MULTI provides a proprietary version control system (MVC) for text files. By default, MULTI is configured to use MVC as its version control system. If you already use another version control system, see the "Other version control systems" to learn how you can use your existing version control system with MULTI. If you do not yet have a version control system, it is easy to begin using MVC.
Caution: MVC works on text files only. If you attempt to check in any binary files, they will be deleted without warning.
MULTI keeps track of all changes to your text file in a separate log file. When you edit the file, you first "check out" your file from version control. After you finish editing your file, you then "check in" your changes. This creates a new version in the log file. The log file preserves the entire version history, allowing you to restore any previous version to compare or revert back to another file.
If you are using the MULTI editor to edit a file under version control, the file is automatically checked out when you make changes, assuming you have Automatic Checkout enabled. The file is automatically checked in when you close it. During the check in process, a dialog appears, requesting comments. These comments are saved in the log file along with the new version.
To prevent changes from being made to files without the version control system's knowledge, all files in version control are read-only. Files become writable when they are checked out and return to read-only status when they are checked in. Files become writable only to the user who checked out the files. This prevents multiple users from editing the same file at the same time.
When a file is in version control, several directories are created in the same directory:
This directory contains log files. For example, if the file /a/john/fly.c is placed under version control, then the log file is /a/john/mvc.log/fly.c.
Note: These log files must not be modified by hand, as all version history may be lost if the file becomes corrupted.
This directory contains the lock files showing who has checked out the file. MVC only allows one user to check out a file at a time. The lock file for /a/john/fly.c is /a/john/mvc.log/mvc.lok/fly.c.
This directory contains temporary files used as semaphores to prevent two different MULTI sessions from writing to the same log file at the same time.