/* Lziprecover - Data recovery tool for the lzip format
   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 lziprecover to panic.
*/

#define _FILE_OFFSET_BITS 64

#include <algorithm>
#include <cctype>
#include <cerrno>
#include <climits>
#include <csignal>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <new>
#include <string>
#include <vector>
#include <fcntl.h>
#include <stdint.h>
#include <unistd.h>
#include <utime.h>
#include <sys/stat.h>
#if defined(__MSVCRT__) || defined(__OS2__) || defined(__DJGPP__)
#include <io.h>
#if defined(__MSVCRT__)
#define fchmod(x,y) 0
#define fchown(x,y,z) 0
#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
#if defined(__DJGPP__)
#define S_ISSOCK(x) 0
#define S_ISVTX 0
#endif
#endif

#include "arg_parser.h"
#include "lzip.h"
#include "decoder.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;

const char * const program_name = "lziprecover";
std::string output_filename;	// global vars for output file
int outfd = -1;			// see 'delete_output_on_interrupt' below

namespace {

const char * invocation_name = program_name;		// default value

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

enum Mode { m_none, m_alone_to_lz, m_debug_decompress, m_debug_delay,
            m_debug_repair, m_decompress, m_dump, m_list, m_md5sum, m_merge,
            m_nrep_stats, m_range_dec, m_remove, m_repair, m_reproduce,
            m_show_packets, m_split, m_strip, m_test, m_unzcrash };

/* Variable used in signal handler context.
   It is not declared volatile because the handler never returns. */
bool delete_output_on_interrupt = false;


void show_help()
  {
  std::printf( "Lziprecover is a data recovery tool and decompressor for files in the lzip\n"
               "compressed data format (.lz). Lziprecover is able to repair slightly damaged\n"
               "files, produce a correct file by merging the good parts of two or more\n"
               "damaged copies, reproduce a missing (zeroed) sector using a reference file,\n"
               "extract data from damaged files, decompress files, and test integrity of\n"
               "files.\n"
               "\nLziprecover can repair perfectly most files with small errors (up to one\n"
               "single-byte error per member), without the need of any extra redundance\n"
               "at all. Losing an entire archive just because of a corrupt byte near the\n"
               "beginning is a thing of the past.\n"
               "\nLziprecover can remove the damaged members from multimember files, for\n"
               "example multimember tar.lz archives.\n"
               "\nLziprecover provides random access to the data in multimember files; it only\n"
               "decompresses the members containing the desired data.\n"
               "\nLziprecover facilitates the management of metadata stored as trailing data\n"
               "in lzip files.\n"
               "\nLziprecover is not a replacement for regular backups, but a last line of\n"
               "defense for the case where the backups are also damaged.\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"
               "  -A, --alone-to-lz             convert lzma-alone files to lzip format\n"
               "  -c, --stdout                  write to standard output, keep input files\n"
               "  -d, --decompress              decompress\n"
               "  -D, --range-decompress=<n-m>  decompress a range of bytes to stdout\n"
               "  -e, --reproduce               try to reproduce a zeroed sector in file\n"
               "      --lzip-level=N|a|m[N]     reproduce one level, all, or match length\n"
               "      --lzip-name=<name>        name of lzip executable for --reproduce\n"
               "      --reference-file=<file>   reference file for --reproduce\n"
               "  -f, --force                   overwrite existing output files\n"
               "  -i, --ignore-errors           ignore some errors in -d, -D, -l, -t, --dump\n"
               "  -k, --keep                    keep (don't delete) input files\n"
               "  -l, --list                    print (un)compressed file sizes\n"
               "  -m, --merge                   correct errors in file using several copies\n"
               "  -o, --output=<file>           place the output into <file>\n"
               "  -q, --quiet                   suppress all messages\n"
               "  -R, --repair                  try to repair a small error in file\n"
               "  -s, --split                   split multimember file in single-member files\n"
               "  -t, --test                    test compressed file integrity\n"
               "  -v, --verbose                 be verbose (a 2nd -v gives more)\n"
               "      --loose-trailing          allow trailing data seeming corrupt header\n"
               "      --dump=<list>:d:t         dump members listed/damaged, tdata to stdout\n"
               "      --remove=<list>:d:t       remove members, tdata from files in place\n"
               "      --strip=<list>:d:t        copy files to stdout stripping members given\n" );
  if( verbosity >= 1 )
    {
    std::printf( "\nDebug options for experts:\n"
                 "  -E, --debug-reproduce=<range>[,ss]  set range to 0 and try to reproduce file\n"
                 "  -M, --md5sum                      print the MD5 digests of the input files\n"
                 "  -S, --nrep-stats[=<val>]          print stats of N-byte repeated sequences\n"
                 "  -U, --unzcrash                    test 1-bit errors in the input file\n"
                 "  -W, --debug-decompress=<pos>,<val>  set pos to val and decompress to stdout\n"
                 "  -X, --show-packets[=<pos>,<val>]  show in stdout the decoded LZMA packets\n"
                 "  -Y, --debug-delay=<range>         find max error detection delay in <range>\n"
                 "  -Z, --debug-repair=<pos>,<val>    test repair one-byte error at <pos>\n" );
    }
  std::printf( "\nIf no file names are given, or if a file is '-', lziprecover decompresses\n"
               "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"
               "\nTo extract all the files from archive 'foo.tar.lz', use the commands\n"
               "'tar -xf foo.tar.lz' or 'lziprecover -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 lziprecover to panic.\n"
               "\nReport bugs to lzip-bug@nongnu.org\n"
               "Lziprecover home page: http://www.nongnu.org/lzip/lziprecover.html\n" );
  }

} // end namespace

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


#include "main_common.cc"


// Colon-separated list of "damaged", "tdata", [r][^]<list> (1 1,3-5,8)
void Member_list::parse( const char * p )
  {
  while( true )
    {
    const char * tp = p;	// points to terminator; ':' or null
    while( *tp && *tp != ':' ) ++tp;
    const unsigned len = tp - p;
    if( std::isalpha( *(const unsigned char *)p ) )
      {
      if( len <= 7 && std::strncmp( "damaged", p, len ) == 0 )
        { damaged = true; goto next; }
      if( len <= 5 && std::strncmp( "tdata", p, len ) == 0 )
        { tdata = true; goto next; }
      }
    {
    const bool reverse = ( *p == 'r' );
    if( reverse ) ++p;
    if( *p == '^' ) { ++p; if( reverse ) rin = false; else in = false; }
    std::vector< Block > * rvp = reverse ? &rrange_vector : &range_vector;
    while( std::isdigit( *(const unsigned char *)p ) )
      {
      const char * tail;
      const int pos = getnum( p, 0, 1, INT_MAX, &tail ) - 1;
      if( rvp->size() && pos < rvp->back().end() ) break;
      const int size = (*tail == '-') ?
        getnum( tail + 1, 0, pos + 1, INT_MAX, &tail ) - pos : 1;
      rvp->push_back( Block( pos, size ) );
      if( tail == tp ) goto next;
      if( *tail == ',' ) p = tail + 1; else break;
      }
    }
    show_error( "Invalid list of members." );
    std::exit( 1 );
next:
    if( *(p = tp) != 0 ) ++p; else return;
    }
  }


namespace {

// Recognized formats: <digit> 'a' m[<match_length>]
//
int parse_lzip_level( const char * const p )
  {
  if( *p == 'a' || std::isdigit( *(const unsigned char *)p ) ) return *p;
  if( *p != 'm' )
    {
    show_error( "Bad argument in option '--lzip-level'.", 0, true );
    std::exit( 1 );
    }
  if( p[1] == 0 ) return -1;
  return -getnum( p + 1, 0, min_match_len_limit, max_match_len );
  }


/* Recognized format: <range>[,<sector_size>]
   range formats: <begin> <begin>-<end> <begin>,<size> ,<size>
*/
void parse_range( const char * const ptr, Block & range,
                  int * const sector_sizep = 0 )
  {
  const char * tail = ptr;
  long long value =
    ( ptr[0] == ',' ) ? 0 : getnum( ptr, 0, 0, INT64_MAX - 1, &tail );
  if( tail[0] == 0 || tail[0] == ',' || tail[0] == '-' )
    {
    range.pos( value );
    if( tail[0] == 0 ) { range.size( INT64_MAX - value ); return; }
    const bool is_size = ( tail[0] == ',' );
    if( sector_sizep && tail[1] == ',' ) { value = INT64_MAX - value; ++tail; }
    else value = getnum( tail + 1, 0, 1, INT64_MAX, &tail );	// size
    if( is_size || value > range.pos() )
      {
      if( !is_size ) value -= range.pos();
      if( INT64_MAX - range.pos() >= value )
        {
        range.size( value );
        if( sector_sizep && tail[0] == ',' )
          *sector_sizep = getnum( tail + 1, 0, 8, INT_MAX );
        return;
        }
      }
    }
  show_error( "Bad decompression range.", 0, true );
  std::exit( 1 );
  }


// Recognized formats: <pos>,<value> <pos>,+<value> <pos>,f<value>
//
void parse_pos_value( const char * const ptr, Bad_byte & bad_byte )
  {
  const char * tail;
  bad_byte.pos = getnum( ptr, 0, 0, INT64_MAX, &tail );
  if( tail[0] != ',' )
    {
    show_error( "Bad separator between <pos> and <val>.", 0, true );
    std::exit( 1 );
    }
  if( tail[1] == '+' ) { ++tail; bad_byte.mode = Bad_byte::delta; }
  else if( tail[1] == 'f' ) { ++tail; bad_byte.mode = Bad_byte::flip; }
  else bad_byte.mode = Bad_byte::literal;
  bad_byte.value = getnum( tail + 1, 0, 0, 255 );
  }


void one_file( const int files )
  {
  if( files != 1 )
    {
    show_error( "You must specify exactly 1 file.", 0, true );
    std::exit( 1 );
    }
  }


void set_mode( Mode & program_mode, const Mode new_mode )
  {
  if( program_mode != m_none && 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_a_outname( const std::string & name )
  {
  output_filename = name;
  if( name.size() > 5 && name.compare( name.size() - 5, 5, ".lzma" ) == 0 )
    output_filename.erase( name.size() - 2 );
  else if( name.size() > 4 && name.compare( name.size() - 4, 4, ".tlz" ) == 0 )
    output_filename.insert( name.size() - 2, "ar." );
  else if( name.size() <= 3 || name.compare( name.size() - 3, 3, ".lz" ) != 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;
  }


int open_truncable_stream( const char * const name,
                           struct stat * const in_statsp )
  {
  int fd = open( name, O_RDWR | O_BINARY );
  if( fd < 0 )
    show_file_error( name, "Can't open input file", errno );
  else
    {
    const int i = fstat( fd, in_statsp );
    const mode_t mode = in_statsp->st_mode;
    if( i != 0 || !S_ISREG( mode ) )
      { show_file_error( name, "Not a regular file." ); close( fd ); fd = -1; }
    }
  return fd;
  }


bool open_outstream( const bool force, const bool protect,
                     const bool rw, const bool skipping )
  {
  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 | ( rw ? O_RDWR : 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%s.\n",
                    program_name, output_filename.c_str(), skipping ?
                    ", skipping" : ". Use '--force' to overwrite it" );
    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 );
  }


bool file_exists( const std::string & filename )
  {
  struct stat st;
  if( stat( filename.c_str(), &st ) == 0 )
    {
    if( verbosity >= 0 )
      std::fprintf( stderr, "%s: Output file '%s' already exists."
                            " Use '--force' to overwrite it.\n",
                    program_name, filename.c_str() );
    return true;
    }
  return false;
  }


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


void cleanup_and_fail( const int retval )
  {
  set_signals( SIG_IGN );			// ignore signals
  if( delete_output_on_interrupt )
    {
    delete_output_on_interrupt = false;
    if( 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 )
      show_error( "WARNING: deletion of output file (apparently) failed." );
    }
  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( isatty( infd ) )			// all modes read compressed data
    { 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_alone_to_lz && 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." );
  }


unsigned char xdigit( const unsigned value )
  {
  if( value <= 9 ) return '0' + value;
  if( value <= 15 ) return 'A' + value - 10;
  return 0;
  }


bool show_trailing_data( const uint8_t * const data, const int size,
                         const Pretty_print & pp, const bool all,
                         const int ignore_trailing )	// -1 = show
  {
  if( verbosity >= 4 || ignore_trailing <= 0 )
    {
    std::string msg;
    if( !all ) msg = "first bytes of ";
    msg += "trailing data = ";
    for( int i = 0; i < size; ++i )
      {
      msg += xdigit( data[i] >> 4 );
      msg += xdigit( data[i] & 0x0F );
      msg += ' ';
      }
    msg += '\'';
    for( int i = 0; i < size; ++i )
      { if( std::isprint( data[i] ) ) msg += data[i]; else msg += '.'; }
    msg += '\'';
    pp( msg.c_str() );
    if( ignore_trailing == 0 ) show_file_error( pp.name(), trailing_msg );
    }
  return ( ignore_trailing > 0 );
  }


int decompress( const unsigned long long cfile_size, const int infd,
                const Pretty_print & pp, const bool ignore_errors,
                const bool ignore_trailing, const bool loose_trailing,
                const bool testing )
  {
  int retval = 0;
  unsigned long long partial_file_pos = 0;
  Range_decoder rdec( infd );
  for( bool first_member = true; ; first_member = false )
    {
    Lzip_header header;
    rdec.reset_member_position();
    const int size = rdec.read_header_carefully( header, ignore_errors );
    if( rdec.finished() ||			// End Of File
        ( size < Lzip_header::size && !rdec.find_header( header ) ) )
      {
      if( first_member )
        { show_file_error( pp.name(), "File ends unexpectedly at member header." );
          retval = 2; }
      else if( header.verify_prefix( size ) )
        { pp( "Truncated header in multimember file." );
          show_trailing_data( header.data, size, pp, true, -1 );
          retval = 2; }
      else if( size > 0 && !show_trailing_data( header.data, size, pp,
                                                true, ignore_trailing ) )
        retval = 2;
      break;
      }
    if( !header.verify_magic() )
      {
      if( first_member )
        { show_file_error( pp.name(), bad_magic_msg ); retval = 2; }
      else if( !loose_trailing && header.verify_corrupt() )
        { pp( corrupt_mm_msg );
          show_trailing_data( header.data, size, pp, false, -1 );
          retval = 2; }
      else if( !show_trailing_data( header.data, size, pp, false, ignore_trailing ) )
        retval = 2;
      if( ignore_errors ) { pp.reset(); continue; } else break;
      }
    if( !header.verify_version() )
      { pp( bad_version( header.version() ) ); retval = 2;
        if( ignore_errors ) { pp.reset(); continue; } else break; }
    const unsigned dictionary_size = header.dictionary_size();
    if( !isvalid_ds( dictionary_size ) )
      { pp( bad_dict_msg ); retval = 2;
        if( ignore_errors ) { pp.reset(); continue; } else break; }

    if( verbosity >= 2 || ( verbosity == 1 && first_member ) ) pp();

    LZ_decoder decoder( rdec, dictionary_size, outfd );
    show_dprogress( cfile_size, partial_file_pos, &rdec, &pp );	// init
    const int result = decoder.decode_member( pp );
    partial_file_pos += rdec.member_position();
    if( result != 0 )
      {
      if( verbosity >= 0 && result <= 2 )
        {
        pp();
        std::fprintf( stderr, "%s at pos %llu\n", ( result == 2 ) ?
                      "File ends unexpectedly" : "Decoder error",
                      partial_file_pos );
        }
      retval = 2; if( ignore_errors ) { pp.reset(); continue; } else break;
      }
    if( verbosity >= 2 )
      { std::fputs( testing ? "ok\n" : "done\n", stderr ); pp.reset(); }
    }
  if( verbosity == 1 && retval == 0 )
    std::fputs( testing ? "ok\n" : "done\n", stderr );
  if( retval == 2 && ignore_errors ) retval = 0;
  return retval;
  }

} // end namespace

void set_signal_handler() { set_signals( signal_handler ); }

int close_outstream( const struct stat * const in_statsp )
  {
  if( delete_output_on_interrupt )
    close_and_set_permissions( in_statsp );
  if( outfd >= 0 && close( outfd ) != 0 )
    { show_error( "Error closing stdout", errno ); return 1; }
  outfd = -1;
  return 0;
  }


std::string insert_fixed( std::string name )
  {
  if( name.size() > 7 && name.compare( name.size() - 7, 7, ".tar.lz" ) == 0 )
    name.insert( name.size() - 7, "_fixed" );
  else if( name.size() > 3 && name.compare( name.size() - 3, 3, ".lz" ) == 0 )
    name.insert( name.size() - 3, "_fixed" );
  else if( name.size() > 4 && name.compare( name.size() - 4, 4, ".tlz" ) == 0 )
    name.insert( name.size() - 4, "_fixed" );
  else name += "_fixed.lz";
  return 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 show_2file_error( const char * const msg1, const char * const name1,
                       const char * const name2, const char * const msg2 )
  {
  if( verbosity >= 0 )
    std::fprintf( stderr, "%s: %s '%s' and '%s' %s\n",
                  program_name, msg1, name1, name2, msg2 );
  }


void show_dprogress( const unsigned long long cfile_size,
                     const unsigned long long partial_size,
                     const Range_decoder * const d,
                     const Pretty_print * const p )
  {
  static unsigned long long csize = 0;		// file_size / 100
  static unsigned long long psize = 0;
  static const Range_decoder * rdec = 0;
  static const Pretty_print * pp = 0;
  static int counter = 0;
  static bool enabled = true;

  if( !enabled ) return;
  if( p )					// initialize static vars
    {
    if( verbosity < 2 || !isatty( STDERR_FILENO ) ) { enabled = false; return; }
    csize = cfile_size; psize = partial_size; rdec = d; pp = p; counter = 0;
    }
  if( rdec && pp && --counter <= 0 )
    {
    const unsigned long long pos = psize + rdec->member_position();
    counter = 7;		// update display every 114688 bytes
    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
    }
  }


int main( const int argc, const char * const argv[] )
  {
  Block range( 0, 0 );
  int sector_size = INT_MAX;		// default larger than practical range
  Bad_byte bad_byte;
  Member_list member_list;
  std::string default_output_filename;
  std::vector< std::string > filenames;
  const char * lzip_name = "lzip";		// default is lzip
  const char * reference_filename = 0;
  Mode program_mode = m_none;
  int lzip_level = 0;		//  0 = test all levels and match lengths
				// '0'..'9' = level, 'a' = all levels
				// -5..-273 = match length, -1 = all lengths
  int repeated_byte = -1;	// 0 to 255, or -1 for all values
  bool force = false;
  bool ignore_errors = false;
  bool ignore_trailing = true;
  bool keep_input_files = false;
  bool loose_trailing = false;
  bool to_stdout = false;
  if( argc > 0 ) invocation_name = argv[0];

  enum { opt_du = 256, opt_lt, opt_lzl, opt_lzn, opt_ref, opt_re, opt_st };
  const Arg_parser::Option options[] =
    {
    { 'a', "trailing-error",     Arg_parser::no  },
    { 'A', "alone-to-lz",        Arg_parser::no  },
    { 'c', "stdout",             Arg_parser::no  },
    { 'd', "decompress",         Arg_parser::no  },
    { 'D', "range-decompress",   Arg_parser::yes },
    { 'e', "reproduce",          Arg_parser::no  },
    { 'E', "debug-reproduce",    Arg_parser::yes },
    { 'f', "force",              Arg_parser::no  },
    { 'h', "help",               Arg_parser::no  },
    { 'i', "ignore-errors",      Arg_parser::no  },
    { 'k', "keep",               Arg_parser::no  },
    { 'l', "list",               Arg_parser::no  },
    { 'm', "merge",              Arg_parser::no  },
    { 'M', "md5sum",             Arg_parser::no  },
    { 'n', "threads",            Arg_parser::yes },
    { 'o', "output",             Arg_parser::yes },
    { 'q', "quiet",              Arg_parser::no  },
    { 'R', "repair",             Arg_parser::no  },
    { 's', "split",              Arg_parser::no  },
    { 'S', "nrep-stats",         Arg_parser::maybe },
    { 't', "test",               Arg_parser::no  },
    { 'U', "unzcrash",           Arg_parser::no  },
    { 'v', "verbose",            Arg_parser::no  },
    { 'V', "version",            Arg_parser::no  },
    { 'W', "debug-decompress",   Arg_parser::yes },
    { 'X', "show-packets",       Arg_parser::maybe },
    { 'Y', "debug-delay",        Arg_parser::yes },
    { 'Z', "debug-repair",       Arg_parser::yes },
    { opt_du,  "dump",           Arg_parser::yes },
    { opt_lt,  "loose-trailing", Arg_parser::no  },
    { opt_lzl, "lzip-level",     Arg_parser::yes },
    { opt_lzn, "lzip-name",      Arg_parser::yes },
    { opt_ref, "reference-file", Arg_parser::yes },
    { opt_re,  "remove",         Arg_parser::yes },
    { opt_st,  "strip",          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; }

  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 'a': ignore_trailing = false; break;
      case 'A': set_mode( program_mode, m_alone_to_lz ); break;
      case 'c': to_stdout = true; break;
      case 'd': set_mode( program_mode, m_decompress ); break;
      case 'D': set_mode( program_mode, m_range_dec );
                parse_range( arg, range ); break;
      case 'e': set_mode( program_mode, m_reproduce ); break;
      case 'E': set_mode( program_mode, m_reproduce );
                parse_range( arg, range, &sector_size ); break;
      case 'f': force = true; break;
      case 'h': show_help(); return 0;
      case 'i': ignore_errors = true; break;
      case 'k': keep_input_files = true; break;
      case 'l': set_mode( program_mode, m_list ); break;
      case 'm': set_mode( program_mode, m_merge ); break;
      case 'M': set_mode( program_mode, m_md5sum ); break;
      case 'n': break;
      case 'o': if( sarg == "-" ) to_stdout = true;
                else { default_output_filename = sarg; } break;
      case 'q': verbosity = -1; break;
      case 'R': set_mode( program_mode, m_repair ); break;
      case 's': set_mode( program_mode, m_split ); break;
      case 'S': if( arg[0] ) repeated_byte = getnum( arg, 0, 0, 255 );
                set_mode( program_mode, m_nrep_stats ); break;
      case 't': set_mode( program_mode, m_test ); break;
      case 'U': set_mode( program_mode, m_unzcrash ); break;
      case 'v': if( verbosity < 4 ) ++verbosity; break;
      case 'V': show_version(); return 0;
      case 'W': set_mode( program_mode, m_debug_decompress );
                parse_pos_value( arg, bad_byte ); break;
      case 'X': set_mode( program_mode, m_show_packets );
                if( arg[0] ) { parse_pos_value( arg, bad_byte ); } break;
      case 'Y': set_mode( program_mode, m_debug_delay );
                parse_range( arg, range ); break;
      case 'Z': set_mode( program_mode, m_debug_repair );
                parse_pos_value( arg, bad_byte ); break;
      case opt_du: set_mode( program_mode, m_dump );
                   member_list.parse( arg ); break;
      case opt_lt: loose_trailing = true; break;
      case opt_lzl: lzip_level = parse_lzip_level( arg ); break;
      case opt_lzn: lzip_name = arg; break;
      case opt_ref: reference_filename = arg; break;
      case opt_re: set_mode( program_mode, m_remove );
                   member_list.parse( arg ); break;
      case opt_st: set_mode( program_mode, m_strip );
                   member_list.parse( arg ); break;
      default : internal_error( "uncaught option." );
      }
    } // end process options

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

  if( program_mode == m_none )
    {
    show_error( "You must specify the operation to be performed.", 0, true );
    return 1;
    }

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

  const char terminator = isatty( STDOUT_FILENO ) ? '\r' : '\n';
  try {
  switch( program_mode )
    {
    case m_none: internal_error( "invalid operation." ); break;
    case m_alone_to_lz: break;
    case m_debug_decompress:
      one_file( filenames.size() );
      return debug_decompress( filenames[0], bad_byte, false );
    case m_debug_delay:
      one_file( filenames.size() );
      return debug_delay( filenames[0], range, terminator );
    case m_debug_repair:
      one_file( filenames.size() );
      return debug_repair( filenames[0], bad_byte, terminator );
    case m_decompress: break;
    case m_dump:
    case m_strip:
      if( filenames.size() < 1 )
        { show_error( "You must specify at least 1 file.", 0, true ); return 1; }
      return dump_members( filenames, default_output_filename, member_list,
                           force, ignore_errors, ignore_trailing,
                           loose_trailing, program_mode == m_strip, to_stdout );
    case m_list: break;
    case m_md5sum: break;
    case m_merge:
      if( filenames.size() < 2 )
        { show_error( "You must specify at least 2 files.", 0, true ); return 1; }
      return merge_files( filenames, default_output_filename, terminator, force );
    case m_nrep_stats: return print_nrep_stats( filenames, repeated_byte,
                              ignore_errors, ignore_trailing, loose_trailing );
    case m_range_dec:
      one_file( filenames.size() );
      return range_decompress( filenames[0], default_output_filename, range,
                               force, ignore_errors, ignore_trailing,
                               loose_trailing, to_stdout );
    case m_remove:
      if( filenames.size() < 1 )
        { show_error( "You must specify at least 1 file.", 0, true ); return 1; }
      return remove_members( filenames, member_list, ignore_errors,
                             ignore_trailing, loose_trailing );
    case m_repair:
      one_file( filenames.size() );
      return repair_file( filenames[0], default_output_filename, terminator, force );
    case m_reproduce:
      one_file( filenames.size() );
      if( !reference_filename || !reference_filename[0] )
        { show_error( "You must specify a reference file.", 0, true ); return 1; }
      if( range.size() > 0 )
        return debug_reproduce_file( filenames[0], lzip_name,
          reference_filename, range, sector_size, lzip_level );
      else
        return reproduce_file( filenames[0], default_output_filename,
          lzip_name, reference_filename, lzip_level, terminator, force );
    case m_show_packets:
      one_file( filenames.size() );
      return debug_decompress( filenames[0], bad_byte, true );
    case m_split:
      one_file( filenames.size() );
      return split_file( filenames[0], default_output_filename, force );
    case m_test: break;
    case m_unzcrash:
      one_file( filenames.size() );
      return lunzcrash( filenames[0] );
    }
    }
  catch( std::bad_alloc & ) { show_error( mem_msg ); cleanup_and_fail( 1 ); }
  catch( Error & e ) { show_error( e.msg, errno ); cleanup_and_fail( 1 ); }

  if( filenames.empty() ) filenames.push_back("-");

  if( program_mode == m_list )
    return list_files( filenames, ignore_errors, ignore_trailing, loose_trailing );
  if( program_mode == m_md5sum )
    return md5sum_files( filenames );

  if( program_mode != m_alone_to_lz && program_mode != m_decompress &&
      program_mode != m_test )
    internal_error( "invalid decompressor operation." );

  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
      {
      input_filename = filenames[i];
      infd = open_instream( input_filename.c_str(), &in_stats, one_to_one );
      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_alone_to_lz ) set_a_outname( input_filename );
        else set_d_outname( input_filename, extension_index( input_filename ) );
        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
      {
      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 unsigned long long cfile_size =
      ( input_filename.size() && S_ISREG( in_stats.st_mode ) ) ?
        ( in_stats.st_size + 99 ) / 100 : 0;
    int tmp;
    try {
      if( program_mode == m_alone_to_lz )
        tmp = alone_to_lz( infd, pp );
      else
        tmp = decompress( cfile_size, infd, pp, ignore_errors, ignore_trailing,
                          loose_trailing, program_mode == m_test );
      }
    catch( std::bad_alloc & ) { pp( mem_msg ); tmp = 1; }
    catch( Error & e ) { pp(); show_error( e.msg, errno ); tmp = 1; }
    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 &&
        ( program_mode != m_decompress || !ignore_errors ) )
      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;
  }