bzip2.c

ReactOS是一些高手根据Windows XP的内核编写出的类XP。内核实现机理和API函数调用几乎相同。甚至可以兼容XP的程序。喜欢研究系统内核的人可以看一看。

{
   fprintf ( stderr,
             "bzip2: I'm not configured correctly for this platform!\n"
             "\tI require Int32, Int16 and Char to have sizes\n"
             "\tof 4, 2 and 1 bytes to run properly, and they don't.\n"
             "\tProbably you can fix this by defining them correctly,\n"
             "\tand recompiling.  Bye!\n" );
   setExit(3);
   exit(exitValue);
}


/*---------------------------------------------------*/
/*--- The main driver machinery                   ---*/
/*---------------------------------------------------*/

/*---------------------------------------------*/
static
void pad ( Char *s )
{
   Int32 i;
   if ( (Int32)strlen(s) >= longestFileName ) return;
   for (i = 1; i <= longestFileName - (Int32)strlen(s); i++)
      fprintf ( stderr, " " );
}


/*---------------------------------------------*/
static
void copyFileName ( Char* to, Char* from )
{
   if ( strlen(from) > FILE_NAME_LEN-10 )  {
      fprintf (
         stderr,
         "bzip2: file name\n`%s'\n"
         "is suspiciously (more than %d chars) long.\n"
         "Try using a reasonable file name instead.  Sorry! :-)\n",
         from, FILE_NAME_LEN-10
      );
      setExit(1);
      exit(exitValue);
   }

  strncpy(to,from,FILE_NAME_LEN-10);
  to[FILE_NAME_LEN-10]='\0';
}


/*---------------------------------------------*/
static
Bool fileExists ( Char* name )
{
   FILE *tmp   = fopen ( name, "rb" );
   Bool exists = (tmp != NULL);
   if (tmp != NULL) fclose ( tmp );
   return exists;
}


/*---------------------------------------------*/
/*--
  if in doubt, return True
--*/
static
Bool notAStandardFile ( Char* name )
{
   IntNative      i;
   struct MY_STAT statBuf;

   i = MY_LSTAT ( name, &statBuf );
   if (i != 0) return True;
   if (MY_S_IFREG(statBuf.st_mode)) return False;
   return True;
}


/*---------------------------------------------*/
/*--
  rac 11/21/98 see if file has hard links to it
--*/
static
Int32 countHardLinks ( Char* name )
{
   IntNative      i;
   struct MY_STAT statBuf;

   i = MY_LSTAT ( name, &statBuf );
   if (i != 0) return 0;
   return (statBuf.st_nlink - 1);
}


/*---------------------------------------------*/
static
void copyDatePermissionsAndOwner ( Char *srcName, Char *dstName )
{
#if BZ_UNIX
   IntNative      retVal;
   struct MY_STAT statBuf;
   struct utimbuf uTimBuf;

   retVal = MY_LSTAT ( srcName, &statBuf );
   ERROR_IF_NOT_ZERO ( retVal );
   uTimBuf.actime = statBuf.st_atime;
   uTimBuf.modtime = statBuf.st_mtime;

   retVal = chmod ( dstName, statBuf.st_mode );
   ERROR_IF_NOT_ZERO ( retVal );

   retVal = utime ( dstName, &uTimBuf );
   ERROR_IF_NOT_ZERO ( retVal );

   retVal = chown ( dstName, statBuf.st_uid, statBuf.st_gid );
   /* chown() will in many cases return with EPERM, which can
      be safely ignored.
   */
#endif
}


/*---------------------------------------------*/
static
void setInterimPermissions ( Char *dstName )
{
#if BZ_UNIX
   IntNative      retVal;
   retVal = chmod ( dstName, S_IRUSR | S_IWUSR );
   ERROR_IF_NOT_ZERO ( retVal );
#endif
}


/*---------------------------------------------*/
static
Bool containsDubiousChars ( Char* name )
{
   Bool cdc = False;
   for (; *name != '\0'; name++)
      if (*name == '?' || *name == '*') cdc = True;
   return cdc;
}


/*---------------------------------------------*/
#define BZ_N_SUFFIX_PAIRS 4

Char* zSuffix[BZ_N_SUFFIX_PAIRS]
   = { ".bz2", ".bz", ".tbz2", ".tbz" };
Char* unzSuffix[BZ_N_SUFFIX_PAIRS]
   = { "", "", ".tar", ".tar" };

static
Bool hasSuffix ( Char* s, Char* suffix )
{
   Int32 ns = strlen(s);
   Int32 nx = strlen(suffix);
   if (ns < nx) return False;
   if (strcmp(s + ns - nx, suffix) == 0) return True;
   return False;
}

static
Bool mapSuffix ( Char* name,
                 Char* oldSuffix, Char* newSuffix )
{
   if (!hasSuffix(name,oldSuffix)) return False;
   name[strlen(name)-strlen(oldSuffix)] = 0;
   strcat ( name, newSuffix );
   return True;
}


/*---------------------------------------------*/
static
void compress ( Char *name )
{
   FILE  *inStr;
   FILE  *outStr;
   Int32 n, i;

   deleteOutputOnInterrupt = False;

   if (name == NULL && srcMode != SM_I2O)
      panic ( "compress: bad modes\n" );

   switch (srcMode) {
      case SM_I2O:
         copyFileName ( inName, "(stdin)" );
         copyFileName ( outName, "(stdout)" );
         break;
      case SM_F2F:
         copyFileName ( inName, name );
         copyFileName ( outName, name );
         strcat ( outName, ".bz2" );
         break;
      case SM_F2O:
         copyFileName ( inName, name );
         copyFileName ( outName, "(stdout)" );
         break;
   }

   if ( srcMode != SM_I2O && containsDubiousChars ( inName ) ) {
      if (noisy)
      fprintf ( stderr, "%s: There are no files matching `%s'.\n",
                progName, inName );
      setExit(1);
      return;
   }
   if ( srcMode != SM_I2O && !fileExists ( inName ) ) {
      fprintf ( stderr, "%s: Can't open input file %s: %s.\n",
                progName, inName, strerror(errno) );
      setExit(1);
      return;
   }
   for (i = 0; i < BZ_N_SUFFIX_PAIRS; i++) {
      if (hasSuffix(inName, zSuffix[i])) {
         if (noisy)
         fprintf ( stderr,
                   "%s: Input file %s already has %s suffix.\n",
                   progName, inName, zSuffix[i] );
         setExit(1);
         return;
      }
   }
   if ( srcMode == SM_F2F && !forceOverwrite && notAStandardFile ( inName )) {
      if (noisy)
      fprintf ( stderr, "%s: Input file %s is not a normal file.\n",
                progName, inName );
      setExit(1);
      return;
   }
   if ( srcMode == SM_F2F && !forceOverwrite && fileExists ( outName ) ) {
      fprintf ( stderr, "%s: Output file %s already exists.\n",
                progName, outName );
      setExit(1);
      return;
   }
   if ( srcMode == SM_F2F && !forceOverwrite &&
        (n=countHardLinks ( inName )) > 0) {
      fprintf ( stderr, "%s: Input file %s has %d other link%s.\n",
                progName, inName, n, n > 1 ? "s" : "" );
      setExit(1);
      return;
   }

   switch ( srcMode ) {

      case SM_I2O:
         inStr = stdin;
         outStr = stdout;
         if ( isatty ( fileno ( stdout ) ) ) {
            fprintf ( stderr,
                      "%s: I won't write compressed data to a terminal.\n",
                      progName );
            fprintf ( stderr, "%s: For help, type: `%s --help'.\n",
                              progName, progName );
            setExit(1);
            return;
         };
         break;

      case SM_F2O:
         inStr = fopen ( inName, "rb" );
         outStr = stdout;
         if ( isatty ( fileno ( stdout ) ) ) {
            fprintf ( stderr,
                      "%s: I won't write compressed data to a terminal.\n",
                      progName );
            fprintf ( stderr, "%s: For help, type: `%s --help'.\n",
                              progName, progName );
            if ( inStr != NULL ) fclose ( inStr );
            setExit(1);
            return;
         };
         if ( inStr == NULL ) {
            fprintf ( stderr, "%s: Can't open input file %s: %s.\n",
                      progName, inName, strerror(errno) );
            setExit(1);
            return;
         };
         break;

      case SM_F2F:
         inStr = fopen ( inName, "rb" );
         outStr = fopen ( outName, "wb" );
         if ( outStr == NULL) {
            fprintf ( stderr, "%s: Can't create output file %s: %s.\n",
                      progName, outName, strerror(errno) );
            if ( inStr != NULL ) fclose ( inStr );
            setExit(1);
            return;
         }
         if ( inStr == NULL ) {
            fprintf ( stderr, "%s: Can't open input file %s: %s.\n",
                      progName, inName, strerror(errno) );
            if ( outStr != NULL ) fclose ( outStr );
            setExit(1);
            return;
         };
         setInterimPermissions ( outName );
         break;

      default:
         panic ( "compress: bad srcMode" );
         break;
   }

   if (verbosity >= 1) {
      fprintf ( stderr,  "  %s: ", inName );
      pad ( inName );
      fflush ( stderr );
   }

   /*--- Now the input and output handles are sane.  Do the Biz. ---*/
   outputHandleJustInCase = outStr;
   deleteOutputOnInterrupt = True;
   compressStream ( inStr, outStr );
   outputHandleJustInCase = NULL;

   /*--- If there was an I/O error, we won't get here. ---*/
   if ( srcMode == SM_F2F ) {
      copyDatePermissionsAndOwner ( inName, outName );
      deleteOutputOnInterrupt = False;
      if ( !keepInputFiles ) {
         IntNative retVal = remove ( inName );
         ERROR_IF_NOT_ZERO ( retVal );
      }
   }

   deleteOutputOnInterrupt = False;
}


/*---------------------------------------------*/
static
void uncompress ( Char *name )
{
   FILE  *inStr;
   FILE  *outStr;
   Int32 n, i;
   Bool  magicNumberOK;
   Bool  cantGuess;

   deleteOutputOnInterrupt = False;

   if (name == NULL && srcMode != SM_I2O)
      panic ( "uncompress: bad modes\n" );

   cantGuess = False;
   switch (srcMode) {
      case SM_I2O:
         copyFileName ( inName, "(stdin)" );
         copyFileName ( outName, "(stdout)" );
         break;
      case SM_F2F:
         copyFileName ( inName, name );
         copyFileName ( outName, name );
         for (i = 0; i < BZ_N_SUFFIX_PAIRS; i++)
            if (mapSuffix(outName,zSuffix[i],unzSuffix[i]))
               goto zzz;
         cantGuess = True;
         strcat ( outName, ".out" );
         break;
      case SM_F2O:
         copyFileName ( inName, name );
         copyFileName ( outName, "(stdout)" );
         break;
   }

   zzz:
   if ( srcMode != SM_I2O && containsDubiousChars ( inName ) ) {
      if (noisy)
      fprintf ( stderr, "%s: There are no files matching `%s'.\n",
                progName, inName );
      setExit(1);
      return;
   }
   if ( srcMode != SM_I2O && !fileExists ( inName ) ) {
      fprintf ( stderr, "%s: Can't open input file %s: %s.\n",
                progName, inName, strerror(errno) );
      setExit(1);
      return;
   }
   if ( srcMode == SM_F2F && !forceOverwrite && notAStandardFile ( inName )) {
      if (noisy)
      fprintf ( stderr, "%s: Input file %s is not a normal file.\n",
                progName, inName );
      setExit(1);
      return;
   }
   if ( /* srcMode == SM_F2F implied && */ cantGuess ) {
      if (noisy)
      fprintf ( stderr,
                "%s: Can't guess original name for %s -- using %s\n",
                progName, inName, outName );
      /* just a warning, no return */
   }
   if ( srcMode == SM_F2F && !forceOverwrite && fileExists ( outName ) ) {
      fprintf ( stderr, "%s: Output file %s already exists.\n",
                progName, outName );
      setExit(1);
      return;
   }
   if ( srcMode == SM_F2F && !forceOverwrite &&
        (n=countHardLinks ( inName ) ) > 0) {
      fprintf ( stderr, "%s: Input file %s has %d other link%s.\n",
                progName, inName, n, n > 1 ? "s" : "" );
      setExit(1);
      return;
   }

   switch ( srcMode ) {

      case SM_I2O:
         inStr = stdin;
         outStr = stdout;
         if ( isatty ( fileno ( stdin ) ) ) {
            fprintf ( stderr,
                      "%s: I won't read compressed data from a terminal.\n",
                      progName );
            fprintf ( stderr, "%s: For help, type: `%s --help'.\n",
                              progName, progName );
            setExit(1);
            return;
         };
         break;

      case SM_F2O:
         inStr = fopen ( inName, "rb" );
         outStr = stdout;
         if ( inStr == NULL ) {
            fprintf ( stderr, "%s: Can't open input file %s:%s.\n",
                      progName, inName, strerror(errno) );
            if ( inStr != NULL ) fclose ( inStr );
            setExit(1);
            return;
         };
         break;

      case SM_F2F:
         inStr = fopen ( inName, "rb" );
         outStr = fopen ( outName, "wb" );
         if ( outStr == NULL) {
            fprintf ( stderr, "%s: Can't create output file %s: %s.\n",
                      progName, outName, strerror(errno) );
            if ( inStr != NULL ) fclose ( inStr );
            setExit(1);
            return;
         }
         if ( inStr == NULL ) {
            fprintf ( stderr, "%s: Can't open input file %s: %s.\n",
                      progName, inName, strerror(errno) );
            if ( outStr != NULL ) fclose ( outStr );
            setExit(1);
            return;
         };
         setInterimPermissions ( outName );
         break;

      default:
         panic ( "uncompress: bad srcMode" );
         break;
   }

   if (verbosity >= 1) {
      fprintf ( stderr, "  %s: ", inName );
      pad ( inName );
      fflush ( stderr );
   }

   /*--- Now the input and output handles are sane.  Do the Biz. ---*/
   outputHandleJustInCase = outStr;
   deleteOutputOnInterrupt = True;
   magicNumberOK = uncompressStream ( inStr, outStr );
   outputHandleJustInCase = NULL;

   /*--- If there was an I/O error, we won't get here. ---*/
   if ( magicNumberOK ) {
      if ( srcMode == SM_F2F ) {
         copyDatePermissionsAndOwner ( inName, outName );
         deleteOutputOnInterrupt = False;
         if ( !keepInputFiles ) {
            IntNative retVal = remove ( inName );
            ERROR_IF_NOT_ZERO ( retVal );
         }
      }
   } else {
      unzFailsExist = True;
      deleteOutputOnInterrupt = False;
      if ( srcMode == SM_F2F ) {
         IntNative retVal = remove ( outName );
         ERROR_IF_NOT_ZERO ( retVal );
      }
   }
   deleteOutputOnInterrupt = False;

   if ( magicNumberOK ) {
      if (verbosity >= 1)
         fprintf ( stderr, "done\n" );
   } else {
      setExit(2);
      if (verbosity >= 1)
         fprintf ( stderr, "not a bzip2 file.\n" ); else
         fprintf ( stderr,
                   "%s: %s is not a bzip2 file.\n",
                   progName, inName );
   }

}


/*---------------------------------------------*/