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src/Source/LibJPEG/rdjpgcom.c  view on Meta::CPAN

       */
    case M_SOF0:		/* Baseline */
    case M_SOF1:		/* Extended sequential, Huffman */
    case M_SOF2:		/* Progressive, Huffman */
    case M_SOF3:		/* Lossless, Huffman */
    case M_SOF5:		/* Differential sequential, Huffman */
    case M_SOF6:		/* Differential progressive, Huffman */
    case M_SOF7:		/* Differential lossless, Huffman */
    case M_SOF9:		/* Extended sequential, arithmetic */
    case M_SOF10:		/* Progressive, arithmetic */
    case M_SOF11:		/* Lossless, arithmetic */
    case M_SOF13:		/* Differential sequential, arithmetic */
    case M_SOF14:		/* Differential progressive, arithmetic */
    case M_SOF15:		/* Differential lossless, arithmetic */
      if (verbose)
	process_SOFn(marker);
      else
	skip_variable();
      break;

    case M_SOS:			/* stop before hitting compressed data */
      return marker;

    case M_EOI:			/* in case it's a tables-only JPEG stream */
      return marker;

    case M_COM:
      process_COM(raw);
      break;

    case M_APP12:
      /* Some digital camera makers put useful textual information into
       * APP12 markers, so we print those out too when in -verbose mode.
       */
      if (verbose) {
	printf("APP12 contains:\n");
	process_COM(raw);
      } else
	skip_variable();
      break;

    default:			/* Anything else just gets skipped */
      skip_variable();		/* we assume it has a parameter count... */
      break;
    }
  } /* end loop */
}


/* Command line parsing code */

static const char * progname;	/* program name for error messages */


static void
usage (void)
/* complain about bad command line */
{
  fprintf(stderr, "rdjpgcom displays any textual comments in a JPEG file.\n");

  fprintf(stderr, "Usage: %s [switches] [inputfile]\n", progname);

  fprintf(stderr, "Switches (names may be abbreviated):\n");
  fprintf(stderr, "  -raw        Display non-printable characters in comments (unsafe)\n");
  fprintf(stderr, "  -verbose    Also display dimensions of JPEG image\n");

  exit(EXIT_FAILURE);
}


static int
keymatch (char * arg, const char * keyword, int minchars)
/* Case-insensitive matching of (possibly abbreviated) keyword switches. */
/* keyword is the constant keyword (must be lower case already), */
/* minchars is length of minimum legal abbreviation. */
{
  register int ca, ck;
  register int nmatched = 0;

  while ((ca = *arg++) != '\0') {
    if ((ck = *keyword++) == '\0')
      return 0;			/* arg longer than keyword, no good */
    if (isupper(ca))		/* force arg to lcase (assume ck is already) */
      ca = tolower(ca);
    if (ca != ck)
      return 0;			/* no good */
    nmatched++;			/* count matched characters */
  }
  /* reached end of argument; fail if it's too short for unique abbrev */
  if (nmatched < minchars)
    return 0;
  return 1;			/* A-OK */
}


/*
 * The main program.
 */

int
main (int argc, char **argv)
{
  int argn;
  char * arg;
  int verbose = 0, raw = 0;

  /* On Mac, fetch a command line. */
#ifdef USE_CCOMMAND
  argc = ccommand(&argv);
#endif

  progname = argv[0];
  if (progname == NULL || progname[0] == 0)
    progname = "rdjpgcom";	/* in case C library doesn't provide it */

  /* Parse switches, if any */
  for (argn = 1; argn < argc; argn++) {
    arg = argv[argn];
    if (arg[0] != '-')
      break;			/* not switch, must be file name */
    arg++;			/* advance over '-' */