unix.c

给出了 zip 压缩算法的完整实现过程。

    t->mtime = s.st_mtime;
    t->ctime = t->mtime;   /* best guess, (s.st_ctime: last status change!!) */
  }

  return unix2dostime(&s.st_mtime);
}


#ifndef QLZIP /* QLZIP Unix2QDOS cross-Zip supplies an extended variant */

int set_extra_field(z, z_utim)
  struct zlist far *z;
  iztimes *z_utim;
  /* store full data in local header but just modification time stamp info
     in central header */
{
  struct stat s;
  char *name;
  int len = strlen(z->name);

  /* For the full sized UT local field including the UID/GID fields, we
   * have to stat the file again. */

  if ((name = malloc(len + 1)) == NULL) {
    ZIPERR(ZE_MEM, "set_extra_field");
  }
  strcpy(name, z->name);
  if (name[len - 1] == '/')
    name[len - 1] = '\0';
  /* not all systems allow stat'ing a file with / appended */
  if (LSSTAT(name, &s)) {
    free(name);
    return ZE_OPEN;
  }
  free(name);

#define EB_L_UT_SIZE    (EB_HEADSIZE + EB_UT_LEN(2))
#define EB_C_UT_SIZE    (EB_HEADSIZE + EB_UT_LEN(1))
#define EB_L_UX2_SIZE   (EB_HEADSIZE + EB_UX2_MINLEN)
#define EB_C_UX2_SIZE   EB_HEADSIZE
#define EF_L_UNIX_SIZE  (EB_L_UT_SIZE + EB_L_UX2_SIZE)
#define EF_C_UNIX_SIZE  (EB_C_UT_SIZE + EB_C_UX2_SIZE)

  if ((z->extra = (char *)malloc(EF_L_UNIX_SIZE)) == NULL)
    return ZE_MEM;
  if ((z->cextra = (char *)malloc(EF_C_UNIX_SIZE)) == NULL)
    return ZE_MEM;

  z->extra[0]  = 'U';
  z->extra[1]  = 'T';
  z->extra[2]  = (char)EB_UT_LEN(2);    /* length of data part of local e.f. */
  z->extra[3]  = 0;
  z->extra[4]  = EB_UT_FL_MTIME | EB_UT_FL_ATIME;    /* st_ctime != creation */
  z->extra[5]  = (char)(s.st_mtime);
  z->extra[6]  = (char)(s.st_mtime >> 8);
  z->extra[7]  = (char)(s.st_mtime >> 16);
  z->extra[8]  = (char)(s.st_mtime >> 24);
  z->extra[9]  = (char)(s.st_atime);
  z->extra[10] = (char)(s.st_atime >> 8);
  z->extra[11] = (char)(s.st_atime >> 16);
  z->extra[12] = (char)(s.st_atime >> 24);
  z->extra[13] = 'U';
  z->extra[14] = 'x';
  z->extra[15] = (char)EB_UX2_MINLEN;   /* length of data part of local e.f. */
  z->extra[16] = 0;
  z->extra[17] = (char)(s.st_uid);
  z->extra[18] = (char)(s.st_uid >> 8);
  z->extra[19] = (char)(s.st_gid);
  z->extra[20] = (char)(s.st_gid >> 8);
  z->ext = EF_L_UNIX_SIZE;

  memcpy(z->cextra, z->extra, EB_C_UT_SIZE);
  z->cextra[EB_LEN] = (char)EB_UT_LEN(1);
  memcpy(z->cextra+EB_C_UT_SIZE, z->extra+EB_L_UT_SIZE, EB_C_UX2_SIZE);
  z->cextra[EB_LEN+EB_C_UT_SIZE] = 0;
  z->cext = EF_C_UNIX_SIZE;

#if 0  /* UID/GID presence is now signaled by central EF_IZUNIX2 field ! */
  /* lower-middle external-attribute byte (unused until now):
   *   high bit        => (have GMT mod/acc times) >>> NO LONGER USED! <<<
   *   second-high bit => have Unix UID/GID info
   * NOTE: The high bit was NEVER used in any official Info-ZIP release,
   *       but its future use should be avoided (if possible), since it
   *       was used as "GMT mod/acc times local extra field" flags in Zip beta
   *       versions 2.0j up to 2.0v, for about 1.5 years.
   */
  z->atx |= 0x4000;
#endif /* never */
  return ZE_OK;
}

#endif /* !QLZIP */


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]).
 */
{
# ifdef NO_RMDIR
    /* 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;

    sprintf(s, "IFS=\" \t\n\" /bin/rmdir %s 2>/dev/null", d);
    r = system(s);
    free(s);
    return r;
# else /* !NO_RMDIR */
    return rmdir(d);
# endif /* ?NO_RMDIR */
}

#endif /* !UTIL */


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

#if defined(__NetBSD__) || defined(__FreeBSD__) || defined(__386BSD__) || \
    defined(__OpenBSD__) || defined(__bsdi__)
#include <sys/param.h> /* for the BSD define */
/* if we have something newer than NET/2 we'll use uname(3) */
#if (BSD > 199103)
#include <sys/utsname.h>
#endif /* BSD > 199103 */
#endif /* __{Net,Free,Open,386}BSD__ || __bsdi__ */

void version_local()
{
#ifdef __GNUC__
#  ifdef NX_CURRENT_COMPILER_RELEASE
    char compiler_name[80];
#  endif
#else
#  if (defined( __SUNPRO_C))
    char compiler_name[33];
#  else
#    if (defined( __HP_cc))
    char compiler_name[33];
#    else
#      if (defined( __DECC_VER))
    char compiler_name[33];
    int compiler_typ;
#      else
#        if ((defined(CRAY) || defined(cray)) && defined(_RELEASE))
    char compiler_name[40];
#        endif
#      endif
#    endif
#  endif
#endif

#ifdef BSD
# if (BSD > 199103)
    struct utsname u;
    char os_name[40];
# else
# if defined(__NETBSD__))
    static ZCONST char *netbsd[] = { "_ALPHA", "", "A", "B" };
    char os_name[40];
# endif /* __NETBSD__ */
# endif /* BSD > 199103 */
#else /* !BSD */
#if ((defined(CRAY) || defined(cray)) && defined(_UNICOS))
    char os_name[40];
#endif /* (CRAY && defined(_UNICOS)) */
#endif /* ?BSD */

/* Define the compiler name and version string */
#ifdef __GNUC__
#  ifdef NX_CURRENT_COMPILER_RELEASE
    sprintf(compiler_name, "NeXT DevKit %d.%02d (gcc " __VERSION__ ")",
        NX_CURRENT_COMPILER_RELEASE/100, NX_CURRENT_COMPILER_RELEASE%100);
#    define COMPILER_NAME compiler_name
#  else
#    define COMPILER_NAME "gcc " __VERSION__
#  endif
#else /* !__GNUC__ */
#  if defined(__SUNPRO_C)
    sprintf( compiler_name, "Sun C version %x", __SUNPRO_C);
#    define COMPILER_NAME compiler_name
#  else
#    if (defined( __HP_cc))
    if ((__HP_cc% 100) == 0)
    {
      sprintf( compiler_name, "HP C version A.%02d.%02d",
       (__HP_cc/ 10000), ((__HP_cc% 10000)/ 100));
    }
    else
    {
      sprintf( compiler_name, "HP C version A.%02d.%02d.%02d",
       (__HP_cc/ 10000), ((__HP_cc% 10000)/ 100), (__HP_cc% 100));
    }
#      define COMPILER_NAME compiler_name
#    else
#      if (defined( __DECC_VER))
    sprintf( compiler_name, "DEC C version %c%d.%d-%03d",
     ((compiler_typ = (__DECC_VER / 10000) % 10) == 6 ? 'T' :
     (compiler_typ == 8 ? 'S' : 'V')),
     __DECC_VER / 10000000,
     (__DECC_VER % 10000000) / 100000, __DECC_VER % 1000);
#        define COMPILER_NAME compiler_name
#      else
#        if ((defined(CRAY) || defined(cray)) && defined(_RELEASE))
    sprintf(compiler_name, "cc version %d", _RELEASE);
#          define COMPILER_NAME compiler_name
#        else
#          ifdef __VERSION__
#            define COMPILER_NAME "cc " __VERSION__
#          else
#            define COMPILER_NAME "cc"
#          endif
#        endif
#      endif
#    endif
#  endif
#endif /* ?__GNUC__ */


/* Define the name to use for the OS we're compiling on */
#if defined(sgi) || defined(__sgi)
#  define OS_NAME "Silicon Graphics IRIX"
#else
#ifdef sun
#  ifdef sparc
#    ifdef __SVR4
#      define OS_NAME "Sun SPARC/Solaris"
#    else /* may or may not be SunOS */
#      define OS_NAME "Sun SPARC"
#    endif
#  else
#  if defined(sun386) || defined(i386)
#    define OS_NAME "Sun 386i"
#  else
#  if defined(mc68020) || defined(__mc68020__)
#    define OS_NAME "Sun 3"
#  else /* mc68010 or mc68000:  Sun 2 or earlier */
#    define OS_NAME "Sun 2"
#  endif
#  endif
#  endif
#else
#ifdef __hpux
#  define OS_NAME "HP-UX"
#else
#ifdef __osf__
#  define OS_NAME "DEC OSF/1"
#else
#ifdef _AIX
#  define OS_NAME "IBM AIX"
#else
#ifdef aiws
#  define OS_NAME "IBM RT/AIX"
#else
#if defined(CRAY) || defined(cray)
#  ifdef _UNICOS
    sprintf(os_name, "Cray UNICOS release %d", _UNICOS);
#    define OS_NAME os_name
#  else
#    define OS_NAME "Cray UNICOS"
#  endif
#else
#if defined(uts) || defined(UTS)
#  define OS_NAME "Amdahl UTS"
#else
#ifdef NeXT
#  ifdef mc68000
#    define OS_NAME "NeXTStep/black"
#  else
#    define OS_NAME "NeXTStep for Intel"
#  endif
#else
#if defined(linux) || defined(__linux__)
#  ifdef __ELF__
#    define OS_NAME "Linux ELF"
#  else
#    define OS_NAME "Linux a.out"
#  endif
#else
#ifdef MINIX
#  define OS_NAME "Minix"
#else
#ifdef M_UNIX
#  define OS_NAME "SCO Unix"
#else
#ifdef M_XENIX
#  define OS_NAME "SCO Xenix"
#else
#ifdef BSD
# if (BSD > 199103)
#    define OS_NAME os_name
    uname(&u);
    sprintf(os_name, "%s %s", u.sysname, u.release);
# else
# ifdef __NetBSD__
#   define OS_NAME os_name
#   ifdef NetBSD0_8
      sprintf(os_name, "NetBSD 0.8%s", netbsd[NetBSD0_8]);
#   else
#   ifdef NetBSD0_9
      sprintf(os_name, "NetBSD 0.9%s", netbsd[NetBSD0_9]);
#   else
#   ifdef NetBSD1_0
      sprintf(os_name, "NetBSD 1.0%s", netbsd[NetBSD1_0]);
#   endif /* NetBSD1_0 */
#   endif /* NetBSD0_9 */
#   endif /* NetBSD0_8 */
# else
# ifdef __FreeBSD__
#    define OS_NAME "FreeBSD 1.x"
# else
# ifdef __bsdi__
#    define OS_NAME "BSD/386 1.0"
# else
# ifdef __386BSD__
#    define OS_NAME "386BSD"
# else
#    define OS_NAME "Unknown BSD"
# endif /* __386BSD__ */
# endif /* __bsdi__ */
# endif /* FreeBSD */
# endif /* NetBSD */
# endif /* BSD > 199103 */
#else
#ifdef __CYGWIN__
#  define OS_NAME "Cygwin"
#else
#if defined(i686) || defined(__i686) || defined(__i686__)
#  define OS_NAME "Intel 686"
#else
#if defined(i586) || defined(__i586) || defined(__i586__)
#  define OS_NAME "Intel 586"
#else
#if defined(i486) || defined(__i486) || defined(__i486__)
#  define OS_NAME "Intel 486"
#else
#if defined(i386) || defined(__i386) || defined(__i386__)
#  define OS_NAME "Intel 386"
#else
#ifdef pyr
#  define OS_NAME "Pyramid"
#else
#if defined(ultrix) || defined(__ultrix)
#  if defined(mips) || defined(__mips)
#    define OS_NAME "DEC/MIPS"
#  else
#  if defined(vax) || defined(__vax)
#    define OS_NAME "DEC/VAX"
#  else /* __alpha? */
#    define OS_NAME "DEC/Alpha"
#  endif
#  endif
#else
#ifdef gould
#  define OS_NAME "Gould"
#else
#ifdef MTS
#  define OS_NAME "MTS"
#else
#ifdef __convexc__
#  define OS_NAME "Convex"
#else
#ifdef __QNX__
#  define OS_NAME "QNX 4"
#else
#ifdef __QNXNTO__
#  define OS_NAME "QNX Neutrino"
#else
#ifdef __APPLE__
#  define OS_NAME "Mac OS X"
#else
#  define OS_NAME "Unknown"
#endif /* Apple */
#endif /* QNX Neutrino */
#endif /* QNX 4 */
#endif /* Convex */
#endif /* MTS */
#endif /* Gould */
#endif /* DEC */
#endif /* Pyramid */
#endif /* 386 */
#endif /* 486 */
#endif /* 586 */
#endif /* 686 */
#endif /* Cygwin */
#endif /* BSD */
#endif /* SCO Xenix */
#endif /* SCO Unix */
#endif /* Minix */
#endif /* Linux */
#endif /* NeXT */
#endif /* Amdahl */
#endif /* Cray */
#endif /* RT/AIX */
#endif /* AIX */
#endif /* OSF/1 */
#endif /* HP-UX */
#endif /* Sun */
#endif /* SGI */


/* Define the compile date string */
#ifdef __DATE__
#  define COMPILE_DATE " on " __DATE__
#else
#  define COMPILE_DATE ""
#endif

    printf("Compiled with %s for Unix (%s)%s.\n\n",
           COMPILER_NAME, OS_NAME, COMPILE_DATE);

} /* end function version_local() */