Question

I’m using popen to open a write pipe and send commands to an application. The problem is that the commands are only sent to the application when I close the pipe.

FILE * fp = open(target_app, "w");
fwrite(command, 1, command.size(), fp);
getchar(); //wait for a key, because I don't want to terminate the application
pclose(fp); // at this point, the command is sent

What could be possible wrong?

Answer 1

I just figure it out that I have to flush the pipe to send commands without the need to close it. My fix was:

FILE * fp = open(target_app, "w");
fwrite(command, 1, command.size(), fp);
fflush(fp);
getchar(); //wait for a key, because I don't want to terminate the application
pclose(fp); // at this point, the command is sent