Win32 Perl Programming: The Standard Extensions, Second Edition

Process Management

The Microsoft Visual C++ documentation defines a process as “an executing instance of an application. For example, when you double-click the Notepad icon, you start a process that runs Notepad.” Processes have long been a necessity to Perl programmers, and the language reflects this by providing several commands that enable you to create processes:

• System command. system ( "program.exe" );

• Open command using piped output. open( PROGRAM , "program.exe |");

• Open command using piped input. open( PROGRAM, " | program.exe" );

• Backtricks. @Output = `program.exe`;

Each of these commands enables you to launch a program. The problem with these, however, is that the new process cannot be controlled. If you run the code in Example 8.1