Listing 3:

#include <stdio.h>
#include <stdio.h>

main(int argc, char *argv[])
   {
   copy_it(argv[1], argv[2]);
   end_it("copy is done\n");
   }
copy_it(char FileIn[55], char FileOut[55])
   {
   FILE *fi;
   FILE *fo;
   int gc;
     
   /* The next 2 lines fixed the problem */  
   /* NOT VERY ELEGANT BUT IT WORKS! */
   if (*FileIn == *FileOut)
       end_it("ABORT: Make first letters of names different\n");

   if ((fi = fopen(FileIn, "rb")) == NULL) 
       end_it("File not found\n");
   if ((fo = fopen(FileOut, "wb")) == NULL)
       {
       fclose(fi);
       end_it("No output\n");
       }
   while (!feof(fi))
       {
       gc = getc(fi);                  
       if (!feof(fi)) 
           putc(gc, fo); 
       }                                 
       fclose(fi);                       
       fclose(fo);                       
   }

/*
   IF FILEIN = FILEOUT, AND FILE IS LARGER THAN ABOUT 2-3K,  


                           6



      YOU WILL DAMAGE DIRECTORY TABLE!         
*/

static end_it(s)
char *s;            /* String to display to User */
   {
   /* Display string passed and simply abort */
   fprintf(stdout, s); 
   exit (0);
   }