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-rw-r--r--lziprecover.cc161
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];