View difference between Paste ID: dcpJ2fv5 and 1ZRtnT2i

 #include <stdio.h>
 #include <stdlib.h>
 #include <time.h>
 #include <error.h>
 #include <errno.h>
 
 void stopwatch(double wait_time)
 {
   time_t t1, t2;
 
   for (t1 = t2 = time(NULL); difftime(t2, t1) < wait_time; t2 = time(NULL))
     ;
 }
 
 int
 main(int argc, char **argv)
 {
   FILE *fp;
   char buf[100];
   double wait_time;
 
   if (argc != 2)
     error(EXIT_FAILURE, errno, "need filename");
 
   if ((fp = fopen(argv[1], "r")) == NULL)
     error(EXIT_FAILURE, errno, "fopen: ");
 
   while (fscanf(fp, "%lf%100s", &wait_time, buf) != EOF)
   {
     printf("%s\n", buf);
     stopwatch(wait_time);
   }
 
   if (ferror(fp))
     error(EXIT_FAILURE, errno, "ferror: ");
   return 0;
 }