Programming

Building a Jar File

After you have created your ZIP and CAB archives, you can then create a JAR (Java ARchive) file that will contain your compressed and archived Applet for use with users who have the most recent versions of Netscape Navigator and HotJava.

Building JAR files is very similar to building TAR files, something with which most UNIX developers are already familiar. Unfortunately, though, as with CABARC, there is only a command line interface, so you need to build your JAR files in the DOS shell using the JAR program provided with the JDK1.1.

Today in Buit-in Funtions we will look at some HTTP functions.

header()
The header() function outputs an HTTP header string, such as a location redirection. This output must occur before any other data is sent to the browser, including HTML tags. For example to use the header() function to redirect a user to a new location, use this code:

header(“Location: http://www.techsoftcenter.com”);
exit;
(TIP – Follow a header() statement with the exit command. This ensures that the code does not continue to execute.)

Building a Cab File

After you have created your ZIP archive, you can then create a CAB (CABinet) file that will contain your compressed and archived applet for Microsoft’s Internet Explorer users. Building CAB files is a little less user-friendly than building ZIP files, since there is no graphical interface like WinZip for creating CAB files.

Instead, you will have to use the command line interface provided by CABARC. CABARC is a compression/archiving program distributed with Microsoft’s SDK located in either the “bin” directory under your main SDK directory or the “bin/packsign” directory.

Welcome back to Built-in Functions.

Filesytem Functions
chmod(), chgrp(), chown()
Like the shell commands of the same name, the chmod(), chgrp(), and chown() functions modify the permissions, grop and owner of a directory or file. Here is the syntax of these functions:

chmod(“filename”, mode);
chmgrp(“filename”, newsgroup);
chown(“filename”, newowner);
In order to change permissions, groups, or owners, the PHP user must be the owner of the file, or the permissions must already be set to allow such change by that user.

Building a Zip Archive

The first archive you will want to build is the ZIP archive, the oldest and most supported of the three. For this reason, it should be easy for you to find a ZIP archive generation program for whichever platform you are using. When choosing a ZIP utility program, however, you should be careful to choose one that supports non-8.3 filenames, since Java class files usually have names which are longer.