human68k.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 2004-May-22 or later
  (the contents of which are also included in zip.h) for terms of use.
  If, for some reason, both of these files are missing, the Info-ZIP license
  also may be found at:  ftp://ftp.info-zip.org/pub/infozip/license.html
*/
#include "zip.h"

#include <time.h>
#include <stdio.h>
#include <dirent.h>
#ifndef UTIL
#include <sys/dos.h>
#endif

#define MATCH shmatch

#define PAD 0


#ifndef UTIL

/* Library functions not in (most) header files */

int utime OF((char *, ztimbuf *));

/* Local functions */
local char *readd OF((DIR *));

local char *readd(DIR* d)
{
   struct dirent* e = readdir(d);

   return e == NULL ? NULL : e->d_name;
}

int wild(char* w)
{
  struct _filbuf inf;
  char name[FNMAX];
  char *p;

  if (strcmp(w, "-") == 0)   /* if compressing stdin */
    return newname(w, 0, 0);
  strcpy(name, w);
  _toslash(name);

  if ((p = strrchr(name, '/')) == NULL && (p = strrchr(name, ':')) == NULL)
    p = name;
  else
    p++;
  if (_dos_lfiles (&inf, w, 0xff) < 0)
    return ZE_MISS;
  do {
    int r;

    strcpy(p, inf.name);
    r = procname(name, 0);
    if (r != ZE_OK)
      return r;
  } while (_dos_nfiles(&inf) >= 0);

  return ZE_OK;
}

int procname(n, caseflag)
char *n;                /* name to process */
int caseflag;           /* true to force case-sensitive match */
/* Process a name or sh expression to operate on (or exclude).  Return
   an error code in the ZE_ class. */
{
  char *a;              /* path and name for recursion */
  DIR *d;               /* directory stream from opendir() */
  char *e;              /* pointer to name from readd() */
  int m;                /* matched flag */
  char *p;              /* path for recursion */
  struct stat s;        /* result of stat() */
  struct zlist far *z;  /* steps through zfiles list */

  if (strcmp(n, "-") == 0)   /* if compressing stdin */
    return newname(n, 0, caseflag);
  else if (LSSTAT(n, &s))
  {
    /* Not a file or directory--search for shell expression in zip file */
    p = ex2in(n, 0, (int *)NULL);       /* shouldn't affect matching chars */
    m = 1;
    for (z = zfiles; z != NULL; z = z->nxt) {
      if (MATCH(p, z->iname, caseflag))
      {
        z->mark = pcount ? filter(z->zname, caseflag) : 1;
        if (verbose)
            fprintf(mesg, "zip diagnostic: %scluding %s\n",
               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 */
  _toslash(n);
  if ((s.st_mode & S_IFDIR) == 0)
  {
    /* add or remove name of file */
    if ((m = newname(n, 0, caseflag)) != ZE_OK)
      return m;
  } else {
    /* Add trailing / to the directory name */
    if ((p = malloc(strlen(n)+2)) == NULL)
      return ZE_MEM;
    if (strcmp(n, ".") == 0) {
      *p = '\0';  /* avoid "./" prefix and do not create zip entry */
    } else {
      strcpy(p, n);
      a = p + strlen(p);
      if (a[-1] != '/')
        strcpy(a, "/");
      if (dirnames && (m = newname(p, 1, caseflag)) != ZE_OK) {
        free((zvoid *)p);
        return m;
      }
    }
    /* recurse into directory */
    if (recurse && (d = opendir(n)) != NULL)
    {
      while ((e = readd(d)) != NULL) {
        if (strcmp(e, ".") && strcmp(e, ".."))
        {
          if ((a = malloc(strlen(p) + strlen(e) + 1)) == NULL)
          {
            closedir(d);
            free((zvoid *)p);
            return ZE_MEM;
          }
          strcat(strcpy(a, p), e);
          if ((m = procname(a, caseflag)) != ZE_OK)   /* recurse on name */
          {
            if (m == ZE_MISS)
              zipwarn("name not matched: ", a);
            else
              ziperr(m, a);
          }
          free((zvoid *)a);
        }
      }
      closedir(d);
    }
    free((zvoid *)p);
  } /* (s.st_mode & S_IFDIR) == 0) */
  return ZE_OK;
}

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 */

  /* Find starting point in name before doing malloc */
  t = (x[0] && x[1] == (char)':') ? x + 2 : x;
  while (*t == (char)'/')
    t++;

  /* Make changes, if any, to the copied name (leave original intact) */
  _toslash(t);

  if (!pathput)
    t = last(t, '/');

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

  if (dosify)
    msname(n);
  /* Returned malloc'ed name */
  if (pdosflag)
    *pdosflag = dosify;
  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 */
  if ((x = malloc(strlen(n) + 1 + PAD)) == NULL)
      return NULL;
  return strcpy(x, n);
}

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. */
{
  ztimbuf u;            /* argument for utime() */

  /* Convert DOS time to time_t format in u */
  u.actime = u.modtime = dos2unixtime(d);

  /* Set updated and accessed times of f */
  utime(f, &u);
}

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() */
  char *name;
  unsigned int len = strlen(f);
  int isstdin = !strcmp(f, "-");

  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 (isstdin) {
    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;
  }

  if (a != NULL) {
    int atr = _dos_chmod(name, -1);

    if (atr < 0)
      atr = 0x20;
    *a = ((ulg)s.st_mode << 16) | (isstdin ? 0L : (ulg)atr);
  }
  if (n != NULL)
    *n = S_ISVOL(s.st_mode) ? -2L : S_ISREG(s.st_mode) ? s.st_size : -1L;
  if (t != NULL) {
    t->atime = s.st_atime;
    t->mtime = s.st_mtime;
    t->ctime = s.st_ctime;
  }

  free(name);

  return unix2dostime(&s.st_mtime);
}

int set_extra_field(z, z_utim)
  struct zlist far *z;
  iztimes *z_utim;
  /* create extra field and change z->att if desired */
{
#ifdef USE_EF_UT_TIME
  if ((z->extra = (char *)malloc(EB_HEADSIZE+EB_UT_LEN(1))) == NULL)
    return ZE_MEM;

  z->extra[0]  = 'U';
  z->extra[1]  = 'T';
  z->extra[2]  = EB_UT_LEN(1);          /* length of data part of e.f. */
  z->extra[3]  = 0;
  z->extra[4]  = EB_UT_FL_MTIME;
  z->extra[5]  = (char)(z_utim->mtime);
  z->extra[6]  = (char)(z_utim->mtime >> 8);
  z->extra[7]  = (char)(z_utim->mtime >> 16);
  z->extra[8]  = (char)(z_utim->mtime >> 24);

  z->cext = z->ext = (EB_HEADSIZE+EB_UT_LEN(1));
  z->cextra = z->extra;

  return ZE_OK;
#else /* !USE_EF_UT_TIME */
  return (int)(z-z);
#endif /* ?USE_EF_UT_TIME */
}

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]).
 */
{
    return rmdir(d);
}

void print_period(void)
{
  fputc('.', stderr);
}

#endif /* !UTIL */


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

void version_local()
{
    static ZCONST char CompiledWith[] = "Compiled with %s%s for %s%s%s%s.\n\n";
#if 0
    char buf[40];
#endif

    printf(CompiledWith,

#ifdef __GNUC__
      "gcc ", __VERSION__,
#else
#  if 0
      "cc ", (sprintf(buf, " version %d", _RELEASE), buf),
#  else
      "unknown compiler", "",
#  endif
#endif

      "Human68k",
#ifdef __MC68020__
      " (X68030)",
#else
      " (X680x0)",
#endif

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

} /* end function version_local() */