vms.c

给出了 zip 压缩算法的完整实现过程。

/*
  Copyright (c) 1990-2005 Info-ZIP.  All rights reserved.

  See the accompanying file LICENSE, version 2005-Feb-10 or later
  (the contents of which are also included in zip.h) for terms of use.
  If, for some reason, all these files are missing, the Info-ZIP license
  also may be found at:  ftp://ftp.info-zip.org/pub/infozip/license.html
*/
/*
 *  vms.c (zip) by Igor Mandrichenko    Version 2.2-2
 *
 *  Revision history:
 *  ...
 *  2.2-2       18-jan-1993     I.Mandrichenko
 *      vms_stat() added - version of stat() that handles special
 *      case when end-of-file-block == 0
 *
 *  2.3.1       11-oct-2004     SMS
 *      It would be nice to know why vms_stat() is needed.  If EOF can't
 *      be trusted for a zero-length file, why trust it for any file?
 *      Anyway, I removed the (int) cast on ->st_size, which may now be
 *      bigger than an int, just in case this code ever does get used.
 *      (A true zero-length file should still report zero length, even
 *      after the long fight with RMS.)
 *      Moved the VMS_PK_EXTRA test(s) into VMS_IM.C and VMS_PK.C to
 *      allow more general automatic dependency generation.
 *
 *  2.3.2       02-aug-2005     SMS
 *      General update for commonality with Zip 3.
 *
 */

#ifdef VMS                      /* For VMS only ! */

#define NO_ZIPUP_H              /* prevent inclusion of vms/zipup.h */

#include "zip.h"

#include <stdio.h>
#include <string.h>

#include <jpidef.h>
#include <fab.h>                /* Needed only in old environments. */
#include <nam.h>                /* Needed only in old environments. */
#include <starlet.h>
#include <stsdef.h>

/* On VAX, define Goofy VAX Type-Cast to obviate /standard = vaxc.
   Otherwise, lame system headers on VAX cause compiler warnings.
   (GNU C may define vax but not __VAX.)
*/
#ifdef vax
# define __VAX 1
#endif /* def vax */

#ifdef __VAX
# define GVTC (unsigned int)
#else /* def __VAX */
# define GVTC
#endif /* def __VAX */


#ifdef UTIL

/* For utilities, include only vms.h, as either of the vms_XX.c files
 * would do.
 */

# include "vms.h"

#else /* def UTIL */

/* Include the `VMS attributes' preserving file-io code. We distinguish
   between two incompatible flavours of storing VMS attributes in the
   Zip archive:
   a) The "PKware" style follows the extra field specification for
      PKware's VMS Zip.
   b) The "IM (Info-ZIP)" flavour was defined from scratch by
      Igor Mandrichenko. This version has be used in official Info-ZIP
      releases for several years and is known to work well.
 */

/* Note that only one of these #include directives will include any
 * active code, depending on VMS_PK_EXTRA.  Both are included here (and
 * tested there) to allow more general automatic dependency generation.
 */

#include "vms_pk.c"
#include "vms_im.c"

#endif /* def UTIL */

#ifndef ERR
#define ERR(x) (((x)&1)==0)
#endif

#ifndef NULL
#define NULL (void*)(0L)
#endif

int vms_stat( char *file, stat_t *s)
{
    int status;
    int staterr;
    struct FAB fab;
    struct NAM_STRUCT nam;
    struct XABFHC fhc;

    /*
     *  In simplest case when stat() returns "ok" and file size is
     *  nonzero or this is directory, finish with this
     */

    if( (staterr=stat(file,s)) == 0
        && ( s->st_size >= 0                      /* Size - ok */
             || (s->st_mode & S_IFREG) == 0       /* Not a plain file */
           )
    ) return staterr;

    /*
     *  Get here to handle the special case when stat() returns
     *  invalid file size. Use RMS to compute the size.
     *  When EOF block is zero, set file size to its physical size.
     *  One more case to get here is when this is remote file accessed
     *  via DECnet.
     */

    fab = cc$rms_fab;
    nam = CC_RMS_NAM;
    fhc = cc$rms_xabfhc;
    fab.FAB_NAM = &nam;
    fab.fab$l_xab = (char*)(&fhc);

#ifdef NAML$C_MAXRSS

    fab.fab$l_dna = (char *) -1;    /* Using NAML for default name. */
    fab.fab$l_fna = (char *) -1;    /* Using NAML for file name. */

#endif /* def NAML$C_MAXRSS */

    FAB_OR_NAM( fab, nam).FAB_OR_NAM_FNA = file;
    FAB_OR_NAM( fab, nam).FAB_OR_NAM_FNS = strlen( file);

    fab.fab$b_fac = FAB$M_GET;

    status = sys$open(&fab);
    fab.fab$l_xab = (char*)0L;
    sys$close(&fab);

    if( !ERR(status) )
    {
        if( fhc.xab$l_ebk > 0 )
            s->st_size = ( fhc.xab$l_ebk-1 ) * 512 + fhc.xab$w_ffb;
        else if( fab.fab$b_org == FAB$C_IDX
                 || fab.fab$b_org == FAB$C_REL
                 || fab.fab$b_org == FAB$C_HSH )
                /* Special case, when ebk=0: save entire allocated space */
                    s->st_size = fhc.xab$l_hbk * 512;
        else
            s->st_size = fhc.xab$w_ffb;
        return 0; /* stat() success code */
    }
    else
        return status;
}

void vms_exit(e)
   int e;
{
/*---------------------------------------------------------------------------
    Return an intelligent status/severity level if RETURN_SEVERITY defined:

    $STATUS          $SEVERITY = $STATUS & 7
    31 .. 16 15 .. 3   2 1 0
                       -----
    VMS                0 0 0  0    Warning
    FACILITY           0 0 1  1    Success
    Number             0 1 0  2    Error
             MESSAGE   0 1 1  3    Information
             Number    1 0 0  4    Severe (fatal) error

    0x7FFF0000 was chosen (by experimentation) to be outside the range of
    VMS FACILITYs that have dedicated message numbers.  Hopefully this will
    always result in silent exits--it does on VMS 5.4.  Note that the C li-
    brary translates exit arguments of zero to a $STATUS value of 1 (i.e.,
    exit is both silent and has a $SEVERITY of "success").
  ---------------------------------------------------------------------------*/
  {
    int severity;

    switch (e) {                        /* $SEVERITY: */
      case ZE_NONE:
          severity = 0; break;          /*   warning  */
      case ZE_FORM:
      case ZE_BIG:
      case ZE_NOTE:
      case ZE_ABORT:
      case ZE_NAME:
      case ZE_PARMS:
      case ZE_OPEN:
          severity = 2; break;          /*   error    */
      default:
          severity = 4; break;          /*   fatal    */
    }

    exit(                                       /* $SEVERITY:              */
         (e == ZE_OK) ? 1 :                     /*   success               */
         (0x7FFF0000 | (e << 4) | severity)     /*   warning, error, fatal */
        );
   }
}


/******************************/
/*  Function version_local()  */
/******************************/

void version_local()
{
    static ZCONST char CompiledWith[] = "Compiled with %s%s for %s%s%s%s.\n\n";
#ifdef VMS_VERSION
    char *chrp1;
    char *chrp2;
    char buf[40];
    char vms_vers[ 16];
    int ver_maj;
#endif
#ifdef __DECC_VER
    char buf2[40];
    int  vtyp;
#endif

#ifdef VMS_VERSION
    /* Truncate the version string at the first (trailing) space. */
    strncpy( vms_vers, VMS_VERSION, sizeof( vms_vers));
    chrp1 = strchr( vms_vers, ' ');
    if (chrp1 != NULL)
        *chrp1 = '\0';

    /* Determine the major version number. */
    ver_maj = 0;
    chrp1 = strchr( &vms_vers[ 1], '.');
    for (chrp2 = &vms_vers[ 1];
     chrp2 < chrp1;
     ver_maj = ver_maj* 10+ *(chrp2++)- '0');

#endif /* def VMS_VERSION */

/*  DEC C in ANSI mode does not like "#ifdef MACRO" inside another
    macro when MACRO is equated to a value (by "#define MACRO 1").   */

    printf(CompiledWith,

#ifdef __GNUC__
      "gcc ", __VERSION__,
#else
#  if defined(DECC) || defined(__DECC) || defined (__DECC__)
      "DEC C",
#    ifdef __DECC_VER
      (sprintf(buf2, " %c%d.%d-%03d",
               ((vtyp = (__DECC_VER / 10000) % 10) == 6 ? 'T' :
                (vtyp == 8 ? 'S' : 'V')),
               __DECC_VER / 10000000,
               (__DECC_VER % 10000000) / 100000, __DECC_VER % 1000), buf2),
#    else
      "",
#    endif
#  else
#  ifdef VAXC
      "VAX C", "",
#  else
      "unknown compiler", "",
#  endif
#  endif
#endif

#ifdef VMS_VERSION
#  if defined( __alpha)
      "OpenVMS",
      (sprintf( buf, " (%s Alpha)", vms_vers), buf),
#  elif defined( __IA64) /* defined( __alpha) */
      "OpenVMS",
      (sprintf( buf, " (%s IA64)", vms_vers), buf),
#  else /* defined( __alpha) */
      (ver_maj >= 6) ? "OpenVMS" : "VMS",
      (sprintf( buf, " (%s VAX)", vms_vers), buf),
#  endif /* defined( __alpha) */
#else
      "VMS",
      "",
#endif /* def VMS_VERSION */

#ifdef __DATE__
      " on ", __DATE__
#else
      "", ""
#endif
      );

} /* end function version_local() */


/* 2004-10-08 SMS.
 * 2005-07-02 SMS.  Updated from latest Zip 3.
 *
 *       tempname() for VMS.
 *
 *    Generate a temporary Zip archive file name, near the actual
 *    destination Zip archive file, or at "tempath", if specified.
 *
 *    Using sys$parse() is probably more work than it's worth, but it
 *    should also be ODS5-safe.
 *
 *    Note that the generic method using tmpnam() (in FILEIO.C)
 *    produces "ziXXXXXX", where "XXXXXX" is the low six digits of the
 *    decimal representation of the process ID.  This method produces
 *    "ZIxxxxxxxx", where "xxxxxxxx" is the (whole) eight-digit
 *    hexadecimal representation of the process ID.  More important, it
 *    actually uses the directory part of the argument or "tempath".
 */


char *tempname( char *zip)
/* char *zip; */                /* Path name of Zip archive. */
{
    char *temp_name;            /* Return value. */
    int sts;                    /* System service status. */

    static int pid;             /* Process ID. */
    static int pid_len;         /* Returned size of process ID. */

    struct                      /* Item list for GETJPIW. */
    {
        short buf_len;          /* Buffer length. */
        short itm_cod;          /* Item code. */
        int *buf;               /* Buffer address. */
        int *ret_len;           /* Returned length. */
        int term;               /* Item list terminator. */
    } jpi_itm_lst = { sizeof( pid), JPI$_PID, &pid, &pid_len };

    /* ZI<UNIQUE> name storage. */
    static char zip_tmp_nam[ 16] = "ZI<unique>.;";

    struct FAB fab;             /* FAB structure. */
    struct NAM_STRUCT nam;      /* NAM[L] structure. */

    char exp_str[ NAM_MAXRSS+ 1];   /* Expanded name storage. */

#ifdef VMS_UNIQUE_TEMP_BY_TIME

    /* Use alternate time-based scheme to generate a unique temporary name. */
    sprintf( &zip_tmp_nam[ 2], "%08X", time( NULL));

#else /* def VMS_UNIQUE_TEMP_BY_TIME */

    /* Use the process ID to generate a unique temporary name. */
    sts = sys$getjpiw( 0, 0, 0, &jpi_itm_lst, 0, 0, 0);
    sprintf( &zip_tmp_nam[ 2], "%08X", pid);

#endif /* def VMS_UNIQUE_TEMP_BY_TIME */

    /* Smoosh the unique temporary name against the actual Zip archive
       name (or "tempath") to create the full temporary path name.
       (Truncate it at the file type to remove any file type.)
    */
    if (tempath != NULL)        /* Use "tempath", if it's been specified. */
        zip = tempath;

    /* Initialize the FAB and NAM[L], and link the NAM[L] to the FAB. */
    fab = cc$rms_fab;
    nam = CC_RMS_NAM;
    fab.FAB_NAM = &nam;

    /* Point the FAB/NAM[L] fields to the actual name and default name. */

#ifdef NAML$C_MAXRSS

    fab.fab$l_dna = (char *) -1;    /* Using NAML for default name. */
    fab.fab$l_fna = (char *) -1;    /* Using NAML for file name. */

#endif /* def NAML$C_MAXRSS */

    /* Default name = Zip archive name. */
    FAB_OR_NAM( fab, nam).FAB_OR_NAM_DNA = zip;
    FAB_OR_NAM( fab, nam).FAB_OR_NAM_DNS = strlen( zip);

    /* File name = "ZI<unique>,;". */
    FAB_OR_NAM( fab, nam).FAB_OR_NAM_FNA = zip_tmp_nam;
    FAB_OR_NAM( fab, nam).FAB_OR_NAM_FNS = strlen( zip_tmp_nam);

    nam.NAM_ESA = exp_str;      /* Expanded name (result) storage. */
    nam.NAM_ESS = NAM_MAXRSS;   /* Size of expanded name storage. */

    nam.NAM_NOP = NAM_M_SYNCHK; /* Syntax-only analysis. */

    temp_name = NULL;           /* Prepare for failure (unlikely). */
    sts = sys$parse( &fab, 0, 0);       /* Parse the name(s). */

    if ((sts& STS$M_SEVERITY) == STS$K_SUCCESS)
    {
        /* Overlay any resulting file type (typically ".ZIP") with none. */
        strcpy( nam.NAM_L_TYPE, ".;");

        /* Allocate temp name storage (as caller expects), and copy the
           (truncated) temp name into the new location.
        */
        temp_name = malloc( strlen( nam.NAM_ESA)+ 1);

        if (temp_name != NULL)
        {
            strcpy( temp_name, nam.NAM_ESA);
        }
    }
    return temp_name;
} /* tempname() for VMS. */


/* 2005-02-17 SMS.
 * 2005-07-02 SMS.  Moved into Zip 2 from Zip 3.
 *
 *       ziptyp() for VMS.
 *
 *    Generate a real Zip archive file name (exact, if it exists), using
 *    a default file name.
 *
 *    2005-02-17 SMS.  Moved to here from [-]ZIPFILE.C, to segregate
 *    better the RMS stuff.
 *
 *    Before 2005-02-17, if sys$parse() failed, ziptyp() returned a null
 *    string ("&zero", where "static char zero = '\0';").  This
 *    typically caused Zip to proceed, but then the final rename() of
 *    the temporary archive would (silently) fail (null file name, after
 *    all), leaving only the temporary archive file, and providing no
 *    warning message to the victim.  Now, when sys$parse() fails,
 *    ziptyp() returns the original string, so a later open() fails, and
 *    a relatively informative message is provided.  (A VMS-specific
 *    message could also be provided here, if desired.)
 *
 *    2005-09-16 SMS.
 *    Changed name parsing in ziptyp() to solve a problem with a
 *    search-list logical name device-directory spec for the zipfile.
 *    Previously, when the zipfile did not exist (so sys$search()
 *    failed), the expanded name was used, but as it was
 *    post-sys$search(), it was based on the _last_ member of the search
 *    list instead of the first.  Now, the expanded name from the
 *    original sys$parse() (pre-sys$search()) is retained, and it is
 *    used if sys$search() fails.  This name is based on the first
 *    member of the search list, as a user might expect.
 */

/* Default Zip archive file spec. */