Starting Other Programs (KDE3 Architecture)

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In KDE there are several ways to start other programs from within your application. Here is a short summary of your options with reasons why you should or should not use them.

fork + exec
You never want to use this unless you have a very good reason why it is impossible to use KProcess.
You want to use KProcess class if you need to start a new process which needs to be a child of your process, e.g. because you want to catch stdout/stderr or need to send it data via stdin. You should never use this to start other KDE applications unless your application is called kgdb :-) If you need to send/receive text like data to/from the process, you are probably better off with KProcIO.
Like KProcess. Unlike KProcess, the KProcIO class actually makes it easy to send data to and receive data from the process.
Preferred way to launch desktop (KDE/Gnome/X) applications or KDE services. The application/service must have a .desktop file. It will make use of KDEinit for increased startup performance and lower memory usage. These benefits only apply to applications available as KDEinit loadable module (KLM).
Generic way to open documents/applications/shell commands. Uses startServiceBy.... where applicable. Offers the additional benefit of startup-notification.
KRun can start any application, from the binary or the desktop file, it will determine the mimetype of a file before running the preferred handler for it, and it can also start shell commands. This makes KRun the recommended way to run another program in KDE.

Initial Author: Waldo Bastian