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/* Copy modification date, access date, permissions and owner from the
   source to destination file.  We have to copy this meta-info off
   into fileMetaInfo before starting to compress / decompress it,
   because doing it afterwards means we get the wrong access time.

   To complicate matters, in compress() and decompress() below, the
   sequence of tests preceding the call to saveInputFileMetaInfo()
   involves calling fileExists(), which in turn establishes its result
   by attempting to fopen() the file, and if successful, immediately
   fclose()ing it again.  So we have to assume that the fopen() call
   does not cause the access time field to be updated.

   Reading of the man page for stat() (man 2 stat) on RedHat 7.2 seems
   to imply that merely doing open() will not affect the access time.
   Therefore we merely need to hope that the C library only does
   open() as a result of fopen(), and not any kind of read()-ahead
   cleverness.

   It sounds pretty fragile to me.  Whether this carries across
   robustly to arbitrary Unix-like platforms (or even works robustly
   on this one, RedHat 7.2) is unknown to me.  Nevertheless ...  
*/
#if BZ_UNIX
static 
struct MY_STAT fileMetaInfo;
#endif

static 
void saveInputFileMetaInfo ( Char *srcName )
{
#  if BZ_UNIX
   IntNative retVal;
   /* Note use of stat here, not lstat. */
   retVal = MY_STAT( srcName, &fileMetaInfo );
   ERROR_IF_NOT_ZERO ( retVal );
#  endif
}


static 
void applySavedTimeInfoToOutputFile ( Char *dstName )
{
#  if BZ_UNIX
   IntNative      retVal;
   struct utimbuf uTimBuf;

   uTimBuf.actime = fileMetaInfo.st_atime;
   uTimBuf.modtime = fileMetaInfo.st_mtime;

   retVal = utime ( dstName, &uTimBuf );
   ERROR_IF_NOT_ZERO ( retVal );
#  endif
}

static 
void applySavedFileAttrToOutputFile ( IntNative fd )
{
#  if BZ_UNIX
   IntNative retVal;

   retVal = fchmod ( fd, fileMetaInfo.st_mode );
   ERROR_IF_NOT_ZERO ( retVal );

   (void) fchown ( fd, fileMetaInfo.st_uid, fileMetaInfo.st_gid );
   /* chown() will in many cases return with EPERM, which can
      be safely ignored.
   */
#  endif
}


/*---------------------------------------------*/
static 
Bool containsDubiousChars ( Char* name )
{
#  if BZ_UNIX
   /* On unix, files can contain any characters and the file expansion
    * is performed by the shell.
    */
   return False;
#  else /* ! BZ_UNIX */
   /* On non-unix (Win* platforms), wildcard characters are not allowed in 
    * filenames.
    */
   for (; *name != '\0'; name++)
      if (*name == '?' || *name == '*') return True;
   return False;
#  endif /* BZ_UNIX */
}


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

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

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