file(s)]#none	Remove working copy.	CVS: the release command only works on an entire directory (module). Perforce: You can sync to "#none" for a file or set of files.
remove	delete	Remove a file from the repository (depot).	Leaves the previous revisions intact. To apply the changes in the repository/depot: CVS: commit Perforce: submit
rtag, tag	label & labelsync -a	Tag files with a label.
rtag/tag -b	integrate	Create a branch.
status	files, fstat	Display information about workspace files.	Perforce:Other commands that show information about workspace files: sync -n, opened, have, and resolved.
unedit	revert	Undo an edit.	CVS: Only useful if "watch" is on. Perforce: Note: the revert command does not display a warning before discarding edits!
update	sync	Bring the workspace in sync with the repository.
update -j	integrate & resolve	Merge changes from a branch.
watch add	user, reviews & the Review daemons	Tell the SCM system to notify you when the file is changed.	CVS: notification may be provided when a file is opened for edit, unedit(ed), or commited. Perforce: Notification is provided when the files are checked in.
watchers	reviews	See who wants to be notified about changes to a file.