main-c.c

用c++实现文件的压缩

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "bitio.h"
#include "errhand.h"
#include "main.h"
#include "bitio.c"
#include "errhand.c"
#include "lzw15v.c"


void usage_exit( char * prog_name );
void print_ratios( char * input,char * output );
long file_size( char * name );


int main( int argc,char * argv[] )
{
  BIT_FILE  * output;
  FILE * input;

  setbuf( stdout,NULL );
  if( argc<3 )  usage_exit( argv[0] );
  input=fopen( argv[1],"r" );
  if( input==NULL )
      fatal_error( "Error opening %s for input!\n",argv[1] );
  output=OpenOutputBitFile( argv[2] );
  if( output==NULL )
      fatal_error( "Error oprning %s for output!\n",argv[2] );
  printf( "\nCompressing %s to %s\n",argv[1],argv[2] );
  printf( "Using %s\n",CompressionName );
  CompressFile( input,output,argc-3,argv+3 );
  CloseOutputBitFile( output );
  fclose( input );
  print_ratios( argv[1],argv[2] );
  return( 0 );
}

void usage_exit( char * prog_name )
{
  char * short_name;
  char * extension;

  short_name=strrchr( prog_name,'\\' );
  if( short_name==NULL )
      short_name=strrchr( prog_name,'/' );
  if( short_name==NULL )
      short_name=strrchr( prog_name,'.' );
  if( short_name!=NULL )
      short_name++;
  else
      short_name=prog_name;
  extension=strrchr( short_name,'.' );
  if( extension!=NULL )
      * extension='\0';
  printf( "\nUsage: %s %s\n",short_name,Usage );
  exit( 0 );
}

#ifndef SEEK_END
#define SEEK_END 2
#endif

long file_size( char * name )
{
  long eof_ftell;
  FILE * file;

  file=fopen( name,"r" );
  if( file==NULL )
      return( 0l );
  fseek( file,0l,SEEK_END );
  eof_ftell=ftell( file );
  fclose( file );
  return( eof_ftell );
}

void print_ratios( char * input,char * output )
{
  long input_size;
  long output_size;
  int ratio;

  input_size=file_size( input );
  if( input_size==0 )
      input_size=1;
  output_size=file_size( output );
  ratio=100-( int )( output_size * 100l/input_size );
  printf( "\nInput bytes:   %ld\n",input_size );
  printf( "Output bytes:   %ld\n",output_size );
  if( output_size==0 )
      output_size=1;
  printf( "Compression ratio: %d%%\n",ratio );
}