diff options
Diffstat (limited to '')
| -rw-r--r-- | lziprecover.cc | 161 |
1 files changed, 77 insertions, 84 deletions
diff --git a/lziprecover.cc b/lziprecover.cc index dda4b5e..3acd46c 100644 --- a/lziprecover.cc +++ b/lziprecover.cc @@ -45,6 +45,12 @@ const char * const Program_name = "Lziprecover"; const char * const program_name = "lziprecover"; const char * const program_year = "2010"; +#ifdef O_BINARY +const int o_binary = O_BINARY; +#else +const int o_binary = 0; +#endif + void show_help() throw() { @@ -75,8 +81,8 @@ void show_version() throw() int open_instream( const std::string & input_filename ) throw() { - int ides = open( input_filename.c_str(), O_RDONLY ); - if( ides < 0 ) + int infd = open( input_filename.c_str(), O_RDONLY | o_binary ); + if( infd < 0 ) { if( verbosity >= 0 ) std::fprintf( stderr, "%s: Can't open input file `%s': %s.\n", @@ -85,30 +91,32 @@ int open_instream( const std::string & input_filename ) throw() else { struct stat in_stats; - const int i = fstat( ides, &in_stats ); + const int i = fstat( infd, &in_stats ); if( i < 0 || !S_ISREG( in_stats.st_mode ) ) { if( verbosity >= 0 ) std::fprintf( stderr, "%s: input file `%s' is not a regular file.\n", program_name, input_filename.c_str() ); - close( ides ); - ides = -1; + close( infd ); + infd = -1; } } - return ides; + return infd; } int open_outstream( const std::string & output_filename ) throw() { - int odes = open( output_filename.c_str(), O_CREAT | O_TRUNC | O_WRONLY, S_IRUSR | S_IWUSR ); - if( odes < 0 ) + int outfd = open( output_filename.c_str(), + O_CREAT | O_TRUNC | O_WRONLY | o_binary, + S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH ); + if( outfd < 0 ) { if( verbosity >= 0 ) std::fprintf( stderr, "%s: Can't create output file `%s': %s.\n", program_name, output_filename.c_str(), std::strerror( errno ) ); } - return odes; + return outfd; } @@ -123,44 +131,26 @@ bool next_filename( std::string & output_filename ) } -int search_header( const uint8_t * buffer, const int size, const int pos, - const long long last_header_pos, - const long long partial_file_pos ) - { - for( int i = pos; i < size; ++i ) - if( buffer[i] == magic_string[0] && buffer[i+1] == magic_string[1] && - buffer[i+2] == magic_string[2] && buffer[i+3] == magic_string[3] ) - { - File_trailer trailer; - for( unsigned int j = 0; j < sizeof trailer; ++j ) - ((uint8_t *)&trailer)[j] = buffer[i-(sizeof trailer)+j]; - if( partial_file_pos + i - trailer.member_size() == last_header_pos ) - return i; - } - return -1; - } - - -bool verify_header( const uint8_t * buffer, const int pos ) +bool verify_header( const uint8_t * const buffer, const int pos ) { File_header header; - for( unsigned int i = 0; i < sizeof header; ++i ) - ((uint8_t *)&header)[i] = buffer[pos+i]; + for( int i = 0; i < File_header::size; ++i ) + header.data[i] = buffer[pos+i]; if( !header.verify_magic() ) { - show_error( "bad magic number (file not created by lzip).\n" ); + show_error( "bad magic number (file not in lzip format).\n" ); return false; } - if( header.version == 0 ) + if( header.version() == 0 ) { show_error( "version 0 member format can't be recovered.\n" ); return false; } - if( header.version != 1 ) + if( header.version() != 1 ) { if( verbosity >= 0 ) std::fprintf( stderr, "version %d member format not supported, newer %s needed.\n", - header.version, program_name ); + header.version(), program_name ); return false; } return true; @@ -169,16 +159,16 @@ bool verify_header( const uint8_t * buffer, const int pos ) int process_file( const std::string & input_filename, uint8_t * & base_buffer ) { - const int hsize = sizeof( File_header ); - const int tsize = sizeof( File_trailer ); + const int hsize = File_header::size; + const int tsize = File_trailer::size(); const int buffer_size = 65536; const int base_buffer_size = tsize + buffer_size + hsize; base_buffer = new uint8_t[base_buffer_size]; uint8_t * const buffer = base_buffer + tsize; - const int inhandle = open_instream( input_filename ); - if( inhandle < 0 ) return 1; - int size = readblock( inhandle, (char *)buffer, buffer_size + hsize ) - hsize; + const int infd = open_instream( input_filename ); + if( infd < 0 ) return 1; + int size = readblock( infd, buffer, buffer_size + hsize ) - hsize; bool at_stream_end = ( size < buffer_size ); if( size != buffer_size && errno ) { show_error( "read error", errno ); return 1; } @@ -187,57 +177,60 @@ int process_file( const std::string & input_filename, uint8_t * & base_buffer ) if( !verify_header( buffer, 0 ) ) return 2; std::string output_filename( "rec00001" ); output_filename += input_filename; - int outhandle = open_outstream( output_filename ); - if( outhandle < 0 ) { close( inhandle ); return 1; } + int outfd = open_outstream( output_filename ); + if( outfd < 0 ) { close( infd ); return 1; } - long long last_header_pos = 0; - long long partial_file_pos = 0; - int pos = 0; - while( size > 0 ) + long long partial_member_size = 0; + while( true ) { - const int newpos = search_header( buffer, size - hsize, pos + hsize, - last_header_pos, partial_file_pos ); - if( newpos > pos ) + int pos = 0; + for( int newpos = 1; newpos <= size; ++newpos ) + if( buffer[newpos] == magic_string[0] && + buffer[newpos+1] == magic_string[1] && + buffer[newpos+2] == magic_string[2] && + buffer[newpos+3] == magic_string[3] ) + { + long long member_size = 0; + for( int i = 1; i <= 8; ++i ) + { member_size <<= 8; member_size += base_buffer[tsize+newpos-i]; } + if( partial_member_size + newpos - pos == member_size ) + { // header found + const int wr = writeblock( outfd, buffer + pos, newpos - pos ); + if( wr != newpos - pos ) + { show_error( "write error", errno ); return 1; } + if( close( outfd ) != 0 ) + { show_error( "error closing output file", errno ); return 1; } + if( !next_filename( output_filename ) ) + { show_error( "too many members in file" ); close( infd ); return 1; } + outfd = open_outstream( output_filename ); + if( outfd < 0 ) { close( infd ); return 1; } + partial_member_size = 0; + pos = newpos; + } + } + + if( at_stream_end ) { - const int wr = writeblock( outhandle, (char *)buffer + pos, newpos - pos ); - if( wr != newpos - pos ) + const int wr = writeblock( outfd, buffer + pos, size + hsize - pos ); + if( wr != size + hsize - pos ) { show_error( "write error", errno ); return 1; } - if( close( outhandle ) != 0 ) - { show_error( "error closing output file", errno ); return 1; } - if( !next_filename( output_filename ) ) - { show_error( "too many members in file" ); close( inhandle ); return 1; } - outhandle = open_outstream( output_filename ); - if( outhandle < 0 ) { close( inhandle ); return 1; } - last_header_pos = partial_file_pos + newpos; - pos = newpos; - continue; + break; } - else + if( pos < buffer_size ) { - if( !at_stream_end ) - { - partial_file_pos += buffer_size; - const int wr = writeblock( outhandle, (char *)buffer + pos, buffer_size - pos ); - if( wr != buffer_size - pos ) - { show_error( "write error", errno ); return 1; } - std::memcpy( base_buffer, base_buffer + buffer_size, tsize + hsize ); - pos = 0; - } - else - { - const int wr = writeblock( outhandle, (char *)buffer + pos, size + hsize - pos ); - if( wr != size + hsize - pos ) - { show_error( "write error", errno ); return 1; } - break; - } + partial_member_size += buffer_size - pos; + const int wr = writeblock( outfd, buffer + pos, buffer_size - pos ); + if( wr != buffer_size - pos ) + { show_error( "write error", errno ); return 1; } } - size = readblock( inhandle, (char *)buffer + hsize, buffer_size ); + std::memcpy( base_buffer, base_buffer + buffer_size, tsize + hsize ); + size = readblock( infd, buffer + hsize, buffer_size ); at_stream_end = ( size < buffer_size ); if( size != buffer_size && errno ) { show_error( "read error", errno ); return 1; } } - close( inhandle ); - if( close( outhandle ) != 0 ) + close( infd ); + if( close( outfd ) != 0 ) { show_error( "error closing output file", errno ); return 1; } return 0; } @@ -248,7 +241,7 @@ int process_file( const std::string & input_filename, uint8_t * & base_buffer ) int verbosity = 0; -void show_error( const char * msg, const int errcode, const bool help ) throw() +void show_error( const char * const msg, const int errcode, const bool help ) throw() { if( verbosity >= 0 ) { @@ -264,7 +257,7 @@ void show_error( const char * msg, const int errcode, const bool help ) throw() } -void internal_error( const char * msg ) +void internal_error( const char * const msg ) { std::string s( "internal error: " ); s += msg; show_error( s.c_str() ); @@ -275,7 +268,7 @@ void internal_error( const char * msg ) // Returns the number of bytes really read. // If (returned value < size) and (errno == 0), means EOF was reached. // -int readblock( const int fd, char * buf, const int size ) throw() +int readblock( const int fd, uint8_t * const buf, const int size ) throw() { int rest = size; errno = 0; @@ -294,7 +287,7 @@ int readblock( const int fd, char * buf, const int size ) throw() // Returns the number of bytes really written. // If (returned value < size), it is always an error. // -int writeblock( const int fd, const char * buf, const int size ) throw() +int writeblock( const int fd, const uint8_t * const buf, const int size ) throw() { int rest = size; errno = 0; @@ -309,7 +302,7 @@ int writeblock( const int fd, const char * buf, const int size ) throw() } -int main( const int argc, const char * argv[] ) +int main( const int argc, const char * const argv[] ) { invocation_name = argv[0]; |