executing command in Java

    try {
       // Execute a command without arguments
       String command = "ls";
       Process child = Runtime.getRuntime().exec(command);
  
       // Execute a command with an argument
       command = "ls /tmp";
       child = Runtime.getRuntime().exec(command);
   } catch (IOException e) {
   }

If an argument contain spaces, it is necessary to use the overload that requires the command and its arguments to be supplied in an array:

    try {
       // Execute a command with an argument that contains a space
       String[] commands = new String[]{"grep", "hello world", "/tmp/f.txt"};
       commands = new String[]{"grep", "hello world", "c:\\Documents and Settings\\f.txt"};
       Process child = Runtime.getRuntime().exec(commands);
   } catch (IOException e) {
   }