campo-sirio/al/examples/ex24con.cpp

//
// EX24CON.CPP
//
//  C++/DOS Example program for ArchiveLib 2.0
//
//  Copyright (c) Greenleaf Software, Inc. 1994 - 1996
//  All Rights Reserved
//
// MEMBERS/FUNCTIONS DEMONSTRATED
//
//   ALCompressedObject::Extract()
//   ALCompressedOjbect::Insert()
//
// DESCRIPTION
//
//  This example gives a quick demo on how to insert and extract
//  files from an ALCompressedObject.  It provides a command line interfac
//  that makes it easy to test the functions to insert and extract files
//  from an ALCompressedObject.  Remember that if you create a compressed
//  object of your own, and you want to test it with this program,
//  you will have to make sure your compression engine has the same
//  parameters as the one used here.  Modify this program to match whatever
//  you have used to create the objects.
//
// REVISION HISTORY
//
//  February 1, 1996  2.0A  : Second release
//

#include <stdio.h>
#include <conio.h>
#include <iostream.h>

#include "al.h"

//
// Global guys, easier to create them here just one time than have to
// create them in each of the three subroutines.
//

#if defined( ZIP )
ALPkCompressor Compressor;
ALPkDecompressor Decompressor;
#else
ALGlCompressor Compressor( AL_GREENLEAF_LEVEL_4 );
ALGlDecompressor Decompressor( AL_GREENLEAF_LEVEL_4 );
#endif
ALSpinner monitor( AL_MONITOR_OBJECTS );

//
// Prototypes for the three command handlers.
//
int test( char *object_name );
int insert( char *object_name, char *file_name );
int extract( char *object_name, char *file_name );

//
// main() just has to parse the command line and then pick the appropriate
// routine to call.  If the command line looks bogus we print out the
// usage information and exit.
//
int main( int argc, char *argv[] )
{
    cout << "Archive Library 2.0\nEX24CON.CPP\n\n";
    cout << "This example gives a quick demo on how to insert and extract\n";
    cout << "files from an ALCompressedObject.  It provides a command line interface\n";
    cout << "that makes it easy to test the functions to insert and extract files\n";
    cout << "from an ALCompressedObject.  Remember that if you create a compressed\n";
    cout << "object of your own, and you want to test it with this program,\n";
    cout << "you will have to make sure your compression engine has the same\n";
    cout << "parameters as the one used here.  Modify this program to match whatever\n";
    cout << "you have used to create the objects.\n";
    getch();

    if ( argc == 3 && strcmp( argv[ 1 ], "-t" ) == 0 )
        return test( argv[ 2 ] );
    else if ( argc == 4 && strcmp( argv[ 1 ], "-i" ) == 0 )
        return insert( argv[ 2 ], argv[ 3 ] );
    else if ( argc == 4 && strcmp( argv[ 1 ], "-x" ) == 0 )
        return extract( argv[ 2 ], argv[ 3 ] );
    cout << "\n"
         << "Usage: EX24CON -t | -i | -x compressed_file [plain_file]\n"
         << "\n"
         << "Options:  -t : Test the object\n"
         << "          -i : Insert a file into the object\n"
         << "          -x : Extract a file from the object\n"
         << "\n"
         << "This example program can be used to insert or extract\n"
         << "files from a compressed object.  It will always use the\n"
         << "Greenleaf compression engine at level 4.\n"
         << "\n";
    return 1;
}

//
// This subroutine is called when the program is executed with the -t
// option.  It extracts the compressed file out of the compressed object,
// then prints out the CRC and length so you can compare them to the
// CRC and length in the compressed object.  It then deletes the
// temporary file and exits.
//
// Note that getting the information out of the compressed object is
// done using hardcoded reads from specific locations.
//

int test( char *object_name )
{
    int status;
    ALFile object_file( object_name );
    ALCompressedObject object( object_file, &Compressor, &Decompressor );
    ALFile file( "" );
    file.mpMonitor = &monitor;
    monitor.mlObjectStart = 0;
    status = object.Extract( file );
    file.Delete();
    cout << "Status: " << object.mStatus.GetStatusDetail() << "\n";
    cout << "Extracted file has length: " << file.GetSize() << "\n";
    cout << "Extracted file has CRC: " << hex << file.GetCrc32() << "\n";
    object_file.Open();
    long uncompressed_size;
    long compressed_size;
    long crc_32;
    object_file.ReadGlLong( uncompressed_size );
    cout << dec
         << "Compressed object indicates an uncompressed size of "
         << uncompressed_size
         << "\n";
    object_file.ReadGlLong( compressed_size );
    cout << "Compressed object indicates a compressed size of "
         << compressed_size
         << "\n";
    object_file.ReadGlLong( crc_32 );
    cout << hex
         << "Compressed object indicates an CRC of "
         << ~crc_32
         << "\n";
    return status;
}

//
// This routine is used to insert a file into a compressed object.  Because
// of the way compressed objects work, this is a destructive operation, so
// I ask for permission if the compressed file already exists.  After that
// it is a simple matter to call the Insert() function and then exit.
//

int insert( char *object_name, char *file_name )
{
    int status;
    FILE *p = fopen( object_name, "r" );
    if ( p ) {
        char answer;
        cout << "I don't reall want to clobber file " << object_name << "\n";
        cout << "Should I (Y/N) ? " << flush;
        cin >> answer;
        if ( answer != 'Y' && answer != 'y' )
            return 1;
        fclose( p );
        cout << "It will be clobbered.\n";
    }
    ALFile object_file( object_name );
    ALCompressedObject object( object_file, &Compressor, &Decompressor );
    ALFile file( file_name );
    file.mpMonitor = &monitor;
    monitor.mlObjectStart = 0;
    status = object.Insert( file );
    cout << "Status: " << object.mStatus.GetStatusDetail() << "\n";
    return status;
}

//
// This routine is used to extract a file from a compressed object.  Because
// of the way compressed objects work, this is a destructive operation, so
// I ask for permission if the output file already exists.  After that
// it is a simple matter to call the Extract() function and then exit.
//

int extract( char *object_name, char *file_name )
{
    int status;
    FILE *p = fopen( file_name, "r" );
    if ( p ) {
        char answer;
        cout << "I don't reall want to clobber file " << file_name << "\n";
        cout << "Should I (Y/N) ? " << flush;
        cin >> answer;
        if ( answer != 'Y' && answer != 'y' )
            return 1;
        fclose( p );
        cout << "It will be clobbered.\n";
    }
    ALFile object_file( object_name );
    ALCompressedObject object( object_file, &Compressor, &Decompressor );
    ALFile file( file_name );
    file.mpMonitor = &monitor;
    monitor.mlObjectStart = 0;
    status = object.Extract( file );
    cout << "Status: " << object.mStatus.GetStatusDetail() << "\n";
    return status;
}