vmszip.c

给出了 zip 压缩算法的完整实现过程。

               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 */
  if ((s.st_mode & S_IFDIR) == 0)
  {
    /* add or remove name of file */
    if ((m = newname(n, 0, caseflag)) != ZE_OK)
      return m;
  } else {
    if (dirnames && (m = newname(n, 1, caseflag)) != ZE_OK) {
      return m;
    }
    /* recurse into directory */
    if (recurse && (d = zopendir(n)) != NULL)
    {
      while ((e = readd(d)) != NULL) {
        if ((m = procname(e, caseflag)) != ZE_OK)     /* recurse on name */
        {
          free(d);
          return m;
        }
      }
      free(d);
    }
  } /* (s.st_mode & S_IFDIR) == 0) */
  return ZE_OK;
}

/* 2004-09-24 SMS.
   Cuter strlower() and strupper() functions.
*/

local char *strlower( s)
char *s;
/* Convert all uppercase letters to lowercase in string s */
{
  for ( ; *s != '\0'; s++)
    if (isupper( *s))
      *s = tolower( *s);

  return s;
}

local char *strupper( s)
char *s;
/* Convert all lowercase letters to uppercase in string s */
{
  for ( ; *s != '\0'; s++)
    if (islower( *s))
      *s = toupper( *s);

  return s;
}

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 = dosify; /* default for non-DOS and non-OS/2 */

  /* Find starting point in name before doing malloc */
  t = x;
  if ((n = strrchr(t, ':')) != NULL)
    t = n + 1;
  if ( (*t == PATH_START && (n = strrchr(t, PATH_END)) != NULL)
      || (*t == PATH_START2 && (n = strrchr(t, PATH_END2)) != NULL) )
    /* external name contains valid VMS path specification */
    if (*(++t) == '.')
      /* path is relative to current directory, skip leading '.' */
      t++;

  if (!pathput)
    t = last(last(t, PATH_END), PATH_END2);

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

  if (((t = strrchr(n, PATH_END)) != NULL) ||
       (t = strrchr(n, PATH_END2)) != NULL)
  {
    *t = '/';
    while (--t > n)
      if (*t == '.')
        *t = '/';
  }

  /* Fix from Greg Roelofs: */
  /* Get current working directory and strip from n (t now = n) */
  {
    char cwd[256], *p, *q;
    int c;

    q = getcwd( cwd, 256);

    /* 2004-09-24 SMS.
       With SET PROCESSS /PARSE = EXTENDED, getcwd() can return a
       mixed-case result, confounding the comparisons below with an
       all-uppercase name in "n".  Always use a case-insensitive
       comparison around here.
    */

#if 0 /* fix by Igor */
    if ((q != NULL) && ((p = strchr(cwd, '.')) != NULL))
#else
    if ((q != NULL) && ((p = strchr(cwd, PATH_START)) != NULL ||
                        (p = strchr(cwd, PATH_START2)) != NULL))
#endif
    {
      if (*(++p) == '.')
        p++;
      if ((q = strrchr(p, PATH_END)) != NULL ||
          (q = strrchr(p, PATH_END2)) != NULL)
      {
        *q = '/';
        while (--q > p)
          if (*q == '.')
            *q = '/';

        /* strip bogus path parts from n */
        if (strncasecmp( n, p, (c = strlen( p))) == 0)
        {
          q = n + c;
          while (*t++ = *q++)
            ;
        }
      }
    }
  }

#ifndef VMS_PRESERVE_CASE
  strlower( n);
#endif /* ndef VMS_PRESERVE_CASE */

  /* Remove simple ODS5 extended file name escape characters. */
  eat_carets( n);

  if (isdir)
  {
    if (strcasecmp( (t = n + strlen( n) - 6), ".DIR;1"))
      error("directory not version 1");
    else
      if (pathput)
        strcpy(t, "/");
      else
        *n = '\0';              /* directories are discarded with zip -rj */
  }
  else if (!vmsver)
    if ((t = strrchr(n, ';')) != NULL)
      *t = '\0';

  if ((t = strrchr(n, '.')) != NULL)
  {
    if ( t[1] == '\0')          /* "filename." -> "filename" */
      *t = '\0';
    else if (t[1] == ';')       /* "filename.;vvv" -> "filename;vvv" */
    {
      char *f = t+1;
      while (*t++ = *f++) ;
    }
  }

  if (dosify)
    msname(n);

  /* Returned malloc'ed name */
  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 */
  char *t;              /* scans name */

  if ((t = strrchr(n, '/')) == NULL)
  {
    if ((x = malloc(strlen(n) + 1 + PAD)) == NULL)
      return NULL;
    strcpy(x, n);
  }
  else
  {
    if ((x = malloc(strlen(n) + 3 + PAD)) == NULL)
      return NULL;
    x[0] = PATH_START;
    x[1] = '.';
    strcpy(x + 2, n);
    *(t = x + 2 + (t - n)) = PATH_END;
    while (--t > x)
      if (*t == '/')
        *t = '.';
  }

#ifndef VMS_PRESERVE_CASE
  strupper( x);
#endif /* ndef VMS_PRESERVE_CASE */

  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. */
{
  int tm_sec, tm_min, tm_hour, tm_mday, tm_mon, tm_year;
  char timbuf[24];
  static ZCONST char *month[] = {"JAN", "FEB", "MAR", "APR", "MAY", "JUN",
                                 "JUL", "AUG", "SEP", "OCT", "NOV", "DEC"};
  struct VMStimbuf {
      char *actime;           /* VMS revision date, ASCII format */
      char *modtime;          /* VMS creation date, ASCII format */
  } ascii_times;

  ascii_times.actime = ascii_times.modtime = timbuf;

  /* Convert DOS time to ASCII format for VMSmunch */
  tm_sec = (int)(d << 1) & 0x3e;
  tm_min = (int)(d >> 5) & 0x3f;
  tm_hour = (int)(d >> 11) & 0x1f;
  tm_mday = (int)(d >> 16) & 0x1f;
  tm_mon = ((int)(d >> 21) & 0xf) - 1;
  tm_year = ((int)(d >> 25) & 0x7f) + 1980;
  sprintf(timbuf, "%02d-%3s-%04d %02d:%02d:%02d.00", tm_mday, month[tm_mon],
    tm_year, tm_hour, tm_min, tm_sec);

  /* Set updated and accessed times of f */
  if (VMSmunch(f, SET_TIMES, (char *)&ascii_times) != RMS$_NMF)
    zipwarn("can't set zipfile time: ", f);
}

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() */
  /* malloc name so not dependent on FNMAX - 11/8/04 EG */
  char *name;
  int len = strlen(f);

  if (f == label) {
    if (a != NULL)
      *a = label_mode;
    if (n != NULL)
      *n = -2; /* 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 (strcmp(f, "-") == 0) {
    if (fstat(fileno(stdin), &s) != 0) {
      free(name);
      error("fstat(stdin)");
    }
  } else if (LSSTAT(name, &s) != 0) {
             /* Accept about any file kind including directories
              * (stored with trailing / with -r option)
              */
    free(name);
    return 0;
  }
  free(name);

  if (a != NULL) {
    *a = ((ulg)s.st_mode << 16) | !(s.st_mode & S_IWRITE);
    if ((s.st_mode & S_IFDIR) != 0) {
      *a |= MSDOS_DIR_ATTR;
    }
  }
  if (n != NULL)
    *n = (s.st_mode & S_IFMT) == S_IFREG ? s.st_size : -1;
  if (t != NULL) {
    t->atime = s.st_mtime;
#ifdef USE_MTIME
    t->mtime = s.st_mtime;            /* Use modification time in VMS */
#else
    t->mtime = s.st_ctime;            /* Use creation time in VMS */
#endif
    t->ctime = s.st_ctime;
  }

#ifdef USE_MTIME
  return unix2dostime((time_t *)&s.st_mtime); /* Use modification time in VMS */
#else
  return unix2dostime((time_t *)&s.st_ctime); /* Use creation time in VMS */
#endif
}

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().
   For VMS, d must be in format [x.y]z.dir;1  (not [x.y.z]).
 */
{
    /* code from Greg Roelofs, who horked it from Mark Edwards (unzip) */
    int r, len;
    char *s;              /* malloc'd string for system command */

    len = strlen(d);
    if ((s = malloc(len + 34)) == NULL)
      return 127;

    system(strcat(strcpy(s, "set prot=(o:rwed) "), d));
    r = delete(d);
    free(s);
    return r;
}

#endif /* !UTIL */