2.3. A First Impression of Version Control with ComPact

To proceed, we suggest you apply the following patch to the message utility, making the message stand out more clearly:

• MessageUtil / src / messageutil.c:

    #include <stdio.h> void message ( char* string ) {
    printf("\n%s\n\n", string); // note additional newline
    characters }
  

  
  
  

The ensuing package may be considered a new development version of MessageUtil. It should be recorded as such by committing it to the central version control repository. Yet, an errror message will be displayed if you type the appropriate command -- pkgm -commit patch -- right away. The reason is that process management with ComPact involves a multitude of consistency checks. One of them ensures that no package state is committed to the repository without a successful build. So you must type pkgm -build prior to typing pkgm -commit patch. If everything works out, ComPact will inform you that the package in your work space is being tagged as d0_0_1. You may then re-ship it to your local pool. To import this installation into MessageUtilTest, all what needs to be done consists of modifying the corresponding import statememt:

• MessageUtilTest / PkgDesc:

    import("messageutil", "d0.0.1")
    c_source("messageutiltest")
    program("messageutiltest")
  

  
  
  

This example, though small, gives an impression of the versatility of version management with ComPact. The details can be found in Chapter 7. In particular, there is an outright development model. Its basis consists of distinguishing a main trunk and zero or more release branches.

As for some preliminary remarks concerning consistency control in connection with version management, you may also refer to Section 3.2.