/* Plzip - Massively parallel implementation of lzip
   Copyright (C) 2009 Laszlo Ersek.
   Copyright (C) 2009-2021 Antonio Diaz Diaz.

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 2 of the License, or
   (at your option) any later version.

   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.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/
/*
   Exit status: 0 for a normal exit, 1 for environmental problems
   (file not found, invalid flags, I/O errors, etc), 2 to indicate a
   corrupt or invalid input file, 3 for an internal consistency error
   (eg, bug) which caused plzip to panic.
*/

#define _FILE_OFFSET_BITS 64

#include <algorithm>
#include <cerrno>
#include <climits>
#include <csignal>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <string>
#include <vector>
#include <fcntl.h>
#include <stdint.h>
#include <unistd.h>
#include <utime.h>
#include <sys/stat.h>
#include <lzlib.h>
#if defined(__MSVCRT__) || defined(__OS2__)
#include <io.h>
#if defined(__MSVCRT__)
#define fchmod(x,y) 0
#define fchown(x,y,z) 0
#define strtoull std::strtoul
#define SIGHUP SIGTERM
#define S_ISSOCK(x) 0
#ifndef S_IRGRP
#define S_IRGRP 0
#define S_IWGRP 0
#define S_IROTH 0
#define S_IWOTH 0
#endif
#endif
#endif

#include "arg_parser.h"
#include "lzip.h"

#ifndef O_BINARY
#define O_BINARY 0
#endif

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

int verbosity = 0;

namespace {

const char * const program_name = "plzip";
const char * const program_year = "2021";
const char * invocation_name = program_name;		// default value

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

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

enum Mode { m_compress, m_decompress, m_list, m_test };

/* Variables used in signal handler context.
   They are not declared volatile because the handler never returns. */
std::string output_filename;
int outfd = -1;
bool delete_output_on_interrupt = false;


void show_help( const long num_online )
  {
  std::printf( "Plzip is a massively parallel (multi-threaded) implementation of lzip, fully\n"
               "compatible with lzip 1.4 or newer. Plzip uses the compression library lzlib.\n"
               "\nLzip is a lossless data compressor with a user interface similar to the one\n"
               "of gzip or bzip2. Lzip uses a simplified form of the 'Lempel-Ziv-Markov\n"
               "chain-Algorithm' (LZMA) stream format, chosen to maximize safety and\n"
               "interoperability. Lzip can compress about as fast as gzip (lzip -0) or\n"
               "compress most files more than bzip2 (lzip -9). Decompression speed is\n"
               "intermediate between gzip and bzip2. Lzip is better than gzip and bzip2 from\n"
               "a data recovery perspective. Lzip has been designed, written, and tested\n"
               "with great care to replace gzip and bzip2 as the standard general-purpose\n"
               "compressed format for unix-like systems.\n"
               "\nPlzip can compress/decompress large files on multiprocessor machines much\n"
               "faster than lzip, at the cost of a slightly reduced compression ratio (0.4\n"
               "to 2 percent larger compressed files). Note that the number of usable\n"
               "threads is limited by file size; on files larger than a few GB plzip can use\n"
               "hundreds of processors, but on files of only a few MB plzip is no faster\n"
               "than lzip.\n"
               "\nUsage: %s [options] [files]\n", invocation_name );
  std::printf( "\nOptions:\n"
               "  -h, --help                     display this help and exit\n"
               "  -V, --version                  output version information and exit\n"
               "  -a, --trailing-error           exit with error status if trailing data\n"
               "  -B, --data-size=<bytes>        set size of input data blocks [2x8=16 MiB]\n"
               "  -c, --stdout                   write to standard output, keep input files\n"
               "  -d, --decompress               decompress\n"
               "  -f, --force                    overwrite existing output files\n"
               "  -F, --recompress               force re-compression of compressed files\n"
               "  -k, --keep                     keep (don't delete) input files\n"
               "  -l, --list                     print (un)compressed file sizes\n"
               "  -m, --match-length=<bytes>     set match length limit in bytes [36]\n"
               "  -n, --threads=<n>              set number of (de)compression threads [%ld]\n"
               "  -o, --output=<file>            write to <file>, keep input files\n"
               "  -q, --quiet                    suppress all messages\n"
               "  -s, --dictionary-size=<bytes>  set dictionary size limit in bytes [8 MiB]\n"
               "  -t, --test                     test compressed file integrity\n"
               "  -v, --verbose                  be verbose (a 2nd -v gives more)\n"
               "  -0 .. -9                       set compression level [default 6]\n"
               "      --fast                     alias for -0\n"
               "      --best                     alias for -9\n"
               "      --loose-trailing           allow trailing data seeming corrupt header\n"
               "      --in-slots=<n>             number of 1 MiB input packets buffered [4]\n"
               "      --out-slots=<n>            number of 1 MiB output packets buffered [64]\n"
               "      --check-lib                compare version of lzlib.h with liblz.{a,so}\n",
               num_online );
  if( verbosity >= 1 )
    {
    std::printf( "      --debug=<level>        print mode(2), debug statistics(1) to stderr\n" );
    }
  std::printf( "\nIf no file names are given, or if a file is '-', plzip compresses or\n"
               "decompresses from standard input to standard output.\n"
               "Numbers may be followed by a multiplier: k = kB = 10^3 = 1000,\n"
               "Ki = KiB = 2^10 = 1024, M = 10^6, Mi = 2^20, G = 10^9, Gi = 2^30, etc...\n"
               "Dictionary sizes 12 to 29 are interpreted as powers of two, meaning 2^12\n"
               "to 2^29 bytes.\n"
               "\nThe bidimensional parameter space of LZMA can't be mapped to a linear\n"
               "scale optimal for all files. If your files are large, very repetitive,\n"
               "etc, you may need to use the options --dictionary-size and --match-length\n"
               "directly to achieve optimal performance.\n"
               "\nTo extract all the files from archive 'foo.tar.lz', use the commands\n"
               "'tar -xf foo.tar.lz' or 'plzip -cd foo.tar.lz | tar -xf -'.\n"
               "\nExit status: 0 for a normal exit, 1 for environmental problems (file\n"
               "not found, invalid flags, I/O errors, etc), 2 to indicate a corrupt or\n"
               "invalid input file, 3 for an internal consistency error (eg, bug) which\n"
               "caused plzip to panic.\n"
               "\nReport bugs to lzip-bug@nongnu.org\n"
               "Plzip home page: http://www.nongnu.org/lzip/plzip.html\n" );
  }


void show_version()
  {
  std::printf( "%s %s\n", program_name, PROGVERSION );
  std::printf( "Copyright (C) 2009 Laszlo Ersek.\n" );
  std::printf( "Copyright (C) %s Antonio Diaz Diaz.\n", program_year );
  std::printf( "Using lzlib %s\n", LZ_version() );
  std::printf( "License GPLv2+: GNU GPL version 2 or later <http://gnu.org/licenses/gpl.html>\n"
               "This is free software: you are free to change and redistribute it.\n"
               "There is NO WARRANTY, to the extent permitted by law.\n" );
  }


int check_lib()
  {
  bool warning = false;
  if( std::strcmp( LZ_version_string, LZ_version() ) != 0 )
    { warning = true;
      if( verbosity >= 0 )
        std::printf( "warning: LZ_version_string != LZ_version() (%s vs %s)\n",
                     LZ_version_string, LZ_version() ); }
#if defined LZ_API_VERSION && LZ_API_VERSION >= 1012
  if( LZ_API_VERSION != LZ_api_version() )
    { warning = true;
      if( verbosity >= 0 )
        std::printf( "warning: LZ_API_VERSION != LZ_api_version() (%u vs %u)\n",
                     LZ_API_VERSION, LZ_api_version() ); }
#endif
  if( verbosity >= 1 )
    {
    std::printf( "Using lzlib %s\n", LZ_version() );
#if !defined LZ_API_VERSION
    std::fputs( "LZ_API_VERSION is not defined.\n", stdout );
#elif LZ_API_VERSION >= 1012
    std::printf( "Using LZ_API_VERSION = %u\n", LZ_api_version() );
#else
    std::printf( "Compiled with LZ_API_VERSION = %u. "
                 "Using an unknown LZ_API_VERSION\n", LZ_API_VERSION );
#endif
    }
  return warning;
  }

} // end namespace

void Pretty_print::operator()( const char * const msg ) const
  {
  if( verbosity >= 0 )
    {
    if( first_post )
      {
      first_post = false;
      std::fputs( padded_name.c_str(), stderr );
      if( !msg ) std::fflush( stderr );
      }
    if( msg ) std::fprintf( stderr, "%s\n", msg );
    }
  }


const char * bad_version( const unsigned version )
  {
  static char buf[80];
  snprintf( buf, sizeof buf, "Version %u member format not supported.",
            version );
  return buf;
  }


const char * format_ds( const unsigned dictionary_size )
  {
  enum { bufsize = 16, factor = 1024 };
  static char buf[bufsize];
  const char * const prefix[8] =
    { "Ki", "Mi", "Gi", "Ti", "Pi", "Ei", "Zi", "Yi" };
  const char * p = "";
  const char * np = "  ";
  unsigned num = dictionary_size;
  bool exact = ( num % factor == 0 );

  for( int i = 0; i < 8 && ( num > 9999 || ( exact && num >= factor ) ); ++i )
    { num /= factor; if( num % factor != 0 ) exact = false;
      p = prefix[i]; np = ""; }
  snprintf( buf, bufsize, "%s%4u %sB", np, num, p );
  return buf;
  }


void show_header( const unsigned dictionary_size )
  {
  std::fprintf( stderr, "dict %s, ", format_ds( dictionary_size ) );
  }

namespace {

unsigned long long getnum( const char * const ptr,
                           const unsigned long long llimit,
                           const unsigned long long ulimit )
  {
  char * tail;
  errno = 0;
  unsigned long long result = strtoull( ptr, &tail, 0 );
  if( tail == ptr )
    {
    show_error( "Bad or missing numerical argument.", 0, true );
    std::exit( 1 );
    }

  if( !errno && tail[0] )
    {
    const unsigned factor = ( tail[1] == 'i' ) ? 1024 : 1000;
    int exponent = 0;				// 0 = bad multiplier
    switch( tail[0] )
      {
      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; break;
      case 'k': if( factor == 1000 ) exponent = 1; break;
      }
    if( exponent <= 0 )
      {
      show_error( "Bad multiplier in numerical argument.", 0, true );
      std::exit( 1 );
      }
    for( int i = 0; i < exponent; ++i )
      {
      if( ulimit / factor >= result ) result *= factor;
      else { errno = ERANGE; break; }
      }
    }
  if( !errno && ( result < llimit || result > ulimit ) ) errno = ERANGE;
  if( errno )
    {
    show_error( "Numerical argument out of limits." );
    std::exit( 1 );
    }
  return result;
  }


int get_dict_size( const char * const arg )
  {
  char * tail;
  const long bits = std::strtol( arg, &tail, 0 );
  if( bits >= LZ_min_dictionary_bits() &&
      bits <= LZ_max_dictionary_bits() && *tail == 0 )
    return 1 << bits;
  int dictionary_size = getnum( arg, LZ_min_dictionary_size(),
                                     LZ_max_dictionary_size() );
  if( dictionary_size == 65535 ) ++dictionary_size;	// no fast encoder
  return dictionary_size;
  }


void set_mode( Mode & program_mode, const Mode new_mode )
  {
  if( program_mode != m_compress && program_mode != new_mode )
    {
    show_error( "Only one operation can be specified.", 0, true );
    std::exit( 1 );
    }
  program_mode = new_mode;
  }


int extension_index( const std::string & name )
  {
  for( int eindex = 0; known_extensions[eindex].from; ++eindex )
    {
    const std::string ext( known_extensions[eindex].from );
    if( name.size() > ext.size() &&
        name.compare( name.size() - ext.size(), ext.size(), ext ) == 0 )
      return eindex;
    }
  return -1;
  }


void set_c_outname( const std::string & name, const bool filenames_given,
                    const bool force_ext )
  {
  /* zupdate < 1.9 depends on lzip adding the extension '.lz' to name when
     reading from standard input. */
  output_filename = name;
  if( force_ext ||
      ( !filenames_given && extension_index( output_filename ) < 0 ) )
    output_filename += known_extensions[0].from;
  }


void set_d_outname( const std::string & name, const int eindex )
  {
  if( eindex >= 0 )
    {
    const std::string from( known_extensions[eindex].from );
    if( name.size() > from.size() )
      {
      output_filename.assign( name, 0, name.size() - from.size() );
      output_filename += known_extensions[eindex].to;
      return;
      }
    }
  output_filename = name; output_filename += ".out";
  if( verbosity >= 1 )
    std::fprintf( stderr, "%s: Can't guess original name for '%s' -- using '%s'\n",
                  program_name, name.c_str(), output_filename.c_str() );
  }

} // end namespace

int open_instream( const char * const name, struct stat * const in_statsp,
                   const bool one_to_one, const bool reg_only )
  {
  int infd = open( name, O_RDONLY | O_BINARY );
  if( infd < 0 )
    show_file_error( name, "Can't open input file", errno );
  else
    {
    const int i = fstat( infd, in_statsp );
    const mode_t mode = in_statsp->st_mode;
    const bool can_read = ( i == 0 && !reg_only &&
                            ( S_ISBLK( mode ) || S_ISCHR( mode ) ||
                              S_ISFIFO( mode ) || S_ISSOCK( mode ) ) );
    if( i != 0 || ( !S_ISREG( mode ) && ( !can_read || one_to_one ) ) )
      {
      if( verbosity >= 0 )
        std::fprintf( stderr, "%s: Input file '%s' is not a regular file%s.\n",
                      program_name, name, ( can_read && one_to_one ) ?
                      ",\n       and neither '-c' nor '-o' were specified" : "" );
      close( infd );
      infd = -1;
      }
    }
  return infd;
  }

namespace {

int open_instream2( const char * const name, struct stat * const in_statsp,
                    const Mode program_mode, const int eindex,
                    const bool one_to_one, const bool recompress )
  {
  if( program_mode == m_compress && !recompress && eindex >= 0 )
    {
    if( verbosity >= 0 )
      std::fprintf( stderr, "%s: Input file '%s' already has '%s' suffix.\n",
                    program_name, name, known_extensions[eindex].from );
    return -1;
    }
  return open_instream( name, in_statsp, one_to_one, false );
  }


bool open_outstream( const bool force, const bool protect )
  {
  const mode_t usr_rw = S_IRUSR | S_IWUSR;
  const mode_t all_rw = usr_rw | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH;
  const mode_t outfd_mode = protect ? usr_rw : all_rw;
  int flags = O_CREAT | O_WRONLY | O_BINARY;
  if( force ) flags |= O_TRUNC; else flags |= O_EXCL;

  outfd = open( output_filename.c_str(), flags, outfd_mode );
  if( outfd >= 0 ) delete_output_on_interrupt = true;
  else if( verbosity >= 0 )
    {
    if( errno == EEXIST )
      std::fprintf( stderr, "%s: Output file '%s' already exists, skipping.\n",
                    program_name, output_filename.c_str() );
    else
      std::fprintf( stderr, "%s: Can't create output file '%s': %s\n",
                    program_name, output_filename.c_str(), std::strerror( errno ) );
    }
  return ( outfd >= 0 );
  }


void set_signals( void (*action)(int) )
  {
  std::signal( SIGHUP, action );
  std::signal( SIGINT, action );
  std::signal( SIGTERM, action );
  }

} // end namespace

/* This can be called from any thread, main thread or sub-threads alike,
   since they all call common helper functions like 'xlock' that call
   cleanup_and_fail() in case of an error.
*/
void cleanup_and_fail( const int retval )
  {
  // only one thread can delete and exit
  static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;

  set_signals( SIG_IGN );			// ignore signals
  pthread_mutex_lock( &mutex );		// ignore errors to avoid loop
  const int saved_verbosity = verbosity;
  verbosity = -1;		// suppress messages from other threads
  if( delete_output_on_interrupt )
    {
    delete_output_on_interrupt = false;
    if( saved_verbosity >= 0 )
      std::fprintf( stderr, "%s: Deleting output file '%s', if it exists.\n",
                    program_name, output_filename.c_str() );
    if( outfd >= 0 ) { close( outfd ); outfd = -1; }
    if( std::remove( output_filename.c_str() ) != 0 && errno != ENOENT &&
        saved_verbosity >= 0 )
      std::fprintf( stderr, "%s: WARNING: deletion of output file "
                    "(apparently) failed.\n", program_name );
    }
  std::exit( retval );
  }

namespace {

extern "C" void signal_handler( int )
  {
  show_error( "Control-C or similar caught, quitting." );
  cleanup_and_fail( 1 );
  }


bool check_tty_in( const char * const input_filename, const int infd,
                   const Mode program_mode, int & retval )
  {
  if( ( program_mode == m_decompress || program_mode == m_test ) &&
      isatty( infd ) )				// for example /dev/tty
    { show_file_error( input_filename,
                       "I won't read compressed data from a terminal." );
      close( infd ); set_retval( retval, 1 );
      if( program_mode != m_test ) cleanup_and_fail( retval );
      return false; }
  return true;
  }

bool check_tty_out( const Mode program_mode )
  {
  if( program_mode == m_compress && isatty( outfd ) )
    { show_file_error( output_filename.size() ?
                       output_filename.c_str() : "(stdout)",
                       "I won't write compressed data to a terminal." );
      return false; }
  return true;
  }


// Set permissions, owner, and times.
void close_and_set_permissions( const struct stat * const in_statsp )
  {
  bool warning = false;
  if( in_statsp )
    {
    const mode_t mode = in_statsp->st_mode;
    // fchown will in many cases return with EPERM, which can be safely ignored.
    if( fchown( outfd, in_statsp->st_uid, in_statsp->st_gid ) == 0 )
      { if( fchmod( outfd, mode ) != 0 ) warning = true; }
    else
      if( errno != EPERM ||
          fchmod( outfd, mode & ~( S_ISUID | S_ISGID | S_ISVTX ) ) != 0 )
        warning = true;
    }
  if( close( outfd ) != 0 )
    {
    show_error( "Error closing output file", errno );
    cleanup_and_fail( 1 );
    }
  outfd = -1;
  delete_output_on_interrupt = false;
  if( in_statsp )
    {
    struct utimbuf t;
    t.actime = in_statsp->st_atime;
    t.modtime = in_statsp->st_mtime;
    if( utime( output_filename.c_str(), &t ) != 0 ) warning = true;
    }
  if( warning && verbosity >= 1 )
    show_error( "Can't change output file attributes." );
  }

} // end namespace


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


void show_file_error( const char * const filename, const char * const msg,
                      const int errcode )
  {
  if( verbosity >= 0 )
    std::fprintf( stderr, "%s: %s: %s%s%s\n", program_name, filename, msg,
                  ( errcode > 0 ) ? ": " : "",
                  ( errcode > 0 ) ? std::strerror( errcode ) : "" );
  }


void internal_error( const char * const msg )
  {
  if( verbosity >= 0 )
    std::fprintf( stderr, "%s: internal error: %s\n", program_name, msg );
  std::exit( 3 );
  }


void show_progress( const unsigned long long packet_size,
                    const unsigned long long cfile_size,
                    const Pretty_print * const p )
  {
  static unsigned long long csize = 0;		// file_size / 100
  static unsigned long long pos = 0;
  static const Pretty_print * pp = 0;
  static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
  static bool enabled = true;

  if( !enabled ) return;
  if( p )					// initialize static vars
    {
    if( verbosity < 2 || !isatty( STDERR_FILENO ) ) { enabled = false; return; }
    csize = cfile_size; pos = 0; pp = p;
    }
  if( pp )
    {
    xlock( &mutex );
    pos += packet_size;
    if( csize > 0 )
      std::fprintf( stderr, "%4llu%%  %.1f MB\r", pos / csize, pos / 1000000.0 );
    else
      std::fprintf( stderr, "  %.1f MB\r", pos / 1000000.0 );
    pp->reset(); (*pp)();			// restore cursor position
    xunlock( &mutex );
    }
  }


#if defined(__MSVCRT__)
#include <windows.h>
#define _SC_NPROCESSORS_ONLN   1
#define _SC_THREAD_THREADS_MAX 2

long sysconf( int flag )
  {
  if( flag == _SC_NPROCESSORS_ONLN )
    {
    SYSTEM_INFO si;
    GetSystemInfo( &si );
    return si.dwNumberOfProcessors;
    }
  if( flag != _SC_THREAD_THREADS_MAX ) errno = EINVAL;
  return -1;		// unlimited threads or error
  }

#endif	// __MSVCRT__


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 Lzma_options option_mapping[] =
    {
    {   65535,  16 },		// -0 (65535,16 chooses fast encoder)
    { 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
  Lzma_options encoder_options = option_mapping[6];	// default = "-6"
  std::string default_output_filename;
  std::vector< std::string > filenames;
  int data_size = 0;
  int debug_level = 0;
  int num_workers = 0;		// start this many worker threads
  int in_slots = 4;
  int out_slots = 64;
  Mode program_mode = m_compress;
  bool force = false;
  bool ignore_trailing = true;
  bool keep_input_files = false;
  bool loose_trailing = false;
  bool recompress = false;
  bool to_stdout = false;
  if( argc > 0 ) invocation_name = argv[0];

  enum { opt_chk = 256, opt_dbg, opt_in, opt_lt, opt_out };
  const Arg_parser::Option options[] =
    {
    { '0', "fast",              Arg_parser::no  },
    { '1', 0,                   Arg_parser::no  },
    { '2', 0,                   Arg_parser::no  },
    { '3', 0,                   Arg_parser::no  },
    { '4', 0,                   Arg_parser::no  },
    { '5', 0,                   Arg_parser::no  },
    { '6', 0,                   Arg_parser::no  },
    { '7', 0,                   Arg_parser::no  },
    { '8', 0,                   Arg_parser::no  },
    { '9', "best",              Arg_parser::no  },
    { 'a', "trailing-error",    Arg_parser::no  },
    { 'b', "member-size",       Arg_parser::yes },
    { 'B', "data-size",         Arg_parser::yes },
    { 'c', "stdout",            Arg_parser::no  },
    { 'd', "decompress",        Arg_parser::no  },
    { 'f', "force",             Arg_parser::no  },
    { 'F', "recompress",        Arg_parser::no  },
    { 'h', "help",              Arg_parser::no  },
    { 'k', "keep",              Arg_parser::no  },
    { 'l', "list",              Arg_parser::no  },
    { 'm', "match-length",      Arg_parser::yes },
    { 'n', "threads",           Arg_parser::yes },
    { 'o', "output",            Arg_parser::yes },
    { 'q', "quiet",             Arg_parser::no  },
    { 's', "dictionary-size",   Arg_parser::yes },
    { 'S', "volume-size",       Arg_parser::yes },
    { 't', "test",              Arg_parser::no  },
    { 'v', "verbose",           Arg_parser::no  },
    { 'V', "version",           Arg_parser::no  },
    { opt_chk, "check-lib",     Arg_parser::no  },
    { opt_dbg, "debug",         Arg_parser::yes },
    { opt_in, "in-slots",       Arg_parser::yes },
    { opt_lt, "loose-trailing", Arg_parser::no  },
    { opt_out, "out-slots",     Arg_parser::yes },
    {  0, 0,                    Arg_parser::no  } };

  const Arg_parser parser( argc, argv, options );
  if( parser.error().size() )				// bad option
    { show_error( parser.error().c_str(), 0, true ); return 1; }

  const long num_online = std::max( 1L, sysconf( _SC_NPROCESSORS_ONLN ) );
  long max_workers = sysconf( _SC_THREAD_THREADS_MAX );
  if( max_workers < 1 || max_workers > INT_MAX / (int)sizeof (pthread_t) )
    max_workers = INT_MAX / sizeof (pthread_t);

  int argind = 0;
  for( ; argind < parser.arguments(); ++argind )
    {
    const int code = parser.code( argind );
    if( !code ) break;					// no more options
    const std::string & sarg = parser.argument( argind );
    const char * const arg = sarg.c_str();
    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 'a': ignore_trailing = false; break;
      case 'b': break;
      case 'B': data_size = getnum( arg, 2 * LZ_min_dictionary_size(),
                                    2 * LZ_max_dictionary_size() ); break;
      case 'c': to_stdout = true; break;
      case 'd': set_mode( program_mode, m_decompress ); break;
      case 'f': force = true; break;
      case 'F': recompress = true; break;
      case 'h': show_help( num_online ); return 0;
      case 'k': keep_input_files = true; break;
      case 'l': set_mode( program_mode, m_list ); break;
      case 'm': encoder_options.match_len_limit =
                  getnum( arg, LZ_min_match_len_limit(),
                               LZ_max_match_len_limit() ); break;
      case 'n': num_workers = getnum( arg, 1, max_workers ); break;
      case 'o': if( sarg == "-" ) to_stdout = true;
                else { default_output_filename = sarg; } break;
      case 'q': verbosity = -1; break;
      case 's': encoder_options.dictionary_size = get_dict_size( arg );
                break;
      case 'S': break;
      case 't': set_mode( program_mode, m_test ); break;
      case 'v': if( verbosity < 4 ) ++verbosity; break;
      case 'V': show_version(); return 0;
      case opt_chk: return check_lib();
      case opt_dbg: debug_level = getnum( arg, 0, 3 ); break;
      case opt_in: in_slots = getnum( arg, 1, 64 ); break;
      case opt_lt: loose_trailing = true; break;
      case opt_out: out_slots = getnum( arg, 1, 1024 ); break;
      default : internal_error( "uncaught option." );
      }
    } // end process options

  if( LZ_version()[0] < '1' )
    { show_error( "Wrong library version. At least lzlib 1.0 is required." );
      return 1; }

#if defined(__MSVCRT__) || defined(__OS2__)
  setmode( STDIN_FILENO, O_BINARY );
  setmode( STDOUT_FILENO, O_BINARY );
#endif

  bool filenames_given = false;
  for( ; argind < parser.arguments(); ++argind )
    {
    filenames.push_back( parser.argument( argind ) );
    if( filenames.back() != "-" ) filenames_given = true;
    }
  if( filenames.empty() ) filenames.push_back("-");

  if( program_mode == m_list )
    return list_files( filenames, ignore_trailing, loose_trailing );

  const bool fast = encoder_options.dictionary_size == 65535 &&
                    encoder_options.match_len_limit == 16;
  if( data_size <= 0 )
    {
    if( fast ) data_size = 1 << 20;
    else data_size = 2 * std::max( 65536, encoder_options.dictionary_size );
    }
  else if( !fast && data_size < encoder_options.dictionary_size )
    encoder_options.dictionary_size =
      std::max( data_size, LZ_min_dictionary_size() );

  if( num_workers <= 0 )
    {
    if( program_mode == m_compress && sizeof (void *) <= 4 )
      {
      // use less than 2.22 GiB on 32 bit systems
      const long long limit = ( 27LL << 25 ) + ( 11LL << 27 );	// 4 * 568 MiB
      const long long mem = ( 27LL * data_size ) / 8 +
        ( fast ? 3LL << 19 : 11LL * encoder_options.dictionary_size );
      const int nmax32 = std::max( limit / mem, 1LL );
      if( max_workers > nmax32 ) max_workers = nmax32;
      }
    num_workers = std::min( num_online, max_workers );
    }

  if( program_mode == m_test ) to_stdout = false;	// apply overrides
  if( program_mode == m_test || to_stdout ) default_output_filename.clear();

  if( to_stdout && program_mode != m_test )	// check tty only once
    { outfd = STDOUT_FILENO; if( !check_tty_out( program_mode ) ) return 1; }
  else outfd = -1;

  const bool to_file = !to_stdout && program_mode != m_test &&
                       default_output_filename.size();
  if( !to_stdout && program_mode != m_test && ( filenames_given || to_file ) )
    set_signals( signal_handler );

  Pretty_print pp( filenames );

  int failed_tests = 0;
  int retval = 0;
  const bool one_to_one = !to_stdout && program_mode != m_test && !to_file;
  bool stdin_used = false;
  for( unsigned i = 0; i < filenames.size(); ++i )
    {
    std::string input_filename;
    int infd;
    struct stat in_stats;

    pp.set_name( filenames[i] );
    if( filenames[i] == "-" )
      {
      if( stdin_used ) continue; else stdin_used = true;
      infd = STDIN_FILENO;
      if( !check_tty_in( pp.name(), infd, program_mode, retval ) ) continue;
      if( one_to_one ) { outfd = STDOUT_FILENO; output_filename.clear(); }
      }
    else
      {
      const int eindex = extension_index( input_filename = filenames[i] );
      infd = open_instream2( input_filename.c_str(), &in_stats, program_mode,
                             eindex, one_to_one, recompress );
      if( infd < 0 ) { set_retval( retval, 1 ); continue; }
      if( !check_tty_in( pp.name(), infd, program_mode, retval ) ) continue;
      if( one_to_one )			// open outfd after verifying infd
        {
        if( program_mode == m_compress )
          set_c_outname( input_filename, true, true );
        else set_d_outname( input_filename, eindex );
        if( !open_outstream( force, true ) )
          { close( infd ); set_retval( retval, 1 ); continue; }
        }
      }

    if( one_to_one && !check_tty_out( program_mode ) )
      { set_retval( retval, 1 ); return retval; }	// don't delete a tty

    if( to_file && outfd < 0 )		// open outfd after verifying infd
      {
      if( program_mode == m_compress ) set_c_outname( default_output_filename,
                                       filenames_given, false );
      else output_filename = default_output_filename;
      if( !open_outstream( force, false ) || !check_tty_out( program_mode ) )
        return 1;	// check tty only once and don't try to delete a tty
      }

    const struct stat * const in_statsp =
      ( input_filename.size() && one_to_one ) ? &in_stats : 0;
    const bool infd_isreg = input_filename.size() && S_ISREG( in_stats.st_mode );
    const unsigned long long cfile_size =
      infd_isreg ? ( in_stats.st_size + 99 ) / 100 : 0;
    int tmp;
    if( program_mode == m_compress )
      tmp = compress( cfile_size, data_size, encoder_options.dictionary_size,
                      encoder_options.match_len_limit, num_workers,
                      infd, outfd, pp, debug_level );
    else
      tmp = decompress( cfile_size, num_workers, infd, outfd, pp,
                        debug_level, in_slots, out_slots, ignore_trailing,
                        loose_trailing, infd_isreg, one_to_one );
    if( close( infd ) != 0 )
      { show_file_error( pp.name(), "Error closing input file", errno );
        set_retval( tmp, 1 ); }
    set_retval( retval, tmp );
    if( tmp )
      { if( program_mode != m_test ) cleanup_and_fail( retval );
        else ++failed_tests; }

    if( delete_output_on_interrupt && one_to_one )
      close_and_set_permissions( in_statsp );
    if( input_filename.size() && !keep_input_files && one_to_one )
      std::remove( input_filename.c_str() );
    }
  if( delete_output_on_interrupt ) close_and_set_permissions( 0 );	// -o
  else if( outfd >= 0 && close( outfd ) != 0 )				// -c
    {
    show_error( "Error closing stdout", errno );
    set_retval( retval, 1 );
    }
  if( failed_tests > 0 && verbosity >= 1 && filenames.size() > 1 )
    std::fprintf( stderr, "%s: warning: %d %s failed the test.\n",
                  program_name, failed_tests,
                  ( failed_tests == 1 ) ? "file" : "files" );
  return retval;
  }