msdos.c

完整的解压zip文件的源码。包含密码功能

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

int checkdir(__G__ pathcomp, flag)
    __GDEF
    char *pathcomp;
    int flag;
/*
 * returns:  1 - (on APPEND_NAME) truncated filename
 *           2 - path doesn't exist, not allowed to create
 *           3 - path doesn't exist, tried to create and failed; or
 *               path exists and is not a directory, but is supposed to be
 *           4 - path is too long
 *          10 - 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", 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);
                return 2;         /* path doesn't exist:  nothing to do */
            }
            if (too_long) {
                Info(slide, 1, ((char *)slide, LoadFarString(PathTooLong),
                  FnFilter1(buildpath)));
                free(buildpath);
                return 4;         /* no room for filenames:  fatal */
            }
            if (MKDIR(buildpath, 0777) == -1) {   /* create the directory */
                Info(slide, 1, ((char *)slide, LoadFarString(CantCreateDir),
                  FnFilter2(buildpath), FnFilter1(G.filename)));
                free(buildpath);
                return 3;      /* path didn't exist, tried to create, failed */
            }
            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);
            return 3;          /* path existed but wasn't dir */
        }
        if (too_long) {
            Info(slide, 1, ((char *)slide, LoadFarString(PathTooLong),
              FnFilter1(buildpath)));
            free(buildpath);
            return 4;         /* no room for filenames:  fatal */
        }
        *end++ = '/';
        *end = '\0';
        Trace((stderr, "buildpath now = [%s]\n", FnFilter1(buildpath)));
        return 0;

    } /* 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 0;
    }

/*---------------------------------------------------------------------------
    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 1;   /* filename truncated */
            }
        }
        Trace((stderr, "buildpath now = [%s]\n", FnFilter1(buildpath)));
        return 0;  /* could check for existence here, prompt for new name... */
    }

/*---------------------------------------------------------------------------
    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 10;
        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 IZ_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 0;
    }

/*---------------------------------------------------------------------------
    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 0;
        }
        if ((rootlen = strlen(pathcomp)) > 0) {
            int had_trailing_pathsep=FALSE, has_drive=FALSE, xtra=2;

            if (isalpha(pathcomp[0]) && pathcomp[1] == ':')
                has_drive = TRUE;   /* drive designator */
            if (pathcomp[rootlen-1] == '/' || pathcomp[rootlen-1] == '\\') {
                pathcomp[--rootlen] = '\0';
                had_trailing_pathsep = TRUE;
            }
            if (has_drive && (rootlen == 2)) {
                if (!had_trailing_pathsep)   /* i.e., original wasn't "x:/" */
                    xtra = 3;      /* room for '.' + '/' + 0 at end of "x:" */
            } 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(pathcomp, &attrs) ||
                    SSTAT(pathcomp,&G.statbuf) || !S_ISDIR(G.statbuf.st_mode))
#else
                if (SSTAT(pathcomp,&G.statbuf) || !S_ISDIR(G.statbuf.st_mode))
#endif
                {
                    /* path does not exist */
                    if (!G.create_dirs /* || iswild(pathcomp) */ ) {
                        rootlen = 0;
                        return 2;   /* treat as stored file */
                    }
/* GRR:  scan for wildcard characters?  OS-dependent...  if find any, return 2:
 * treat as stored file(s) */
                    /* create directory (could add loop here to scan pathcomp
                     * and create more than one level, but really necessary?) */
                    if (MKDIR(pathcomp, 0777) == -1) {
                        Info(slide, 1, ((char *)slide,
                          LoadFarString(CantCreateExtractDir),
                          FnFilter1(pathcomp)));
                        rootlen = 0;   /* path didn't exist, tried to create, */
                        return 3;  /* failed:  file exists, or need 2+ levels */
                    }
                }
            }
            if ((rootpath = (char *)malloc(rootlen+xtra)) == (char *)NULL) {
                rootlen = 0;
                return 10;
            }
            strcpy(rootpath, pathcomp);
            if (xtra == 3)                  /* had just "x:", make "x:." */
                rootpath[rootlen++] = '.';
            rootpath[rootlen++] = '/';
            rootpath[rootlen] = '\0';
            Trace((stderr, "rootpath now = [%s]\n", FnFilter1(rootpath)));
        }
        return 0;
    }
#endif /* !SFX || SFX_EXDIR */

/*---------------------------------------------------------------------------
    END:  free rootpath, immediately prior to program exit.
  ---------------------------------------------------------------------------*/

    if (FUNCTION == END) {
        Trace((stderr, "freeing rootpath\n"));
        if (rootlen > 0) {
            free(rootpath);
            rootlen = 0;
        }
        return 0;
    }

    return 99;  /* should never reach */

} /* end function checkdir() */






/***********************/
/* Function isfloppy() */
/***********************/

static int isfloppy(nDrive)  /* more precisely, is it removable? */
    int nDrive;
{
    union REGS regs;

    regs.h.ah = 0x44;
    regs.h.al = 0x08;
    regs.h.bl = (uch)nDrive;
#ifdef __EMX__
    _int86(0x21, &regs, &regs);
    if (WREGS(regs,flags) & 1)
#else
    intdos(&regs, &regs);
    if (WREGS(regs,cflag))        /* error:  do default a/b check instead */
#endif
    {
        Trace((stderr,
          "error in DOS function 0x44 (AX = 0x%04x):  guessing instead...\n",
          WREGS(regs,ax)));
        return (nDrive == 1 || nDrive == 2)? TRUE : FALSE;
    } else
        return WREGS(regs,ax)? FALSE : TRUE;
}




/**************************/
/* Function z_dos_chmod() */
/**************************/

static int z_dos_chmod(__G__ fname, attributes)
    __GDEF
    ZCONST char *fname;
    int attributes;
{
    char *name;
    unsigned fnamelength;
    int errv;

    /* set file attributes:
       The DOS `chmod' system call requires to mask out the
       directory and volume_label attribute bits.
       And, a trailing '/' has to be removed from the directory name,
       the DOS `chmod' system call does not accept it. */
    fnamelength = strlen(fname);
    if (fnamelength > 1 && fname[fnamelength-1] == '/' &&
        fname[fnamelength-2] != ':' &&
        (name = (char *)malloc(fnamelength)) != (char *)NULL) {
        strncpy(name, fname, fnamelength-1);
        name[fnamelength-1] = '\0';
    } else {
        name = (char *)fname;
        fnamelength = 0;
    }

#if defined(__TURBOC__) || (defined(__DJGPP__) && (__DJGPP__ >= 2))
#   if (defined(__BORLANDC__) && (__BORLANDC__ >= 0x0452))
#     define Chmod  _rtl_chmod
#   else
#     define Chmod  _chmod
#   endif
    errv = (Chmod(name, 1, attributes & (~FSUBDIR & ~FVOLID)) !=
            (attributes & (~FSUBDIR & ~FVOLID)));
#   undef Chmod
#else /* !(__TURBOC__ || (__DJGPP__ && __DJGPP__ >= 2)) */
    errv = (_dos_setfileattr(name, attributes & (~FSUBDIR & ~FVOLID)) != 0);
#endif /* ?(__TURBOC__ || (__DJGPP__ && __DJGPP__ >= 2)) */
    if (errv)
        Info(slide, 1, ((char *)slide, LoadFarString(AttribsMayBeWrong)));

    if (fnamelength > 0)
        free(name);
    return errv;
} /* end function z_dos_chmod() */




#if (!defined(__GO32__) && !defined(__EMX__))

typedef struct dosfcb {
    uch  flag;        /* ff to indicate extended FCB */
    char res[5];      /* reserved */
    uch  vattr;       /* attribute */
    uch  drive;       /* drive (1=A, 2=B, ...) */
    uch  vn[11];      /* file or volume name */
    char dmmy[5];
    uch  nn[11];      /* holds new name if renaming (else reserved) */
    char dmmy2[9];