popen.c

#include <stdio.h>
#include <stdlib.h>
int main(){
    FILE *fpipe;
    char *command="echo \"2+2.\" | erl_call -sname ggs -e";
    char line[256];

    if ( !(fpipe = (FILE*)popen(command,"r")) ){
        perror("Problems with the pipe");
        exit(1);
    }

    while ( fgets( line, sizeof line, fpipe)){
        puts(line);
    }
    
    pclose(fpipe);
}