util.c

给出了 zip 压缩算法的完整实现过程。

#if defined(ATARI) || defined(CMS_MVS)
#include <ctype.h>
/* this should be valid for all other platforms too.   (HD 11/11/95) */
  for (c = 0; c< sizeof(upper); c++) {
    upper[c] = islower(c) ? toupper(c) : c;
    lower[c] = isupper(c) ? tolower(c) : c;
  }
#else
  for (c = 0; c < sizeof(upper); c++) upper[c] = lower[c] = (uch)c;
  for (c = 'a'; c <= 'z';        c++) upper[c] = (uch)(c - 'a' + 'A');
  for (c = 'A'; c <= 'Z';        c++) lower[c] = (uch)(c - 'A' + 'a');
#endif
}
#  endif /* !OS2 */

#endif /* ?MSDOS16 */

int namecmp(string1, string2)
  ZCONST char *string1, *string2;
/* Compare the two strings ignoring case, and correctly taking into
 * account national language characters. For operating systems with
 * case sensitive file names, this function is equivalent to strcmp.
 */
{
  int d;

  for (;;)
  {
    d = (int) (uch) case_map(*string1)
      - (int) (uch) case_map(*string2);

    if (d || *string1 == 0 || *string2 == 0)
      return d;

    string1++;
    string2++;
  }
}

#ifdef EBCDIC
char *strtoasc(char *str1, ZCONST char *str2)
{
  char *old;
  old = str1;
  while (*str1++ = (char)ascii[(uch)(*str2++)]);
  return old;
}

char *strtoebc(char *str1, ZCONST char *str2)
{
  char *old;
  old = str1;
  while (*str1++ = (char)ebcdic[(uch)(*str2++)]);
  return old;
}

char *memtoasc(char *mem1, ZCONST char *mem2, unsigned len)
{
  char *old;
  old = mem1;
  while (len--)
     *mem1++ = (char)ascii[(uch)(*mem2++)];
  return old;
}

char *memtoebc(char *mem1, ZCONST char *mem2, unsigned len)
{
  char *old;
  old = mem1;
  while (len--)
     *mem1++ = (char)ebcdic[(uch)(*mem2++)];
  return old;
}
#endif /* EBCDIC */

#ifdef IZ_ISO2OEM_ARRAY
char *str_iso_to_oem(dst, src)
  ZCONST char *src;
  char *dst;
{
  char *dest_start = dst;
  while (*dst++ = (char)iso2oem[(uch)(*src++)]);
  return dest_start;
}
#endif

#ifdef IZ_OEM2ISO_ARRAY
char *str_oem_to_iso(dst, src)
  ZCONST char *src;
  char *dst;
{
  char *dest_start = dst;
  while (*dst++ = (char)oem2iso[(uch)(*src++)]);
  return dest_start;
}
#endif



/* DBCS support for Info-ZIP's zip  (mainly for japanese (-: )
 * by Yoshioka Tsuneo ([e-mail],[e-mail])
 * This code is public domain!   Date: 1998/12/20
 */
#ifdef _MBCS

char *___tmp_ptr;

int lastchar(ptr)
    ZCONST char *ptr;
{
    ZCONST char *oldptr = ptr;
    while(*ptr != '\0'){
        oldptr = ptr;
        INCSTR(ptr);
    }
    return (int)(unsigned)*oldptr;
}

unsigned char *zmbschr(str, c)
    ZCONST unsigned char *str;
    unsigned int c;
{
    while(*str != '\0'){
        if (*str == c) {return (char*)str;}
        INCSTR(str);
    }
    return NULL;
}

unsigned char *zmbsrchr(str, c)
    ZCONST unsigned char *str;
    unsigned int c;
{
    unsigned char *match = NULL;
    while(*str != '\0'){
        if (*str == c) {match = (char*)str;}
        INCSTR(str);
    }
    return match;
}
#endif /* _MBCS */



#ifndef UTIL

/*****************************************************************
 | envargs - add default options from environment to command line
 |----------------------------------------------------------------
 | Author: Bill Davidsen, original 10/13/91, revised 23 Oct 1991.
 | This program is in the public domain.
 |----------------------------------------------------------------
 | Minor program notes:
 |  1. Yes, the indirection is a tad complex
 |  2. Parenthesis were added where not needed in some cases
 |     to make the action of the code less obscure.
 ****************************************************************/

void envargs(Pargc, Pargv, envstr, envstr2)
    int *Pargc;
    char ***Pargv;
    char *envstr;
    char *envstr2;
{
    char *envptr;                     /* value returned by getenv */
    char *bufptr;                     /* copy of env info */
    int argc;                         /* internal arg count */
    register int ch;                  /* spare temp value */
    char **argv;                      /* internal arg vector */
    char **argvect;                   /* copy of vector address */

    /* see if anything in the environment */
    envptr = getenv(envstr);
    if (envptr != NULL)                                /* usual var */
        while (isspace((uch)*envptr))      /* we must discard leading spaces */
            envptr++;
    if (envptr == NULL || *envptr == '\0')
        if ((envptr = getenv(envstr2)) != NULL)                 /* alternate */
            while (isspace((uch)*envptr))
                envptr++;
    if (envptr == NULL || *envptr == '\0')
        return;

    /* count the args so we can allocate room for them */
    argc = count_args(envptr);
    bufptr = malloc(1 + strlen(envptr));
    if (bufptr == NULL)
        ziperr(ZE_MEM, "Can't get memory for arguments");
    strcpy(bufptr, envptr);

    /* allocate a vector large enough for all args */
    argv = (char **)malloc((argc + *Pargc + 1) * sizeof(char *));
    if (argv == NULL) {
        free(bufptr);
        ziperr(ZE_MEM, "Can't get memory for arguments");
    }
    argvect = argv;

    /* copy the program name first, that's always true */
    *(argv++) = *((*Pargv)++);

    /* copy the environment args first, may be changed */
    do {
#if defined(AMIGA) || defined(UNIX)
        if (*bufptr == '"') {
            char *argstart = ++bufptr;
            *(argv++) = argstart;
            for (ch = *bufptr; ch != '\0' && ch != '\"';
                 ch = *PREINCSTR(bufptr))
                if (ch == '\\' && bufptr[1] != '\0')
                    ++bufptr;               /* skip to char after backslash */
            if (ch != '\0')                       /* overwrite trailing '"' */
                *(bufptr++) = '\0';

            /* remove escape characters */
            while ((argstart = MBSCHR(argstart, '\\')) != NULL) {
                strcpy(argstart, argstart + 1);
                if (*argstart)
                    ++argstart;
            }
        } else {
            *(argv++) = bufptr;
            while ((ch = *bufptr) != '\0' && !isspace((uch)ch)) INCSTR(bufptr);
            if (ch != '\0') *(bufptr++) = '\0';
        }
#else
#  ifdef WIN32
        /* We do not support backslash-quoting of quotes in quoted */
        /* strings under Win32, because backslashes are directory  */
        /* separators and double quotes are illegal in filenames.  */
        if (*bufptr == '"') {
            *(argv++) = ++bufptr;
            while ((ch = *bufptr) != '\0' && ch != '\"') INCSTR(bufptr);
            if (ch != '\0') *(bufptr++) = '\0';
        } else {
            *(argv++) = bufptr;
            while ((ch = *bufptr) != '\0' && !isspace((uch)ch)) INCSTR(bufptr);
            if (ch != '\0') *(bufptr++) = '\0';
        }
#  else
        *(argv++) = bufptr;
        while ((ch = *bufptr) != '\0' && !isspace((uch)ch)) INCSTR(bufptr);
        if (ch != '\0') *(bufptr++) = '\0';
#  endif
#endif /* ?(AMIGA || UNIX) */
        while ((ch = *bufptr) != '\0' && isspace((uch)ch)) INCSTR(bufptr);
    } while (ch);

    /* now save old argc and copy in the old args */
    argc += *Pargc;
    while (--(*Pargc)) *(argv++) = *((*Pargv)++);

    /* finally, add a NULL after the last arg, like UNIX */
    *argv = NULL;

    /* save the values and return */
    *Pargv = argvect;
    *Pargc = argc;
}

static int count_args(s)
char *s;
{
    int count = 0;
    char ch;

    do {
        /* count and skip args */
        ++count;
#if defined(AMIGA) || defined(UNIX)
        if (*s == '\"') {
            for (ch = *PREINCSTR(s); ch != '\0' && ch != '\"';
                 ch = *PREINCSTR(s))
                if (ch == '\\' && s[1] != '\0')
                    INCSTR(s);
            if (*s) INCSTR(s);  /* trailing quote */
        } else
            while ((ch = *s) != '\0' && !isspace((uch)ch)) INCSTR(s);
#else
#  ifdef WIN32
        if (*s == '\"') {
            ++s;                /* leading quote */
            while ((ch = *s) != '\0' && ch != '\"') INCSTR(s);
            if (*s) INCSTR(s);  /* trailing quote */
        } else
            while ((ch = *s) != '\0' && !isspace((uch)ch)) INCSTR(s);
#  else
        while ((ch = *s) != '\0' && !isspace((uch)ch)) INCSTR(s);
#  endif
#endif /* ?(AMIGA || UNIX) */
        while ((ch = *s) != '\0' && isspace((uch)ch)) INCSTR(s);
    } while (ch);

    return(count);
}



/* Extended argument processing -- by Rich Wales
 * This function currently deals only with the MKS shell, but could be
 * extended later to understand other conventions.
 *
 * void expand_args(int *argcp, char ***argvp)
 *
 *    Substitutes the extended command line argument list produced by
 *    the MKS Korn Shell in place of the command line info from DOS.
 *
 *    The MKS shell gets around DOS's 128-byte limit on the length of
 *    a command line by passing the "real" command line in the envi-
 *    ronment.  The "real" arguments are flagged by prepending a tilde
 *    (~) to each one.
 *
 *    This "expand_args" routine creates a new argument list by scanning
 *    the environment from the beginning, looking for strings begin-
 *    ning with a tilde character.  The new list replaces the original
 *    "argv" (pointed to by "argvp"), and the number of arguments
 *    in the new list replaces the original "argc" (pointed to by
 *    "argcp").
 */
void expand_args(argcp, argvp)
      int *argcp;
      char ***argvp;
{
#ifdef DOS

/* Do NEVER include (re)definiton of `environ' variable with any version
   of MSC or BORLAND/Turbo C. These compilers supply an incompatible
   definition in <stdlib.h>.  */
#if defined(__GO32__) || defined(__EMX__)
      extern char **environ;          /* environment */
#endif /* __GO32__ || __EMX__ */
      char        **envp;             /* pointer into environment */
      char        **newargv;          /* new argument list */
      char        **argp;             /* pointer into new arg list */
      int           newargc;          /* new argument count */

      /* sanity check */
      if (environ == NULL
          || argcp == NULL
          || argvp == NULL || *argvp == NULL)
              return;
      /* find out how many environment arguments there are */
      for (envp = environ, newargc = 0;
           *envp != NULL && (*envp)[0] == '~';
           envp++, newargc++) ;
      if (newargc == 0)
              return;                 /* no environment arguments */
      /* set up new argument list */
      newargv = (char **) malloc(sizeof(char **) * (newargc+1));
      if (newargv == NULL)
              return;                 /* malloc failed */
      for (argp = newargv, envp = environ;
           *envp != NULL && (*envp)[0] == '~';
           *argp++ = &(*envp++)[1]) ;
      *argp = NULL;                   /* null-terminate the list */
      /* substitute new argument list in place of old one */
      *argcp = newargc;
      *argvp = newargv;
#else /* !DOS */
      if (argcp || argvp) return;
#endif /* ?DOS */
}

#endif /* UTIL */

#ifdef DEBUGNAMES
#undef free
int Free(x)
void *x;
{
    if (x == (void *) 0xdeadbeef)
        exit(-1);
    free(x);
    return 0;
}

int printnames()
{
     struct zlist far *z;

     for (z = zfiles; z != NULL; z = z->nxt)
           fprintf(stderr, "%s %s %s %p %p %p %08x %08x %08x\n",
                            z->name, z->zname, z->iname,
                            z->name, z->zname, z->iname,
                            *((int *) z->name), *((int *) z->zname),
                            *((int *) z->iname));
     return 0;
}

#endif /* DEBUGNAMES */