There are 3 commands you need to know to use CVS:
More commands are necessary to set up a repository, but the above are all you need to get things out of and back into an existing repository.
To work with a repository you can either pass a -d /path/to/cvsroot argument to cvs(1) for every operation, or set the CVSROOT EnvironmentVariable to point to it:
export CVSROOT=/path/to/cvsroot
This is most useful when you actually work with a particular repository. Passing the -d switch is more convenient for one-off operations, such as checking someone else's project out of their repository for compiling with no intent to actually commit back any changes.
Checking stuff out of the repository is trivial. You just need to know which “module” you want to check out:
cd ~/src # where to check out the code to cvs checkout report # check out module named "report"
Note that the files are not checked out into the current directory, but into a directory named after the module. So next you'll probably want to go in there:
cd report
Now make the desired changes to the respective files. Getting the changes back into the repository is very easy:
cvs commit
You need to do this from the correct directory, because CVS needs to find the files with MetaData it created when you checked things out. These records store information such as which module in which repository things came from.
You can also commit specific files only:
cvs commit README todo.txt
If the machine does not have a repository set up, you need to decide where to store the modules. /var/lib/cvs/ might be a good place for a multiuser system:
sudo mkdir -m 775 /var/lib/cvs/ export CVSROOT=/var/lib/cvs/
Or for just yourself, use your home directory:
mkdir ~/cvs export CVSROOT=~/cvs
Or pick any other place you might prefer. Then create a skeleton repository:
cvs init
Now, you need to import a SourceCode module and store it in the repository. First, decide on a module name; this will be a directory name internally, so it should probably have no spaces. Additionally, you need a “vendor tag” to identify the owner of the files; in practice, any arbitrary name will do. You also need to pick a “release tag” which will be used as the initial version of the files being imported.
cd source/code/topdir # wherever the files and directories to import are MODULENAME="report" VENDORTAG="original upstream" RELEASETAG="initial" cvs import "$MODULENAME" "$VENDORTAG" "$RELEASETAG"
cvs(1) will launch the editor specified in your EDITOR or VISUAL EnvironmentVariable to ask for a comment. Just put initial version or something.
This will create a new directory $CSVROOT/$MODULENAME. Note that this only sets up the module. You now need to check it out of the repository before making any changes.
cvs checkout "$MODULENAME"
This particular repository allows anonymous, read-only checkout. pserver is the protocol used for that.
export CVSROOT=:pserver:cvs_anon@cvs.scms.waikato.ac.nz:/usr/local/global-cvs/gsdl-src
You would need a username and password on that particular machine and use SSH to have write access. If you do, the EnvironmentVariables will be slightly different:
export CVS_RSH=ssh export CVSROOT=:ext:username@server:/directory/to/repository
Now check out the code:
cvs checkout gsdl
Make your own changes to the source code:
dd if=/dev/random of=a_source_file.cpp bs=1k count=$RANDOM
(I swear this is how some of our 4th years come up with their code...)
Now, you can use CVS to see how your stuff differs from everyone else's, and how to get everyone else's changes into your checked out version.
$ cvs update ? HTMLPlug.pm-readme ? mht cvs server: Updating . P ConvertToPlug.pm M HTMLPlug.pm P WordPlug.pm
P means "patched"; my version was patched to be updated to other people's changes that they have committed. M means locally modified (ie by me).
You can see what is different between my version and the current checked in version:
$ cvs diff HTMLPlug.pm Index: HTMLPlug.pm =================================================================== RCS file: /usr/local/global-cvs/gsdl-src/gsdl/perllib/plugins/HTMLPlug.pm,v retrieving revision 1.58 diff -r1.58 HTMLPlug.pm 524c524 < $tmptext = s/\s\S*$/…/; --- > $tmptext = s/\s\S*$/…/; # horizontal ellipsis ... 705,707c705,707 < $$textref = s/&(lt|gt|amp|quot|nbsp);/&z$1;/go; < $$textref = s/&([^;]+);/&ghtml::getcharequiv($1,1)/gseo; < $$textref = s/&z(lt|gt|amp|quot|nbsp);/&$1;/go; --- > # $$textref = s/&(lt|gt|amp|quot|nbsp);/&z$1;/go; > $$textref = s/&([^;]+);/&ghtml::getcharequiv($1,0)/gseo; > # $$textref = s/&z(lt|gt|amp|quot|nbsp);/&$1;/go;
So this diff shows that I added a comment to line 524, and commented out lines 705 and 707 (and changed line 706). You may or may not recognise this gibberish as Perl code...
Other useful CVS commands:
$ cvs status src/gsdl/perllib/plugins$ cvs status HTMLPlug.pm =================================================================== File: HTMLPlug.pm Status: Locally Modified Working revision: 1.58 Repository revision: 1.58 /usr/local/global-cvs/gsdl-src/gsdl/perllib/plugins/HTMLPlug.pm,v Sticky Tag: (none) Sticky Date: (none) Sticky Options: (none)
$ cvs annotate
src/gsdl/perllib/plugins$ cvs annotate HTMLPlug.pm
[ trimmed for brevity ]
1.7 (sjboddie 06-Dec-99): # if no title use first 100 characters
1.7 (sjboddie 06-Dec-99): my $tmptext = $$textref;
1.43 (jrm21 21-May-01): $tmptext = s/<\/([^>]+)><\1>//g; # (eg) </b><b> - no space
1.30 (say1 14-Oct-00): $tmptext = s/<[^>]*>/ /g;
1.56 (jrm21 11-Jul-02): $tmptext = s/(?: |\xc2\xa0)/ /g; # utf-8 for nbsp...
1.43 (jrm21 21-May-01): $tmptext = s/^\s+//s;
1.16 (gwp 22-Jun-00): $tmptext = s/\s+$//;
1.14 (gwp 24-May-00): $tmptext = s/\s+/ /gs;
1.56 (jrm21 11-Jul-02): $tmptext = s/^$self->{'title_sub'}// if ($self->{'title_sub'});
1.56 (jrm21 11-Jul-02): $tmptext = s/^\s+//s; # in case title_sub introduced any...
1.30 (say1 14-Oct-00): $tmptext = substr ($tmptext, 0, 100);
1.14 (gwp 24-May-00): $tmptext = s/\s\S*$/.../;
1.15 (sjboddie 20-Jun-00): $doc_obj->add_utf8_metadata ($section, $field, $tmptext);
1.33 (paynter 02-Nov-00): print $outhandle " extracted \"$field\" metadata \"$tmptext\"\n"
1.36 (sjboddie 18-Jan-01): if ($self->{'verbosity'} > 2);
1.16 (gwp 22-Jun-00): next;
[ trimmed for brevity ]
This shows each line (as checked in) of the file, showing when that line was last edited, who by, when, and which version. So if you make a stuff-up, everyone else knows who to blame.
