The use of fork and exec exemplifies the spirit of UNIX in that it provides a very simple way to start new processes. The fork call basically makes a duplicate of the current process, identical in almost every way. Not everything is copied over (for example, resource limits in some implementations) but the idea is … Read more
See if this works (sorry can’t test it right now) Runtime.getRuntime().exec(new String[]{“php”,”/var/www/script.php”, “-m”, “2”});
From the documentation: In order to execute a command and have it not hang your PHP script while it runs, the program you run must not output back to PHP. To do this, redirect both stdout and stderr to /dev/null, then background it. > /dev/null 2>&1 & In order to execute a command and have … Read more
system The system method calls a system program. You have to provide the command as a string argument to this method. For example: >> system(“date”) Wed Sep 4 22:03:44 CEST 2013 => true The invoked program will use the current STDIN, STDOUT and STDERR objects of your Ruby program. In fact, the actual return value … Read more
I found this in forums.oracle.com Allows the reuse of a process to execute multiple commands in Windows: http://kr.forums.oracle.com/forums/thread.jspa?messageID=9250051 You need something like String[] command = { “cmd”, }; Process p = Runtime.getRuntime().exec(command); new Thread(new SyncPipe(p.getErrorStream(), System.err)).start(); new Thread(new SyncPipe(p.getInputStream(), System.out)).start(); PrintWriter stdin = new PrintWriter(p.getOutputStream()); stdin.println(“dir c:\\ /A /Q”); // write any other commands you … Read more
They have slightly different purposes. exec() is for calling a system command, and perhaps dealing with the output yourself. system() is for executing a system command and immediately displaying the output – presumably text. passthru() is for executing a system command which you wish the raw return from – presumably something binary. Regardless, I suggest … Read more
There is a big difference between exec in Python 2 and exec() in Python 3. You are treating exec as a function, but it really is a statement in Python 2. Because of this difference, you cannot change local variables in function scope in Python 3 using exec, even though it was possible in Python … Read more
Write a script, and execute the script instead of separate commands. Pipe is a part of the shell, so you can also do something like this: String[] cmd = { “/bin/sh”, “-c”, “ls /etc | grep release” }; Process p = Runtime.getRuntime().exec(cmd);
This issue is somewhat discussed in the Python3 bug list. Ultimately, to get this behavior, you need to do: def foo(): ldict = {} exec(“a=3”,globals(),ldict) a = ldict[‘a’] print(a) And if you check the Python3 documentation on exec, you’ll see the following note: The default locals act as described for function locals() below: modifications to … Read more
The short answer, or TL;DR Basically, eval is used to evaluate a single dynamically generated Python expression, and exec is used to execute dynamically generated Python code only for its side effects. eval and exec have these two differences: eval accepts only a single expression, exec can take a code block that has Python statements: … Read more