JPEGView/Independent JPEG Group/djpeg.c

/*
 * djpeg.c
 *
 * Copyright (C) 1991-1994, Thomas G. Lane.
 * This file is part of the Independent JPEG Group's software.
 * For conditions of distribution and use, see the accompanying README file.
 *
 * This file contains a command-line user interface for the JPEG decompressor.
 * It should work on any system with Unix- or MS-DOS-style command lines.
 *
 * Two different command line styles are permitted, depending on the
 * compile-time switch TWO_FILE_COMMANDLINE:
 *	djpeg [options]  inputfile outputfile
 *	djpeg [options]  [inputfile]
 * In the second style, output is always to standard output, which you'd
 * normally redirect to a file or pipe to some other program.  Input is
 * either from a named file or from standard input (typically redirected).
 * The second style is convenient on Unix but is unhelpful on systems that
 * don't support pipes.  Also, you MUST use the first style if your system
 * doesn't do binary I/O to stdin/stdout.
 * To simplify script writing, the "-outfile" switch is provided.  The syntax
 *	djpeg [options]  -outfile outputfile  inputfile
 * works regardless of which command line style is used.
 */

#include "cdjpeg.h"		/* Common decls for cjpeg/djpeg applications */
#define JMAKE_MSG_TABLE
#include "cderror.h"		/* create message string table */
#include "jversion.h"		/* for version message */

#include <ctype.h>		/* to declare isupper(), tolower() */
#ifdef NEED_SIGNAL_CATCHER
#include <signal.h>		/* to declare signal() */
#endif
#ifdef USE_SETMODE
#include <fcntl.h>		/* to declare setmode() */
#endif

#ifdef THINK_C
#include <console.h>		/* command-line reader for Macintosh */
#endif

#ifdef DONT_USE_B_MODE		/* define mode parameters for fopen() */
#define READ_BINARY	"r"
#define WRITE_BINARY	"w"
#else
#define READ_BINARY	"rb"
#define WRITE_BINARY	"wb"
#endif

#ifndef EXIT_FAILURE		/* define exit() codes if not provided */
#define EXIT_FAILURE  1
#endif
#ifndef EXIT_SUCCESS
#ifdef VMS
#define EXIT_SUCCESS  1		/* VMS is very nonstandard */
#else
#define EXIT_SUCCESS  0
#endif
#endif
#ifndef EXIT_WARNING
#ifdef VMS
#define EXIT_WARNING  1		/* VMS is very nonstandard */
#else
#define EXIT_WARNING  2
#endif
#endif


/*
 * This list defines the known output image formats
 * (not all of which need be supported by a given version).
 * You can change the default output format by defining DEFAULT_FMT;
 * indeed, you had better do so if you undefine PPM_SUPPORTED.
 */

typedef enum {
	FMT_GIF,		/* GIF format */
	FMT_PPM,		/* PPM/PGM (PBMPLUS formats) */
	FMT_RLE,		/* RLE format */
	FMT_TARGA,		/* Targa format */
	FMT_TIFF		/* TIFF format */
} IMAGE_FORMATS;

#ifndef DEFAULT_FMT		/* so can override from CFLAGS in Makefile */
#define DEFAULT_FMT	FMT_PPM
#endif

static IMAGE_FORMATS requested_fmt;


/*
 * Signal catcher to ensure that temporary files are removed before aborting.
 * NB: for Amiga Manx C this is actually a global routine named _abort();
 * we put "#define signal_catcher _abort" in jconfig.h.  Talk about bogus...
 */

#ifdef NEED_SIGNAL_CATCHER

static j_common_ptr sig_cinfo;

GLOBAL void
signal_catcher (int signum)
{
  if (sig_cinfo != NULL) {
    if (sig_cinfo->err != NULL) /* turn off trace output */
      sig_cinfo->err->trace_level = 0;
    jpeg_destroy(sig_cinfo);	/* clean up memory allocation & temp files */
  }
  exit(EXIT_FAILURE);
}

#endif


/*
 * Argument-parsing code.
 * The switch parser is designed to be useful with DOS-style command line
 * syntax, ie, intermixed switches and file names, where only the switches
 * to the left of a given file name affect processing of that file.
 * The main program in this file doesn't actually use this capability...
 */


static char * progname;		/* program name for error messages */
static char * outfilename;	/* for -outfile switch */


LOCAL void
usage (void)
/* complain about bad command line */
{
  fprintf(stderr, "usage: %s [switches] ", progname);
#ifdef TWO_FILE_COMMANDLINE
  fprintf(stderr, "inputfile outputfile\n");
#else
  fprintf(stderr, "[inputfile]\n");
#endif

  fprintf(stderr, "Switches (names may be abbreviated):\n");