msdos.c

压缩解压,是unzip540的升级,这个外国网站摘来的源码,是evb编写.

/****************************/

static void maskDOSdevice(__G__ pathcomp, last_dot)
    __GDEF
    char *pathcomp, *last_dot;
{
/*---------------------------------------------------------------------------
    Put an underscore in front of the file name if the file name is a
    DOS/WINDOWS device name like CON.*, AUX.*, PRN.*, etc. Trying to
    extract such a file would fail at best and wedge us at worst.
  ---------------------------------------------------------------------------*/
#if !defined(S_IFCHR) && defined(_S_IFCHR)
#  define S_IFCHR _S_IFCHR
#endif
#if !defined(S_ISCHR)
# if defined(_S_ISCHR)
#  define S_ISCHR(m) _S_ISCHR(m)
# elif defined(S_IFCHR)
#  define S_ISCHR(m) ((m) & S_IFCHR)
# endif
#endif

#ifdef DEBUG
    if (stat(pathcomp, &G.statbuf) == 0) {
        Trace((stderr,
               "maskDOSdevice() stat(\"%s\", buf) st_mode result: %X, %o\n",
               FnFilter1(pathcomp), G.statbuf.st_mode, G.statbuf.st_mode));
    } else {
        Trace((stderr, "maskDOSdevice() stat(\"%s\", buf) failed\n",
               FnFilter1(pathcomp)));
    }
#endif
    if (stat(pathcomp, &G.statbuf) == 0 && S_ISCHR(G.statbuf.st_mode)) {
        extent i;

        /* pathcomp contains a name of a DOS character device (builtin or
         * installed device driver).
         * Prepend a '_' to allow creation of the item in the file system.
         */
        for (i = strlen(pathcomp) + 1; i > 0; --i)
            pathcomp[i] = pathcomp[i - 1];
        pathcomp[0] = '_';
        if (last_dot != (char *)NULL)
            last_dot++;
    }
} /* end function maskDOSdevice() */





#ifdef MAYBE_PLAIN_FAT

/**********************/
/* Function map2fat() */
/**********************/

static void map2fat(pathcomp, last_dot)
    char *pathcomp, *last_dot;
{
    char *pEnd = pathcomp + strlen(pathcomp);

/*---------------------------------------------------------------------------
    Case 1:  filename has no dot, so figure out if we should add one.  Note
    that the algorithm does not try to get too fancy:  if there are no dots
    already, the name either gets truncated at 8 characters or the last un-
    derscore is converted to a dot (only if more characters are saved that
    way).  In no case is a dot inserted between existing characters.

              GRR:  have problem if filename is volume label??

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

    if (last_dot == (char *)NULL) {   /* no dots:  check for underscores... */
        char *plu = strrchr(pathcomp, '_');   /* pointer to last underscore */

        if ((plu != (char *)NULL) &&    /* found underscore: convert to dot? */
            (MIN(plu - pathcomp, 8) + MIN(pEnd - plu - 1, 3) > 8)) {
            last_dot = plu;       /* be lazy:  drop through to next if-block */
        } else if ((pEnd - pathcomp) > 8)
            /* no underscore; or converting underscore to dot would save less
               chars than leaving everything in the basename */
            pathcomp[8] = '\0';     /* truncate at 8 chars */
        /* else whole thing fits into 8 chars or less:  no change */
    }

/*---------------------------------------------------------------------------
    Case 2:  filename has dot in it, so truncate first half at 8 chars (shift
    extension if necessary) and second half at three.
  ---------------------------------------------------------------------------*/

    if (last_dot != (char *)NULL) {     /* one dot is OK: */
        *last_dot = '.';                /* put the last back in */

        if ((last_dot - pathcomp) > 8) {
            char *p, *q;
            int i;

            p = last_dot;
            q = last_dot = pathcomp + 8;
            for (i = 0;  (i < 4) && *p;  ++i) /* too many chars in basename: */
                *q++ = *p++;                  /*  shift extension left and */
            *q = '\0';                        /*  truncate/terminate it */
        } else if ((pEnd - last_dot) > 4)
            last_dot[4] = '\0';               /* too many chars in extension */
        /* else filename is fine as is:  no change */

        if ((last_dot - pathcomp) > 0 && last_dot[-1] == ' ')
            last_dot[-1] = '_';               /* NO blank in front of '.'! */
    }
} /* end function map2fat() */

#endif /* MAYBE_PLAIN_FAT */





/***********************/
/* Function checkdir() */
/***********************/

int checkdir(__G__ pathcomp, flag)
    __GDEF
    char *pathcomp;
    int flag;
/*
 * returns:
 *  MPN_OK          - no problem detected
 *  MPN_INF_TRUNC   - (on APPEND_NAME) truncated filename
 *  MPN_INF_SKIP    - path doesn't exist, not allowed to create
 *  MPN_ERR_SKIP    - path doesn't exist, tried to create and failed; or path
 *                    exists and is not a directory, but is supposed to be
 *  MPN_ERR_TOOLONG - path is too long
 *  MPN_NOMEM       - can't allocate memory for filename buffers
 */
{
    static int rootlen = 0;   /* length of rootpath */
    static char *rootpath;    /* user's "extract-to" directory */
    static char *buildpath;   /* full path (so far) to extracted file */
    static char *end;         /* pointer to end of buildpath ('\0') */
#ifdef MSC
    int attrs;                /* work around MSC stat() bug */
#endif

#   define FN_MASK   7
#   define FUNCTION  (flag & FN_MASK)



/*---------------------------------------------------------------------------
    APPEND_DIR:  append the path component to the path being built and check
    for its existence.  If doesn't exist and we are creating directories, do
    so for this one; else signal success or error as appropriate.
  ---------------------------------------------------------------------------*/

    if (FUNCTION == APPEND_DIR) {
        int too_long = FALSE;

        Trace((stderr, "appending dir segment [%s]\n", FnFilter1(pathcomp)));
        while ((*end = *pathcomp++) != '\0')
            ++end;

        /* GRR:  could do better check, see if overrunning buffer as we go:
         * check end-buildpath after each append, set warning variable if
         * within 20 of FILNAMSIZ; then if var set, do careful check when
         * appending.  Clear variable when begin new path. */

        if ((end-buildpath) > FILNAMSIZ-3)  /* need '/', one-char name, '\0' */
            too_long = TRUE;                /* check if extracting directory? */
#ifdef MSC /* MSC 6.00 bug:  stat(non-existent-dir) == 0 [exists!] */
        if (_dos_getfileattr(buildpath, &attrs) || stat(buildpath, &G.statbuf))
#else
        if (SSTAT(buildpath, &G.statbuf))   /* path doesn't exist */
#endif
        {
            if (!G.create_dirs) { /* told not to create (freshening) */
                free(buildpath);
                /* path doesn't exist:  nothing to do */
                return MPN_INF_SKIP;
            }
            if (too_long) {
                Info(slide, 1, ((char *)slide, LoadFarString(PathTooLong),
                  FnFilter1(buildpath)));
                free(buildpath);
                /* no room for filenames:  fatal */
                return MPN_ERR_TOOLONG;
            }
            if (MKDIR(buildpath, 0777) == -1) {   /* create the directory */
                Info(slide, 1, ((char *)slide, LoadFarString(CantCreateDir),
                  FnFilter2(buildpath), FnFilter1(G.filename)));
                free(buildpath);
                /* path didn't exist, tried to create, failed */
                return MPN_ERR_SKIP;
            }
            created_dir = TRUE;
        } else if (!S_ISDIR(G.statbuf.st_mode)) {
            Info(slide, 1, ((char *)slide, LoadFarString(DirIsntDirectory),
              FnFilter2(buildpath), FnFilter1(G.filename)));
            free(buildpath);
            /* path existed but wasn't dir */
            return MPN_ERR_SKIP;
        }
        if (too_long) {
            Info(slide, 1, ((char *)slide, LoadFarString(PathTooLong),
              FnFilter1(buildpath)));
            free(buildpath);
            /* no room for filenames:  fatal */
            return MPN_ERR_TOOLONG;
        }
        *end++ = '/';
        *end = '\0';
        Trace((stderr, "buildpath now = [%s]\n", FnFilter1(buildpath)));
        return MPN_OK;

    } /* end if (FUNCTION == APPEND_DIR) */

/*---------------------------------------------------------------------------
    GETPATH:  copy full path to the string pointed at by pathcomp, and free
    buildpath.
  ---------------------------------------------------------------------------*/

    if (FUNCTION == GETPATH) {
        strcpy(pathcomp, buildpath);
        Trace((stderr, "getting and freeing path [%s]\n",
          FnFilter1(pathcomp)));
        free(buildpath);
        buildpath = end = (char *)NULL;
        return MPN_OK;
    }

/*---------------------------------------------------------------------------
    APPEND_NAME:  assume the path component is the filename; append it and
    return without checking for existence.
  ---------------------------------------------------------------------------*/

    if (FUNCTION == APPEND_NAME) {
#ifdef NOVELL_BUG_WORKAROUND
        if (end == buildpath && !G.pInfo->vollabel) {
            /* work-around for Novell's "overwriting executables" bug:
               prepend "./" to name when no path component is specified */
            *end++ = '.';
            *end++ = '/';
        }
#endif /* NOVELL_BUG_WORKAROUND */
        Trace((stderr, "appending filename [%s]\n", FnFilter1(pathcomp)));
        while ((*end = *pathcomp++) != '\0') {
            ++end;
            if ((end-buildpath) >= FILNAMSIZ) {
                *--end = '\0';
                Info(slide, 1, ((char *)slide, LoadFarString(PathTooLongTrunc),
                  FnFilter1(G.filename), FnFilter2(buildpath)));
                return MPN_INF_TRUNC;   /* filename truncated */
            }
        }
        Trace((stderr, "buildpath now = [%s]\n", FnFilter1(buildpath)));
        /* could check for existence here, prompt for new name... */
        return MPN_OK;
    }

/*---------------------------------------------------------------------------
    INIT:  allocate and initialize buffer space for the file currently being
    extracted.  If file was renamed with an absolute path, don't prepend the
    extract-to path.
  ---------------------------------------------------------------------------*/

    if (FUNCTION == INIT) {
        Trace((stderr, "initializing buildpath to "));
        /* allocate space for full filename, root path, and maybe "./" */
        if ((buildpath = (char *)malloc(strlen(G.filename)+rootlen+3)) ==
            (char *)NULL)
            return MPN_NOMEM;
        if (G.pInfo->vollabel) {
/* GRR:  for network drives, do strchr() and return IZ_VOL_LABEL if not [1] */
            if (renamed_fullpath && pathcomp[1] == ':')
                *buildpath = (char)ToLower(*pathcomp);
            else if (!renamed_fullpath && rootlen > 1 && rootpath[1] == ':')
                *buildpath = (char)ToLower(*rootpath);
            else {
                GETDRIVE(nLabelDrive);   /* assumed that a == 1, b == 2, etc. */
                *buildpath = (char)(nLabelDrive - 1 + 'a');
            }
            nLabelDrive = *buildpath - 'a' + 1;        /* save for mapname() */
            if (uO.volflag == 0 || *buildpath < 'a' || /* no label/bogus disk */
               (uO.volflag == 1 && !isfloppy(nLabelDrive))) /* -$:  no fixed */
            {
                free(buildpath);
                return MPN_VOL_LABEL;    /* skipping with message */
            }
            *buildpath = '\0';
            end = buildpath;
        } else if (renamed_fullpath) {   /* pathcomp = valid data */
            end = buildpath;
            while ((*end = *pathcomp++) != '\0')
                ++end;
        } else if (rootlen > 0) {
            strcpy(buildpath, rootpath);
            end = buildpath + rootlen;
        } else {
            *buildpath = '\0';
            end = buildpath;
        }
        Trace((stderr, "[%s]\n", FnFilter1(buildpath)));
        return MPN_OK;
    }

/*---------------------------------------------------------------------------
    ROOT:  if appropriate, store the path in rootpath and create it if neces-
    sary; else assume it's a zipfile member and return.  This path segment
    gets used in extracting all members from every zipfile specified on the
    command line.  Note that under OS/2 and MS-DOS, if a candidate extract-to
    directory specification includes a drive letter (leading "x:"), it is
    treated just as if it had a trailing '/'--that is, one directory level
    will be created if the path doesn't exist, unless this is otherwise pro-
    hibited (e.g., freshening).
  ---------------------------------------------------------------------------*/

#if (!defined(SFX) || defined(SFX_EXDIR))
    if (FUNCTION == ROOT) {
        Trace((stderr, "initializing root path to [%s]\n",
          FnFilter1(pathcomp)));
        if (pathcomp == (char *)NULL) {
            rootlen = 0;
            return MPN_OK;
        }
        if (rootlen > 0)        /* rootpath was already set, nothing to do */
            return MPN_OK;
        if ((rootlen = strlen(pathcomp)) > 0) {
            int had_trailing_pathsep=FALSE, has_drive=FALSE, add_dot=FALSE;
            char *tmproot;

            if ((tmproot = (char *)malloc(rootlen+3)) == (char *)NULL) {
                rootlen = 0;
                return MPN_NOMEM;
            }
            strcpy(tmproot, pathcomp);
            if (isalpha((uch)tmproot[0]) && tmproot[1] == ':')
                has_drive = TRUE;   /* drive designator */
            if (tmproot[rootlen-1] == '/' || tmproot[rootlen-1] == '\\') {
                tmproot[--rootlen] = '\0';
                had_trailing_pathsep = TRUE;
            }
            if (has_drive && (rootlen == 2)) {
                if (!had_trailing_pathsep)   /* i.e., original wasn't "x:/" */
                    add_dot = TRUE;    /* relative path: add '.' before '/' */
            } else if (rootlen > 0) {     /* need not check "x:." and "x:/" */
#ifdef MSC
                /* MSC 6.00 bug:  stat(non-existent-dir) == 0 [exists!] */
                if (_dos_getfileattr(tmproot, &attrs) ||
                    SSTAT(tmproot, &G.statbuf) || !S_ISDIR(G.statbuf.st_mode))
#else
                if (SSTAT(tmproot, &G.statbuf) || !S_ISDIR(G.statbuf.st_mode))
#endif
                {
                    /* path does not exist */
                    if (!G.create_dirs /* || iswild(tmproot) */ ) {
                        free(tmproot);
                        rootlen = 0;
                        /* treat as stored file */
                        return MPN_INF_SKIP;
                    }
/* GRR:  scan for wildcard characters?  OS-dependent...  if find any, return 2:
 * treat as stored file(s) */
                    /* create directory (could add loop here scanning tmproot
                     * to create more than one level, but really necessary?) */