msdos.c

给出了 zip 压缩算法的完整实现过程。

      {
        z->mark = pcount ? filter(z->zname, caseflag) : 1;
        if (z->mark) z->dosflag = 1;    /* force DOS attribs for incl. names */
        if (verbose)
            fprintf(mesg, "zip diagnostic: %scluding %s\n",
               z->mark ? "in" : "ex", z->name);
        m = 0;
      }
    }
    free((zvoid *)p);
    return m ? ZE_MISS : ZE_OK;
  }

  /* Live name--use if file, recurse if directory */
  for (p = n; *p; p++)          /* use / consistently */
    if (*p == '\\')
      *p = '/';
  if ((s.st_mode & S_IFDIR) == 0)
  {
    /* add or remove name of file */
    if ((m = newname(n, 0, caseflag)) != ZE_OK)
      return m;
  } else {
    /* Add trailing / to the directory name */
    if ((p = malloc(strlen(n)+2)) == NULL)
      return ZE_MEM;
    if (strcmp(n, ".") == 0 || strcmp(n, "/.") == 0) {
      *p = '\0';  /* avoid "./" prefix and do not create zip entry */
    } else {
      strcpy(p, n);
      a = p + strlen(p);
      if (a[-1] != '/')
        strcpy(a, "/");
      if (dirnames && (m = newname(p, 1, caseflag)) != ZE_OK) {
        free((zvoid *)p);
        return m;
      }
    }
    /* recurse into directory */
    if (recurse)
    {
      if ((d = malloc(sizeof(ff_dir))) == NULL ||
          (m = initDirSearch(n, d)) == ZE_MEM)
      {
        if (d != NULL)
          free((zvoid *)d);
        free((zvoid *)p);
        return ZE_MEM;
      }
      for (e = d->ff_name, ff_status = m;
           ff_status == 0;
           ff_status = FNEXT(d))
      {
        if (strcmp(e, ".") && strcmp(e, ".."))
        {
          if ((a = malloc(strlen(p) + strlen(e) + 1)) == NULL)
          {
            free((zvoid *)d);
            free((zvoid *)p);
            return ZE_MEM;
          }
          strcat(strcpy(a, p), e);
          if ((m = procname_dos(a, caseflag, getDirEntryAttr(d)))
              != ZE_OK)         /* recurse on name */
          {
            if (m == ZE_MISS)
              zipwarn("name not matched: ", a);
            else
              ziperr(m, a);
          }
          free((zvoid *)a);
        }
      }
      free((zvoid *)d);
    }
    free((zvoid *)p);
  } /* (s.st_mode & S_IFDIR) == 0) */
  return ZE_OK;
}

int procname(n, caseflag)
char *n;                /* name to process */
int caseflag;           /* true to force case-sensitive match */
{
  return procname_dos(n, caseflag, MSDOS_INVALID_ATTR);
}

char *ex2in(x, isdir, pdosflag)
char *x;                /* external file name */
int isdir;              /* input: x is a directory */
int *pdosflag;          /* output: force MSDOS file attributes? */
/* Convert the external file name to a zip file name, returning the malloc'ed
   string or NULL if not enough memory. */
{
  char *n;              /* internal file name (malloc'ed) */
  char *t;              /* shortened name */
  int dosflag;

  dosflag = 1;

  /* Find starting point in name before doing malloc */
  /* Strip drive specification */
  t = *x && *(x + 1) == ':' ? x + 2 : x;
  /* Strip "//host/share/" part of a UNC name */
  if ((!strncmp(x,"//",2) || !strncmp(x,"\\\\",2)) &&
      (x[2] != '\0' && x[2] != '/' && x[2] != '\\')) {
    n = x + 2;
    while (*n != '\0' && *n != '/' && *n != '\\')
      n++;              /* strip host name */
    if (*n != '\0') {
      n++;
      while (*n != '\0' && *n != '/' && *n != '\\')
        n++;            /* strip `share' name */
    }
    if (*n != '\0')
      t = n + 1;
  }
  /* Strip leading "/" to convert an absolute path into a relative path */
  while (*t == '/' || *t == '\\')
    t++;
  /* Skip leading "./" as well */
  while (*t == '.' && (t[1] == '/' || t[1] == '\\'))
    t += 2;

  /* Make changes, if any, to the copied name (leave original intact) */
  for (n = t; *n; n++)
    if (*n == '\\')
      *n = '/';

  if (!pathput)
    t = last(t, PATH_END);

  /* Malloc space for internal name and copy it */
  if ((n = malloc(strlen(t) + 1)) == NULL)
    return NULL;
  strcpy(n, t);

  if (isdir == 42) return n;      /* avoid warning on unused variable */

  if (dosify)
    msname(n);
  else
#if defined(__DJGPP__) && __DJGPP__ >= 2
    if (_USE_LFN == 0)
#endif
      strlwr(n);
  if (pdosflag)
    *pdosflag = dosflag;
  return n;
}

char *in2ex(n)
char *n;                /* internal file name */
/* Convert the zip file name to an external file name, returning the malloc'ed
   string or NULL if not enough memory. */
{
  char *x;              /* external file name */

  if ((x = malloc(strlen(n) + 1 + PAD)) == NULL)
      return NULL;
  strcpy(x, n);

  return x;
}

void stamp(f, d)
char *f;                /* name of file to change */
ulg d;                  /* dos-style time to change it to */
/* Set last updated and accessed time of file f to the DOS time d. */
{
#if defined(__TURBOC__) || defined(__GO32__)
  int h;                /* file handle */

  if ((h = open(f, 0)) != -1)
  {
    setftime(h, (struct ftime *)(void *)&d);
    close(h);
  }
#else /* !__TURBOC__ && !__GO32__ */
  ztimbuf u;            /* argument for utime() */

  /* Convert DOS time to time_t format in u.actime and u.modtime */
  u.actime = u.modtime = dos2unixtime(d);

  /* Set updated and accessed times of f */
  utime(f, &u);
#endif /* ?(__TURBOC__ || __GO32__) */
}

ulg filetime(f, a, n, t)
char *f;                /* name of file to get info on */
ulg *a;                 /* return value: file attributes */
long *n;                /* return value: file size */
iztimes *t;             /* return value: access, modific. and creation times */
/* If file *f does not exist, return 0.  Else, return the file's last
   modified date and time as an MSDOS date and time.  The date and
   time is returned in a long with the date most significant to allow
   unsigned integer comparison of absolute times.  Also, if a is not
   a NULL pointer, store the file attributes there, with the high two
   bytes being the Unix attributes, and the low byte being a mapping
   of that to DOS attributes.  If n is not NULL, store the file size
   there.  If t is not NULL, the file's access, modification and creation
   times are stored there as UNIX time_t values.
   If f is "-", use standard input as the file. If f is a device, return
   a file size of -1 */
{
  struct stat s;        /* results of stat() */
  char *name;
  unsigned int len = strlen(f);
  int isstdin = !strcmp(f, "-");

  if (f == label) {
    if (a != NULL)
      *a = label_mode;
    if (n != NULL)
      *n = -2L; /* convention for a label name */
    if (t != NULL)
      t->atime = t->mtime = t->ctime = label_utim;
    return label_time;
  }

  if ((name = malloc(len + 1)) == NULL) {
    ZIPERR(ZE_MEM, "filetime");
  }
  strcpy(name, f);
  if (name[len - 1] == '/')
    name[len - 1] = '\0';
  /* not all systems allow stat'ing a file with / appended */

  if (isstdin) {
    if (fstat(fileno(stdin), &s) != 0) {
      free(name);
      error("fstat(stdin)");
    }
    time((time_t *)&s.st_mtime);       /* some fstat()s return time zero */
  } else if (LSSTAT(name, &s) != 0) {
             /* Accept about any file kind including directories
              * (stored with trailing / with -r option)
              */
    free(name);
    return 0;
  }

  if (a != NULL) {
    *a = ((ulg)s.st_mode << 16) | (isstdin ? 0L : (ulg)GetFileMode(name));
#if (S_IFREG != 0x8000)
    /* kludge to work around non-standard S_IFREG flag used in DJGPP V2.x */
    if ((s.st_mode & S_IFMT) == S_IFREG) *a |= 0x80000000L;
#endif
  }
  if (n != NULL)
    *n = (s.st_mode & S_IFREG) != 0 ? s.st_size : -1L;
  if (t != NULL) {
    t->atime = s.st_atime;
    t->mtime = s.st_mtime;
    t->ctime = s.st_ctime;
  }

  free(name);

  return unix2dostime((time_t *)&s.st_mtime);
}

int deletedir(d)
char *d;                /* directory to delete */
/* Delete the directory *d if it is empty, do nothing otherwise.
   Return the result of rmdir(), delete(), or system().
 */
{
    return rmdir(d);
}

int set_extra_field(z, z_utim)
  struct zlist far *z;
  iztimes *z_utim;
  /* create extra field and change z->att if desired */
{
#ifdef USE_EF_UT_TIME
#ifdef IZ_CHECK_TZ
  if (!zp_tz_is_valid) return ZE_OK;    /* skip silently if no valid TZ info */
#endif

  if ((z->extra = (char *)malloc(EB_HEADSIZE+EB_UT_LEN(1))) == NULL)
    return ZE_MEM;

  z->extra[0]  = 'U';
  z->extra[1]  = 'T';
  z->extra[2]  = EB_UT_LEN(1);          /* length of data part of e.f. */
  z->extra[3]  = 0;
  z->extra[4]  = EB_UT_FL_MTIME;
  z->extra[5]  = (char)(z_utim->mtime);
  z->extra[6]  = (char)(z_utim->mtime >> 8);
  z->extra[7]  = (char)(z_utim->mtime >> 16);
  z->extra[8]  = (char)(z_utim->mtime >> 24);

  z->cext = z->ext = (EB_HEADSIZE+EB_UT_LEN(1));
  z->cextra = z->extra;

  return ZE_OK;
#else /* !USE_EF_UT_TIME */
  return (int)(z-z);
#endif /* ?USE_EF_UT_TIME */
}


#ifdef MY_ZCALLOC       /* Special zcalloc function for MEMORY16 (MSDOS/OS2) */

#if defined(__TURBOC__) && !defined(OS2)
/* Small and medium model are for now limited to near allocation with
 * reduced MAX_WBITS and MAX_MEM_LEVEL
 */

/* Turbo C malloc() does not allow dynamic allocation of 64K bytes
 * and farmalloc(64K) returns a pointer with an offset of 8, so we
 * must fix the pointer. Warning: the pointer must be put back to its
 * original form in order to free it, use zcfree().
 */

#define MAX_PTR 10
/* 10*64K = 640K */

local int next_ptr = 0;

typedef struct ptr_table_s {
    zvoid far *org_ptr;
    zvoid far *new_ptr;
} ptr_table;

local ptr_table table[MAX_PTR];
/* This table is used to remember the original form of pointers
 * to large buffers (64K). Such pointers are normalized with a zero offset.
 * Since MSDOS is not a preemptive multitasking OS, this table is not
 * protected from concurrent access. This hack doesn't work anyway on
 * a protected system like OS/2. Use Microsoft C instead.
 */

zvoid far *zcalloc (unsigned items, unsigned size)
{
    zvoid far *buf;
    ulg bsize = (ulg)items*size;

    if (bsize < (65536L-16L)) {
        buf = farmalloc(bsize);
        if (*(ush*)&buf != 0) return buf;
    } else {
        buf = farmalloc(bsize + 16L);
    }
    if (buf == NULL || next_ptr >= MAX_PTR) return NULL;
    table[next_ptr].org_ptr = buf;

    /* Normalize the pointer to seg:0 */
    *((ush*)&buf+1) += ((ush)((uch*)buf-NULL) + 15) >> 4;
    *(ush*)&buf = 0;
    table[next_ptr++].new_ptr = buf;
    return buf;
}

zvoid zcfree (zvoid far *ptr)
{
    int n;
    if (*(ush*)&ptr != 0) { /* object < 64K */
        farfree(ptr);
        return;
    }
    /* Find the original pointer */
    for (n = next_ptr - 1; n >= 0; n--) {
        if (ptr != table[n].new_ptr) continue;

        farfree(table[n].org_ptr);
        while (++n < next_ptr) {
            table[n-1] = table[n];
        }
        next_ptr--;
        return;