/* $Id: 8bitscan.c 40 2007-10-20 09:18:22Z dleigh $
 *
 * Dylan Leigh 2007 -=- This program is in the public domain.
 *                      Hyperlinks are appreciated but not required.
 *
 *
 *    8 Bit Character Scanner
 *
 * For each file given as an argument, scan it for 8-bit characters.
 * Print matches like so:
 * <file>, line <line>: <column>, <column>, ...
 *
 * Should handle files with no terminating newline, and lines of any
 * length up to UNSIGNED_MAX.
 *
 * BUGS: Undefined behaviour may result if:
 *          - There are more than UNSIGNED_MAX lines in the file
 *          - There are more than UNSIGNED_MAX characters in a line
 *       (On most systems this equates to 4GB of newlines, or
 *       characters on a line, so this shouldn't cause problems)
 *
 */

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

int main(int argc, char** argv)
{
   unsigned fnum = 1;      // index to filename in argv
   FILE * file = NULL;     // file we are working on

   if (argc < 2) // no args, do usage and quit
   {
      fprintf(stderr, "Usage: %s file [file] [file] ...\n", argv[0]);
      exit(EXIT_FAILURE);
   }

   for (fnum = 1; fnum < argc; fnum++)
   {
      unsigned matches = 0;   // matches in current line

      file = fopen(argv[fnum],"r");
      if (NULL == file) // can't open file
      {
         perror(argv[fnum]);
      }
      else
      {
         unsigned lnum = 0;      // line number in current file
         unsigned cnum = 0;      // character count in current line
         int c;                  // char read from file (int for errors)

         while (EOF != (c = fgetc(file)))
         {
            cnum++;
            if (c > 127) // 8 bit character
            {
               if (matches)
               {
                  matches++;
                  printf(", %d", cnum);
               }
               else  // first match on this line, print file, line
               {
                  matches++;
                  printf("%s line %d: %d", argv[fnum], lnum, cnum);
               }
            }
            else // not 8 bit
            {
               if ('\n' == c)
               {
                  /* Terminate the printed line (if exists), reset
                   * matches and char count, increment line num. */

                  if (matches)
                     printf("\n");

                  matches = 0;
                  cnum = 0;
                  lnum++;
               }
            }
         } // end while read line
         if (feof(file))
         {
            // Special case: last line has no newline
            // check to see if we need to end the printf
            if (matches)
            {
               printf("\n");
            }
         }
         else // file read error
         {
            perror(argv[fnum]);
         }
      } // end else on opening file
   } //end for fnum

   return EXIT_SUCCESS;
} // end main ()