path: root/main.c

/*  Pdlzip - A data compressor based on the LZMA algorithm
    2009-08-14 : Igor Pavlov : Public domain
    Copyright (C) 2010 Antonio Diaz Diaz.

    This program is free software: you have unlimited permission
    to copy, distribute and modify it.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*/

#define _FILE_OFFSET_BITS 64

#include <errno.h>
#include <limits.h>
#include <signal.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "carg_parser.h"
#include "pdlzip.h"
#include "Alloc.h"
#include "7zFile.h"
#include "LzmaDec.h"
#include "LzmaEnc.h"

#if CHAR_BIT != 8
#error "Environments where CHAR_BIT != 8 are not supported."
#endif

#ifndef LLONG_MAX
#define LLONG_MAX  0x7FFFFFFFFFFFFFFFLL
#endif
#ifndef LLONG_MIN
#define LLONG_MIN  (-LLONG_MAX - 1LL)
#endif
#ifndef ULLONG_MAX
#define ULLONG_MAX 0xFFFFFFFFFFFFFFFFULL
#endif

long long int llabs( long long int number );


static void *SzAlloc(void *p, size_t size) { p = p; return MyAlloc(size); }
static void SzFree(void *p, void *address) { p = p; MyFree(address); }
static ISzAlloc g_Alloc = { SzAlloc, SzFree };

const char * invocation_name = 0;
const char * const Program_name    = "Pdlzip";
const char * const program_name    = "pdlzip";
const char * const program_year    = "2010";


struct { const char * from; const char * to; } const known_extensions[] = {
  { ".lz",   ""     },
  { ".tlz",  ".tar" },
  { ".lzma", ""     },
  { 0,       0      } };

struct Lzma_options
  {
  int dictionary_size;		/* 4KiB..512MiB */
  int match_len_limit;		/* 5..273 */
  };

enum Mode { m_compress = 0, m_decompress, m_test };
char * output_filename = 0;


/* assure at least a minimum size for buffer `buf' */
inline void * resize_buffer( void * buf, const int min_size )
  {
  if( buf ) buf = realloc( buf, min_size );
  else buf = malloc( min_size );
  return buf;
  }


static void show_help()
  {
  printf( "%s - A \"public domain\" version of the lzip data compressor\n", Program_name );
  printf( "able to decompress legacy lzma-alone (.lzma) files.\n" );
  printf( "\nUsage: %s [options] [file]\n", invocation_name );
  printf( "\nOptions:\n" );
  printf( "  -h, --help                 display this help and exit\n" );
  printf( "  -V, --version              output version information and exit\n" );
  printf( "  -c, --stdout               send output to standard output\n" );
  printf( "  -d, --decompress           decompress\n" );
/*  printf( "  -f, --force                overwrite existing output files\n" ); */
/*  printf( "  -k, --keep                 keep (don't delete) input files\n" ); */
  printf( "  -m, --match-length=<n>     set match length limit in bytes [36]\n" );
  printf( "  -q, --quiet                suppress all messages\n" );
  printf( "  -s, --dictionary-size=<n>  set dictionary size limit in bytes [8MiB]\n" );
  printf( "  -t, --test                 test compressed file integrity\n" );
  printf( "  -v, --verbose              be verbose (a 2nd -v gives more)\n" );
  printf( "  -1 .. -9                   set compression level [default 6]\n" );
  printf( "      --fast                 alias for -1\n" );
  printf( "      --best                 alias for -9\n" );
  printf( "If no file name is given, %s compresses or decompresses\n", program_name );
  printf( "from standard input to standard output.\n" );
  printf( "Numbers may be followed by a multiplier: k = kB = 10^3 = 1000,\n" );
  printf( "Ki = KiB = 2^10 = 1024, M = 10^6, Mi = 2^20, G = 10^9, Gi = 2^30, etc...\n" );
  printf( "\nReport bugs to lzip-bug@nongnu.org\n" );
/*  printf( "Pdlzip home page: http://www.nongnu.org/lzip/pdlzip.html\n" ); */
  }


static void show_version()
  {
  printf( "%s %s\n", Program_name, PROGVERSION );
  printf( "Copyright (C) %s Antonio Diaz Diaz.\n", program_year );
  printf( "Public Domain 2009 Igor Pavlov.\n" );
  printf( "This is free software: you are free to change and redistribute it.\n" );
  printf( "There is NO WARRANTY, to the extent permitted by law.\n" );
  }


static const char * format_num( long long num, long long limit,
                                const int set_prefix )
  {
  const char * const si_prefix[8] =
    { "k", "M", "G", "T", "P", "E", "Z", "Y" };
  const char * const binary_prefix[8] =
    { "Ki", "Mi", "Gi", "Ti", "Pi", "Ei", "Zi", "Yi" };
  static bool si = false;
  static char buf[16];

  if( set_prefix ) si = ( set_prefix > 0 );
  {
  const int factor = ( si ) ? 1000 : 1024;
  const char * const *prefix = ( si ) ? si_prefix : binary_prefix;
  const char *p = "";
  int i;
  limit = max( 999LL, min( 999999LL, limit ) );

  for( i = 0; i < 8 && ( llabs( num ) > limit ||
       ( llabs( num ) >= factor && num % factor == 0 ) ); ++i )
    { num /= factor; p = prefix[i]; }
  snprintf( buf, sizeof buf, "%lld %s", num, p );
  }
  return buf;
  }


static long long getnum( const char * const ptr, const int bs,
                         const long long llimit, const long long ulimit )
  {
  long long result;
  char *tail;

  errno = 0;
  result = strtoll( ptr, &tail, 0 );
  if( tail == ptr )
    {
    show_error( "Bad or missing numerical argument.", 0, true );
    exit( 1 );
    }

  if( !errno && tail[0] )
    {
    int factor = ( tail[1] == 'i' ) ? 1024 : 1000;
    int exponent = 0, i;
    bool bad_multiplier = false;
    switch( tail[0] )
      {
      case ' ': break;
      case 'b': if( bs > 0 ) { factor = bs; exponent = 1; }
                else bad_multiplier = true;
                break;
      case 'Y': exponent = 8; break;
      case 'Z': exponent = 7; break;
      case 'E': exponent = 6; break;
      case 'P': exponent = 5; break;
      case 'T': exponent = 4; break;
      case 'G': exponent = 3; break;
      case 'M': exponent = 2; break;
      case 'K': if( factor == 1024 ) exponent = 1; else bad_multiplier = true;
                break;
      case 'k': if( factor == 1000 ) exponent = 1; else bad_multiplier = true;
                break;
      default : bad_multiplier = true;
      }
    if( bad_multiplier )
      {
      show_error( "Bad multiplier in numerical argument.", 0, true );
      exit( 1 );
      }
    for( i = 0; i < exponent; ++i )
      {
      if( LLONG_MAX / factor >= llabs( result ) ) result *= factor;
      else { errno = ERANGE; break; }
      }
    }
  if( !errno && ( result < llimit || result > ulimit ) ) errno = ERANGE;
  if( errno )
    {
    show_error( "Numerical argument out of limits.", 0, false );
    exit( 1 );
    }
  return result;
  }


static int get_dict_size( const char * const arg )
  {
  char *tail;
  int bits = strtol( arg, &tail, 0 );
  if( bits >= min_dictionary_bits &&
      bits <= max_dictionary_bits && *tail == 0 )
    return ( 1 << bits );
  return getnum( arg, 0, min_dictionary_size, max_dictionary_size );
  }


static void show_name( const char * const name )
  {
  if( verbosity >= 1 )
    fprintf( stderr, "  %s: ", ( name && name[0] ) ? name : "(stdin)" );
  }


#define IN_BUF_SIZE (1 << 16)
#define OUT_BUF_SIZE (1 << 16)

static bool read_inbuf( ISeqInStream * const inStream, Byte inBuf[],
                        size_t * const inPos, size_t * const inSize )
  {
  size_t rest;
  if( *inPos >= *inSize ) *inSize = 0;
  else if( *inPos > 0 )
    {
    memmove( inBuf, inBuf + *inPos, *inSize - *inPos );
    *inSize -= *inPos;
    }
  *inPos = 0;
  rest = IN_BUF_SIZE - *inSize;
  if( rest > 0 )
    {
    if( inStream->Read( inStream, inBuf + *inSize, &rest ) != 0 )
      { show_error( "Read error", errno, false ); return false; }
    *inSize += rest;
    }
  return true;
  }


static int lzma_Decode2( UInt64 unpackSize, CLzmaDec *state,
                         ISeqOutStream *outStream, ISeqInStream *inStream,
                         Byte inBuf[], size_t * const inPos,
                         size_t * const inSize, const bool testing )
  {
  long long total_in = 13, total_out = 0;
  Byte outBuf[OUT_BUF_SIZE];
  size_t outPos = 0;
  const bool thereIsSize = (unpackSize != (UInt64)(Int64)-1);
  LzmaDec_Init(state);

  for (;;)
    {
    SizeT inProcessed;
    SizeT outProcessed = OUT_BUF_SIZE - outPos;
    ELzmaFinishMode finishMode = LZMA_FINISH_ANY;
    ELzmaStatus status;

    if( *inPos == *inSize && !read_inbuf( inStream, inBuf, inPos, inSize ) )
      return 1;
    inProcessed = *inSize - *inPos;
    if (thereIsSize && outProcessed > unpackSize)
      {
      outProcessed = (SizeT)unpackSize;
      finishMode = LZMA_FINISH_END;
      }

    if( LzmaDec_DecodeToBuf( state, outBuf + outPos, &outProcessed,
        inBuf + *inPos, &inProcessed, finishMode, &status ) != 0 )
      { show_error( "Data error.", 0, false ); return 1; }
    *inPos += inProcessed;
    total_in += inProcessed;
    outPos += outProcessed;
    unpackSize -= outProcessed;

    if (outStream)
      if (outStream->Write(outStream, outBuf, outPos) != outPos)
        { show_error( "Can not write output file", errno, false ); return 1; }

    total_out += outPos;
    outPos = 0;

    if( ( inProcessed == 0 && outProcessed == 0 ) ||
        ( thereIsSize && unpackSize == 0 ) )
      {
      if( ( thereIsSize && unpackSize != 0 ) ||
          ( !thereIsSize && status != LZMA_STATUS_FINISHED_WITH_MARK ) )
        { show_error( "Data error.", 0, false ); return 1; }
      if( verbosity >= 2 )
        fprintf( stderr, "lzma-alone, dictionary size %7sB.  ",
                 format_num( state->prop.dicSize, 9999, 0 ) );
      if( verbosity >= 3 )
        fprintf( stderr, "uncompressed size %9lld, compressed size %8lld.  ",
                 total_out, total_in );
      if( verbosity >= 1 )
        { if( testing ) fprintf( stderr, "(apparently) ok\n" );
          else fprintf( stderr, "(apparently) done\n" ); }
      return 0;
      }
    }
  }


static int Decode2( CLzmaDec *state, ISeqOutStream *outStream,
                    ISeqInStream *inStream, Byte inBuf[], size_t * const inPos,
                    size_t * const inSize, const int member_version,
                    const bool testing )
  {
  long long total_in = Fh_size, total_out = 0;
  Byte outBuf[OUT_BUF_SIZE];
  size_t outPos = 0;
  uint32_t crc = 0xFFFFFFFFU;
  LzmaDec_Init(state);

  for (;;)
    {
    SizeT inProcessed;
    SizeT outProcessed = OUT_BUF_SIZE - outPos;
    ELzmaFinishMode finishMode = LZMA_FINISH_ANY;
    ELzmaStatus status;

    if( *inPos == *inSize && !read_inbuf( inStream, inBuf, inPos, inSize ) )
      return 1;
    if( *inPos == *inSize )
      { show_error( "Unexpected EOF.", 0, false ); return 1; }
    inProcessed = *inSize - *inPos;

    if( LzmaDec_DecodeToBuf( state, outBuf + outPos, &outProcessed,
        inBuf + *inPos, &inProcessed, finishMode, &status ) != 0 )
      { show_error( "Data error.", 0, false ); return 1; }
    *inPos += inProcessed;
    total_in += inProcessed;
    outPos += outProcessed;

    if (outStream)
      if (outStream->Write(outStream, outBuf, outPos) != outPos)
        { show_error( "Can not write output file", errno, false ); return 1; }

    CRC32_update_buf( &crc, outBuf, outPos );
    total_out += outPos;
    outPos = 0;

    if (inProcessed == 0 && outProcessed == 0)
      {
      File_trailer trailer;
      size_t i;
      const size_t trailer_size = Ft_versioned_size( member_version );
      bool error = false;

      if( status != LZMA_STATUS_FINISHED_WITH_MARK )
        { show_error( "Data error.", 0, false ); return 1; }
      if( *inSize - *inPos < trailer_size &&
          !read_inbuf( inStream, inBuf, inPos, inSize ) ) return 1;
      if( *inSize - *inPos < trailer_size )
        {
        error = true;
        if( verbosity >= 0 )
          fprintf( stderr, "trailer truncated at trailer position %u;"
                   " some checks may fail.\n", (unsigned int)(*inSize - *inPos) );
        for( i = *inSize - *inPos; i < trailer_size; ++i )
          inBuf[*inPos+i] = 0;
        }
      for( i = 0; i < trailer_size; ++i )
        trailer[i] = inBuf[(*inPos)++];
      total_in += trailer_size;
      if( member_version == 0 ) Ft_set_member_size( trailer, total_in );
      if( Ft_get_data_crc( trailer ) != ( crc ^ 0xFFFFFFFFU ) )
        {
        error = true;
        if( verbosity >= 0 )
          fprintf( stderr, "crc mismatch; trailer says %08X, data crc is %08X.\n",
                   (unsigned int)Ft_get_data_crc( trailer ),
                   (unsigned int)( crc ^ 0xFFFFFFFFU ) );
        }
      if( Ft_get_data_size( trailer ) != total_out )
        {
        error = true;
        if( verbosity >= 0 )
          fprintf( stderr, "data size mismatch; trailer says %lld, data size is %lld.\n",
                   Ft_get_data_size( trailer ), total_out );
        }
      if( Ft_get_member_size( trailer ) != total_in )
        {
        error = true;
        if( verbosity >= 0 )
          fprintf( stderr, "member size mismatch; trailer says %lld, member size is %lld.\n",
                   Ft_get_member_size( trailer ), total_in );
        }
      if( !error && verbosity >= 3 )
        fprintf( stderr, "data crc %08X, data size %9lld, member size %8lld.  ",
                 (unsigned int)Ft_get_data_crc( trailer ),
                 Ft_get_data_size( trailer ), Ft_get_member_size( trailer ) );
      if( !error && verbosity >= 1 )
        { if( testing ) fprintf( stderr, "ok\n" );
          else fprintf( stderr, "done\n" ); }
      if( error ) return 2;
      return 0;
      }
    }
  }


static int Decode( ISeqOutStream *outStream, ISeqInStream *inStream,
                   const char * const name, const bool testing )
  {
  UInt64 unpackSize = 0;
  CLzmaDec state;
  File_header header;
  Byte inBuf[IN_BUF_SIZE];
  size_t inPos = 0, inSize = 0;
  int retval = 0;
  bool lzma_mode = false;
  bool first_member;
  /* 5 bytes of LZMA properties and 8 bytes of uncompressed size */
  unsigned char props[LZMA_PROPS_SIZE+8];

  for( first_member = true; ; first_member = false )
    {
    int i;
    if( inSize < Fh_size &&
        !read_inbuf( inStream, inBuf, &inPos, &inSize ) ) return 1;
    if( inSize < Fh_size )		/* End Of File */
      {
      if( !first_member ) break;
      show_error( "Error reading member header.", 0, false ); return 1;
      }
    for( i = 0; i < Fh_size; ++i )
      props[i] = header[i] = inBuf[inPos++];
    if( !Fh_verify_magic( header ) )
      {
      if( !first_member ) break;		/* trailing garbage */
      if( inSize >= 13 - Fh_size )		/* try lzma-alone */
        {
        for( i = Fh_size; i < 13; ++i ) props[i] = inBuf[inPos++];
        for( i = 0; i < 8; ++i )
          unpackSize += (UInt64)props[LZMA_PROPS_SIZE+i] << (i * 8);
        if( ( props[12] == 0 || props[12] == 0xFF ) && props[12] == props[11] )
          lzma_mode = true;
        }
      if( !lzma_mode )
        {
        show_error( "Bad magic number (file not in lzip format).", 0, false );
        return 2;
        }
      }
    if( !first_member ) show_name( name );
    if( !lzma_mode )
      {
      int ds, i;
      if( !Fh_verify_version( header ) )
        {
        if( verbosity >= 0 )
          fprintf( stderr, "version %d member format not supported, newer %s needed.\n",
                   Fh_version( header ), program_name );
        return 2;
        }
      if( Fh_get_dictionary_size( header ) < min_dictionary_size ||
          Fh_get_dictionary_size( header ) > max_dictionary_size )
        {
        if( verbosity >= 0 )
          fprintf( stderr, "invalid dictionary size in member header.\n" );
        return 2;
        }

      if( verbosity >= 2 )
        fprintf( stderr, "version %d, dictionary size %7sB.  ",
                 Fh_version( header ),
                 format_num( Fh_get_dictionary_size( header ), 9999, 0 ) );

      props[0] = 93;			/* (45 * 2) + (9 * 0) + 3 */
      ds = Fh_get_dictionary_size( header );
      for( i = 1; i <= 4; ++i ) { props[i] = ds & 0xFF; ds >>= 8; }
      }

    LzmaDec_Construct(&state);
    if( LzmaDec_Allocate( &state, props, LZMA_PROPS_SIZE, &g_Alloc ) != 0 )
      { show_error( "Can not allocate memory.", 0, false ); return 1; }
    if( !lzma_mode )
      retval = Decode2( &state, outStream, inStream, inBuf, &inPos,
                        &inSize, Fh_version( header ), testing );
    else
      retval = lzma_Decode2( unpackSize, &state, outStream, inStream,
                             inBuf, &inPos, &inSize, testing );
    LzmaDec_Free(&state, &g_Alloc);
    if( retval != 0 || lzma_mode ) break;
    }
  return retval;
  }


static int Encode( ISeqOutStream *outStream, ISeqInStream *inStream,
                   const struct Lzma_options * const encoder_options )
  {
  CLzmaEncProps props;
  int retval = 0;
  File_header header;

  CLzmaEncHandle enc = LzmaEnc_Create(&g_Alloc);
  if(enc == 0)
    { show_error( "Can not allocate memory.", 0, false ); return 1; }

  LzmaEncProps_Init(&props);
  props.dictSize = encoder_options->dictionary_size;
  props.lc = literal_context_bits;
  props.lp = 0;
  props.pb = pos_state_bits;
  props.fb = encoder_options->match_len_limit;
  props.btMode = 1;
  props.numHashBytes = 4;
  props.mc = 16 + ( encoder_options->match_len_limit / 2 );
  LzmaEnc_SetProps(enc, &props);

  Fh_set_magic( header );
  if( !Fh_set_dictionary_size( header, encoder_options->dictionary_size ) ||
      encoder_options->match_len_limit < min_match_len_limit ||
      encoder_options->match_len_limit > max_match_len )
    internal_error( "invalid argument to encoder" );

  if( outStream->Write( outStream, header, Fh_size ) != Fh_size )
    { show_error( "Can not write output file", errno, false ); retval = 1; }
  else
    if( LzmaEnc_Encode(enc, outStream, inStream, NULL, &g_Alloc, &g_Alloc) != 0 )
      { show_error( "Data error.", 0, false ); retval = 1; }
  LzmaEnc_Destroy(enc, &g_Alloc, &g_Alloc);
  return retval;
  }


int verbosity = 0;


void show_error( const char * const msg, const int errcode, const bool help )
  {
  if( verbosity >= 0 )
    {
    if( msg && msg[0] )
      {
      fprintf( stderr, "%s: %s", program_name, msg );
      if( errcode > 0 ) fprintf( stderr, ": %s", strerror( errcode ) );
      fprintf( stderr, "\n" );
      }
    if( help && invocation_name && invocation_name[0] )
      fprintf( stderr, "Try `%s --help' for more information.\n", invocation_name );
    }
  }


void internal_error( const char * const msg )
  {
  fprintf( stderr, "%s: internal error: %s.\n", program_name, msg );
  exit( 3 );
  }


static int extension_index( const char * const name )
  {
  int i;
  for( i = 0; known_extensions[i].from; ++i )
    {
    const char * const ext = known_extensions[i].from;
    if( strlen( name ) > strlen( ext ) &&
        strncmp( name + strlen( name ) - strlen( ext ), ext, strlen( ext ) ) == 0 )
      return i;
    }
  return -1;
  }


static void set_c_outname( const char * const name )
  {
  output_filename = resize_buffer( output_filename, strlen( name ) +
                                   strlen( known_extensions[0].from ) + 1 );
  strcpy( output_filename, name );
  strcat( output_filename, known_extensions[0].from );
  }


static void set_d_outname( const char * const name )
  {
  const int i = extension_index( name );
  if( i >= 0 )
    {
    const char * const from = known_extensions[i].from;
    if( strlen( name ) > strlen( from ) )
      {
      output_filename = resize_buffer( output_filename, strlen( name ) +
                                       strlen( known_extensions[0].to ) + 1 );
      strcpy( output_filename, name );
      strcpy( output_filename + strlen( name ) - strlen( from ),
              known_extensions[i].to );
      return;
      }
    }
  output_filename = resize_buffer( output_filename, strlen( name ) + 4 + 1 );
  strcpy( output_filename, name );
  strcat( output_filename, ".out" );
  if( verbosity >= 0 )
    fprintf( stderr, "%s: can't guess original name for `%s' -- using `%s'.\n",
             program_name, name, output_filename );
  }


CRC32 crc32;


int main( const int argc, const char * const argv[] )
  {
  /* Mapping from gzip/bzip2 style 1..9 compression modes
     to the corresponding LZMA compression modes. */
  const struct Lzma_options option_mapping[] =
    {
    { 1 << 16,   5 },		/* -0 */
    { 1 << 20,   5 },		/* -1 */
    { 3 << 19,   6 },		/* -2 */
    { 1 << 21,   8 },		/* -3 */
    { 3 << 20,  12 },		/* -4 */
    { 1 << 22,  20 },		/* -5 */
    { 1 << 23,  36 },		/* -6 */
    { 1 << 24,  68 },		/* -7 */
    { 3 << 23, 132 },		/* -8 */
    { 1 << 25, 273 } };		/* -9 */
  struct Lzma_options encoder_options = option_mapping[6];  /* default = "-6" */
  enum Mode program_mode = m_compress;
  const char * input_filename = "";
  CFileSeqInStream inStream;
  CFileOutStream outStream;
  int argind;
  int retval;
  bool force = false;
  bool keep_input_files = false;
  bool to_stdout = false;

  const struct ap_Option options[] =
    {
    { '0',  0,                ap_no  },
    { '1', "fast",            ap_no  },
    { '2',  0,                ap_no  },
    { '3',  0,                ap_no  },
    { '4',  0,                ap_no  },
    { '5',  0,                ap_no  },
    { '6',  0,                ap_no  },
    { '7',  0,                ap_no  },
    { '8',  0,                ap_no  },
    { '9', "best",            ap_no  },
    { 'b', "member-size",     ap_yes },
    { 'c', "stdout",          ap_no  },
    { 'd', "decompress",      ap_no  },
    { 'e', "extreme",         ap_no  },
    { 'f', "force",           ap_no  },
    { 'h', "help",            ap_no  },
    { 'k', "keep",            ap_no  },
    { 'm', "match-length",    ap_yes },
    { 'q', "quiet",           ap_no  },
    { 's', "dictionary-size", ap_yes },
    { 'S', "volume-size",     ap_yes },
    { 't', "test",            ap_no  },
    { 'v', "verbose",         ap_no  },
    { 'V', "version",         ap_no  },
    {  0 ,  0,                ap_no  } };

  struct Arg_parser parser;

  invocation_name = argv[0];
  CRC32_init();
  if (sizeof(UInt32) != 4 || sizeof(UInt64) != 8)
    internal_error( "incorrect UInt32 or UInt64" );

  if( !ap_init( &parser, argc, argv, options, 0 ) )
    { show_error( "Memory exhausted.", 0, false ); return 1; }
  if( ap_error( &parser ) )				/* bad option */
    { show_error( ap_error( &parser ), 0, true ); return 1; }

  for( argind = 0; argind < ap_arguments( &parser ); ++argind )
    {
    const int code = ap_code( &parser, argind );
    const char * const arg = ap_argument( &parser, argind );
    if( !code ) break;					/* no more options */
    switch( code )
      {
      case '0': case '1': case '2': case '3': case '4':
      case '5': case '6': case '7': case '8': case '9':
                encoder_options = option_mapping[code-'0']; break;
      case 'b': break;
      case 'c': to_stdout = true; break;
      case 'd': program_mode = m_decompress; break;
      case 'e': break;
      case 'f': force = true; break;
      case 'h': show_help(); return 0;
      case 'k': keep_input_files = true; break;
      case 'm': encoder_options.match_len_limit =
                getnum( arg, 0, min_match_len_limit, max_match_len ); break;
      case 'q': verbosity = -1; break;
      case 's': encoder_options.dictionary_size = get_dict_size( arg );
                break;
      case 'S': break;
      case 't': program_mode = m_test; break;
      case 'v': if( verbosity < 4 ) ++verbosity; break;
      case 'V': show_version(); return 0;
      default : internal_error( "uncaught option" );
      }
    }

  if( ap_arguments( &parser ) > argind &&
      strcmp( ap_argument( &parser, argind ), "-" ) )
    input_filename = ap_argument( &parser, argind );
  if( ap_arguments( &parser ) > argind + 1 )
    { show_error( "Too many file names.", 0, true ); return 1; }

  if( program_mode == m_test ) output_filename = "/dev/null";
  else
    {
    if( to_stdout || !input_filename[0] ) output_filename = "";
    else
      {
      if( program_mode == m_compress ) set_c_outname( input_filename );
      else set_d_outname( input_filename );
      }
    }

  FileSeqInStream_CreateVTable(&inStream);
  File_Construct(&inStream.file);

  FileOutStream_CreateVTable(&outStream);
  File_Construct(&outStream.file);

  if (InFile_Open(&inStream.file, input_filename) != 0)
    { show_error( "Can not open input file", errno, false ); return 1; }

  if (OutFile_Open(&outStream.file, output_filename) != 0)
    { show_error( "Can not open output file", errno, false ); return 1; }

  show_name( input_filename );
  if( program_mode == m_compress )
    retval = Encode( &outStream.s, &inStream.s, &encoder_options );
  else
    retval = Decode( &outStream.s, &inStream.s, input_filename, program_mode == m_test );

  File_Close(&outStream.file);
  File_Close(&inStream.file);

  ap_free( &parser );
  return retval;
  }