#include <stdio.h>
#include <string.h>
#include <unistd.h>

main(int argc, char *argv[])
{

  char buf[1024];
  char lbuf[1024];
  char *p;
  int len;

  strcpy(buf,"/proc/");
  strcat(buf,argv[1]);
  strcat(buf,"/fd/0");
  len =readlink(buf,lbuf,1024);
  lbuf[len] = '\0';

  printf("%s\n",lbuf+4);
}