Python C program subprocess hangs at “for line in iter”

Question

Ok so I\'m trying to run a C program from a python script. Currently I\'m using a test C program:

#include 

int main() {
while (1) {
    prin         


        

Answer 1

Your program isn't hung, it just runs very slowly. Your program is using buffered output; the "2000\n" data is not being written to stdout immediately, but will eventually make it. In your case, it might take BUFSIZ/strlen("2000\n") seconds (probably 1638 seconds) to complete.

After this line:

printf("2000\n");

add

fflush(stdout);