#include <stdio.h>int main(int argc, char **argv){	 FILE *pipein_fp, *pipeout_fp;        char readbuf[80];        /*create one way pipe line with call to popen()*/        if((pipein_fp = popen(argv[1],"r")) == NULL){                perror("popen");                exit(1);        }        if((pipeout_fp = popen(argv[3],"w")) == NULL){                perror("popen");                exit(1);        }                                                                                        while(fgets(readbuf,80,pipein_fp))                fputs(readbuf,pipeout_fp);                                                                                        pclose(pipein_fp);        pclose(pipeout_fp);        return 0;}