cvs co project_name

cvs  -q -n up -d

cvs -q up -d

cvs add filename

cvs ci -m "comment" filename

cvs diff filename 

rm filename; cvs rm filename; cvs ci -m "xx"  filename;
or
cvs rm -f filename ; cvs ci -m "xx" ffilename; 

cvs up -p filename > filename
cvs ci -m "back to previous version" filename 

cvs tag -F tag_name project_name 

cvs tag -b branch_name ./ 

cvs co -r tag_name or branch_name project_name 

cvs export -D now project_name
cvs export -r tag_name project_name 

cvs login

cvs log filename