How to send value to _popen?

Answer 1

Redirection is accomplished by the shell, not by the execution or piping mechanism. Since popen gives you a FILE* object on which you can read from the program's standard output, you should simply read from the result file and write that result to a FILE* that you construct with fopen("test.txt","w"). Also, you should be aware that the IEEE Std. 1003.1 "POSIX" function is popen, the _popen business is a MSFT thing.

Answer 2

Thanks Aaron. Yep, I'm currently on Ms Visual Studio right now. My other way is, how can I concatenate these pointers to become a full statement that can be send inside the _popen? Here is my plan :

char *cmd1 = "java -jar c:\simmetrics.jar";

char *cmd2 = "some text";

char *cmd3 = "some other text";

char *cmd4 = "> c:\test.txt";

char *final = cmd1 + cmd2 + cmd3 + cmd4; // <------ how can I achieve this?

FILE *child = _popen(final, "r"); <--- 'final' contains complete statement from above