os2zip.c

压缩算法的源代码

/*
 * @(#)dir.c 1.4 87/11/06 Public Domain.
 *
 *  A public domain implementation of BSD directory routines for
 *  MS-DOS.  Written by Michael Rendell ({uunet,utai}michael@garfield),
 *  August 1897
 *  Ported to OS/2 by Kai Uwe Rommel
 *  December 1989, February 1990
 *  Change for HPFS support, October 1990
 */

/* does also contain EA access code for use in ZIP */


#ifdef __EMX__
#define __32BIT__
#endif

#include "zip.h"

#include <stdlib.h>
#include <time.h>
#include <ctype.h>

#ifdef __WATCOMC__
#include <malloc.h>
unsigned char __near _osmode = OS2_MODE;
#endif

#define INCL_NOPM
#define INCL_DOSNLS
#define INCL_DOSERRORS
#include <os2.h>

#include "os2zip.h"


#define EAID     0x0009


#ifdef __32BIT__
#define DosFindFirst(p1, p2, p3, p4, p5, p6) \
        DosFindFirst(p1, p2, p3, p4, p5, p6, 1)
#else
#define DosQueryCurrentDisk DosQCurDisk
#define DosQueryFSAttach(p1, p2, p3, p4, p5) \
        DosQFSAttach(p1, p2, p3, p4, p5, 0)
#define DosQueryPathInfo(p1, p2, p3, p4) \
        DosQPathInfo(p1, p2, p3, p4, 0)
#define DosSetPathInfo(p1, p2, p3, p4, p5) \
        DosSetPathInfo(p1, p2, p3, p4, p5, 0)
#define DosEnumAttribute(p1, p2, p3, p4, p5, p6, p7) \
        DosEnumAttribute(p1, p2, p3, p4, p5, p6, p7, 0)
#define DosFindFirst(p1, p2, p3, p4, p5, p6) \
        DosFindFirst(p1, p2, p3, p4, p5, p6, 0)
#define DosMapCase DosCaseMap
#endif


#ifndef UTIL

extern int noisy;

#ifndef S_IFMT
#define S_IFMT 0xF000
#endif

static int attributes = A_DIR | A_HIDDEN | A_SYSTEM;

static char *getdirent(char *);
static void free_dircontents(struct _dircontents *);

#ifdef __32BIT__
static HDIR hdir;
static ULONG count;
static FILEFINDBUF3 find;
#else
static HDIR hdir;
static USHORT count;
static FILEFINDBUF find;
#endif


DIR *opendir(char *name)
{
  struct stat statb;
  DIR *dirp;
  char c;
  char *s;
  struct _dircontents *dp;
  char nbuf[MAXPATHLEN + 1];
  int len;

  strcpy(nbuf, name);
  len = strlen (nbuf);
  s = nbuf + len;

  if ( ((c = nbuf[strlen(nbuf) - 1]) == '\\' || c == '/') &&
       (strlen(nbuf) > 1) )
  {
    nbuf[strlen(nbuf) - 1] = 0;

    if ( nbuf[strlen(nbuf) - 1] == ':' )
      strcat(nbuf, "\\.");
  }
  else
    if ( nbuf[strlen(nbuf) - 1] == ':' )
      strcat(nbuf, ".");

  if (stat(nbuf, &statb) < 0 || (statb.st_mode & S_IFMT) != S_IFDIR)
    return NULL;

  if ( (dirp = malloc(sizeof(DIR))) == NULL )
    return NULL;

  if ( nbuf[strlen(nbuf) - 1] == '.' )
    strcpy(nbuf + strlen(nbuf) - 1, "*.*");
  else
    if ( ((c = nbuf[strlen(nbuf) - 1]) == '\\' || c == '/') &&
         (strlen(nbuf) == 1) )
      strcat(nbuf, "*.*");
    else
      strcat(nbuf, "\\*.*");

  dirp -> dd_loc = 0;
  dirp -> dd_contents = dirp -> dd_cp = NULL;

  if ((s = getdirent(nbuf)) == NULL)
    return dirp;

  do
  {
    if (((dp = malloc(sizeof(struct _dircontents))) == NULL) ||
        ((dp -> _d_entry = malloc(strlen(s) + 1)) == NULL)      )
    {
      if (dp)
        free(dp);
      free_dircontents(dirp -> dd_contents);

      return NULL;
    }

    if (dirp -> dd_contents)
    {
      dirp -> dd_cp -> _d_next = dp;
      dirp -> dd_cp = dirp -> dd_cp -> _d_next;
    }
    else
      dirp -> dd_contents = dirp -> dd_cp = dp;

    strcpy(dp -> _d_entry, s);
    dp -> _d_next = NULL;

    dp -> _d_size = find.cbFile;
    dp -> _d_mode = find.attrFile;
    dp -> _d_time = *(unsigned *) &(find.ftimeLastWrite);
    dp -> _d_date = *(unsigned *) &(find.fdateLastWrite);
  }
  while ((s = getdirent(NULL)) != NULL);

  dirp -> dd_cp = dirp -> dd_contents;

  return dirp;
}


void closedir(DIR * dirp)
{
  free_dircontents(dirp -> dd_contents);
  free(dirp);
}


struct direct *readdir(DIR * dirp)
{
  static struct direct dp;

  if (dirp -> dd_cp == NULL)
    return NULL;

  dp.d_namlen = dp.d_reclen =
    strlen(strcpy(dp.d_name, dirp -> dd_cp -> _d_entry));

  dp.d_ino = 0;

  dp.d_size = dirp -> dd_cp -> _d_size;
  dp.d_mode = dirp -> dd_cp -> _d_mode;
  dp.d_time = dirp -> dd_cp -> _d_time;
  dp.d_date = dirp -> dd_cp -> _d_date;

  dirp -> dd_cp = dirp -> dd_cp -> _d_next;
  dirp -> dd_loc++;

  return &dp;
}


void seekdir(DIR * dirp, long off)
{
  long i = off;
  struct _dircontents *dp;

  if (off >= 0)
  {
    for (dp = dirp -> dd_contents; --i >= 0 && dp; dp = dp -> _d_next);

    dirp -> dd_loc = off - (i + 1);
    dirp -> dd_cp = dp;
  }
}


long telldir(DIR * dirp)
{
  return dirp -> dd_loc;
}


static void free_dircontents(struct _dircontents * dp)
{
  struct _dircontents *odp;

  while (dp)
  {
    if (dp -> _d_entry)
      free(dp -> _d_entry);

    dp = (odp = dp) -> _d_next;
    free(odp);
  }
}


static char *getdirent(char *dir)
{
  int done;
  static int lower;

  if (dir != NULL)
  {                                    /* get first entry */
    hdir = HDIR_CREATE;
    count = 1;
    done = DosFindFirst(dir, &hdir, attributes, &find, sizeof(find), &count);
    lower = IsFileSystemFAT(dir);
  }
  else                                 /* get next entry */
    done = DosFindNext(hdir, &find, sizeof(find), &count);

  if (done == 0)
  {
    if ( lower )
      StringLower(find.achName);
    return find.achName;
  }
  else
  {
    DosFindClose(hdir);
    return NULL;
  }
}


/* FAT / HPFS detection */

int IsFileSystemFAT(char *dir)
{
  static USHORT nLastDrive = -1, nResult;
  ULONG lMap;
  BYTE bData[64], bName[3];
#ifdef __32BIT__
  ULONG nDrive, cbData;
  PFSQBUFFER2 pData = (PFSQBUFFER2) bData;
#else
  USHORT nDrive, cbData;
  PFSQBUFFER pData = (PFSQBUFFER) bData;
#endif

  if ( _osmode == DOS_MODE )
    return TRUE;
  else
  {
    /* We separate FAT and HPFS+other file systems here.
       at the moment I consider other systems to be similar to HPFS,
       i.e. support long file names and beeing case sensitive */

    if ( isalpha(dir[0]) && (dir[1] == ':') )
      nDrive = to_up(dir[0]) - '@';
    else
      DosQueryCurrentDisk(&nDrive, &lMap);

    if ( nDrive == nLastDrive )
      return nResult;

    bName[0] = (char) (nDrive + '@');
    bName[1] = ':';
    bName[2] = 0;

    nLastDrive = nDrive;
    cbData = sizeof(bData);

    if ( !DosQueryFSAttach(bName, 0, FSAIL_QUERYNAME, (PVOID) pData, &cbData) )
      nResult = !strcmp(pData -> szFSDName + pData -> cbName, "FAT");
    else
      nResult = FALSE;

    /* End of this ugly code */
    return nResult;
  }
}


/* access mode bits and time stamp */

int GetFileMode(char *name)
{
#ifdef __32BIT__
  FILESTATUS3 fs;
  return DosQueryPathInfo(name, 1, &fs, sizeof(fs)) ? -1 : fs.attrFile;
#else
  USHORT mode;
  return DosQFileMode(name, &mode, 0L) ? -1 : mode;
#endif
}

long GetFileTime(char *name)
{
#ifdef __32BIT__
  FILESTATUS3 fs;
#else
  FILESTATUS fs;
#endif
  USHORT nDate, nTime;

  if ( DosQueryPathInfo(name, 1, (PBYTE) &fs, sizeof(fs)) )
    return -1;

  nDate = * (USHORT *) &fs.fdateLastWrite;
  nTime = * (USHORT *) &fs.ftimeLastWrite;

  return ((ULONG) nDate) << 16 | nTime;
}

void SetFileTime(char *path, long stamp)
{
  FILESTATUS fs;
  USHORT fd, ft;
  USHORT nLength;
  char szName[CCHMAXPATH];

  if ( DosQueryPathInfo(path, FIL_STANDARD, (PBYTE) &fs, sizeof(fs)) )
    return;

  fd = (USHORT) (stamp >> 16);
  ft = (USHORT) stamp;
  fs.fdateLastWrite = fs.fdateCreation = * (FDATE *) &fd;
  fs.ftimeLastWrite = fs.ftimeCreation = * (FTIME *) &ft;

  DosSetPathInfo(path, FIL_STANDARD, (PBYTE) &fs, sizeof(fs), 0);
}


/* FAT / HPFS name conversion stuff */

int IsFileNameValid(char *name)
{
  HFILE hf;
#ifdef __32BIT__
  ULONG uAction;
#else
  USHORT uAction;
#endif

  switch( DosOpen(name, &hf, &uAction, 0, 0, FILE_OPEN,
                  OPEN_ACCESS_READONLY | OPEN_SHARE_DENYNONE, 0) )
  {
  case ERROR_INVALID_NAME:
  case ERROR_FILENAME_EXCED_RANGE:
    return FALSE;
  case NO_ERROR:
    DosClose(hf);
  default:
    return TRUE;
  }
}


void ChangeNameForFAT(char *name)
{
  char *src, *dst, *next, *ptr, *dot, *start;
  static char invalid[] = ":;,=+\"[]<>| \t";

  if ( isalpha(name[0]) && (name[1] == ':') )
    start = name + 2;
  else
    start = name;

  src = dst = start;
  if ( (*src == '/') || (*src == '\\') )
    src++, dst++;

  while ( *src )
  {
    for ( next = src; *next && (*next != '/') && (*next != '\\'); next++ );

    for ( ptr = src, dot = NULL; ptr < next; ptr++ )
      if ( *ptr == '.' )
      {
        dot = ptr; /* remember last dot */
        *ptr = '_';
      }

    if ( dot == NULL )
      for ( ptr = src; ptr < next; ptr++ )
        if ( *ptr == '_' )
          dot = ptr; /* remember last _ as if it were a dot */

    if ( dot && (dot > src) &&
         ((next - dot <= 4) ||
          ((next - src > 8) && (dot - src > 3))) )
    {
      if ( dot )
        *dot = '.';

      for ( ptr = src; (ptr < dot) && ((ptr - src) < 8); ptr++ )
        *dst++ = *ptr;

      for ( ptr = dot; (ptr < next) && ((ptr - dot) < 4); ptr++ )
        *dst++ = *ptr;
    }
    else
    {
      if ( dot && (next - src == 1) )
        *dot = '.';           /* special case: "." as a path component */

      for ( ptr = src; (ptr < next) && ((ptr - src) < 8); ptr++ )
        *dst++ = *ptr;
    }

    *dst++ = *next; /* either '/' or 0 */

    if ( *next )
    {
      src = next + 1;

      if ( *src == 0 ) /* handle trailing '/' on dirs ! */
        *dst = 0;
    }
    else
      break;
  }

  for ( src = start; *src != 0; ++src )
    if ( (strchr(invalid, *src) != NULL) || (*src == ' ') )
      *src = '_';
}


/* .LONGNAME EA code */

typedef struct
{