spawn - Unable to make executable that properly communicates with node.js -

i'm testing communication between node.js , executables launched child processes. executable launched within node.js via child_process.spawn() , output monitored node.js. i'm testing capability both on linux , windows oss.

i've spawned tail -f /var/log/syslog , listened output, own executables can't seem write correctly stdout (in whatever form exists when captured node.js).

test code:

#include <iostream> #include <stdio.h> #include <unistd.h>  int main() {     using namespace std;      long x = 1;      while (true)     {          fprintf(stdout, "xtime - %ld\n", x++);         usleep(1000000);     } } 

(note: includes may useless; i've not checked them)

stdout output not automatically flushed (at least on *nix) when stdout not tty (even if there newline in output, otherwise newline flushes when stdout tty).

so can either disable stdout buffering entirely via setbuf(stdout, null); or can manually flush output via fflush(stdout);.