zlib的应用

主要分析应用的demo，有空再分析底层实现

官方demo位于zlib-1.2.11contribminizip

对官方代码的分析

/*
   miniunz.c
   Version 1.1, February 14h, 2010
   sample part of the MiniZip project - ( http://www.winimage.com/zLibDll/minizip.html )

         Copyright (C) 1998-2010 Gilles Vollant (minizip) ( http://www.winimage.com/zLibDll/minizip.html )

         Modifications of Unzip for Zip64
         Copyright (C) 2007-2008 Even Rouault

         Modifications for Zip64 support on both zip and unzip
         Copyright (C) 2009-2010 Mathias Svensson ( http://result42.com )
*/

#if (!defined(_WIN32)) && (!defined(WIN32)) && (!defined(__APPLE__))
        #ifndef __USE_FILE_OFFSET64
                #define __USE_FILE_OFFSET64
        #endif
        #ifndef __USE_LARGEFILE64
                #define __USE_LARGEFILE64
        #endif
        #ifndef _LARGEFILE64_SOURCE
                #define _LARGEFILE64_SOURCE
        #endif
        #ifndef _FILE_OFFSET_BIT
                #define _FILE_OFFSET_BIT 64
        #endif
#endif

#ifdef __APPLE__
// In darwin and perhaps other BSD variants off_t is a 64 bit value, hence no need for specific 64 bit functions
#define FOPEN_FUNC(filename, mode) fopen(filename, mode)
#define FTELLO_FUNC(stream) ftello(stream)
#define FSEEKO_FUNC(stream, offset, origin) fseeko(stream, offset, origin)
#else
#define FOPEN_FUNC(filename, mode) fopen64(filename, mode)
#define FTELLO_FUNC(stream) ftello64(stream)
#define FSEEKO_FUNC(stream, offset, origin) fseeko64(stream, offset, origin)
#endif


#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <errno.h>
#include <fcntl.h>

#ifdef _WIN32
# include <direct.h>
# include <io.h>
#else
# include <unistd.h>
# include <utime.h>
#endif


#include "unzip.h"

#define CASESENSITIVITY (0)
#define WRITEBUFFERSIZE (8192)
#define MAXFILENAME (256)

#ifdef _WIN32
#define USEWIN32IOAPI
#include "iowin32.h"
#endif
/*
  mini unzip, demo of unzip package

  usage :
  Usage : miniunz [-exvlo] file.zip [file_to_extract] [-d extractdir]

  list the file in the zipfile, and print the content of FILE_ID.ZIP or README.TXT
    if it exists
*/


/* change_file_date : change the date/time of a file
    filename : the filename of the file where date/time must be modified
    dosdate : the new date at the MSDos format (4 bytes)
    tmu_date : the SAME new date at the tm_unz format */
void change_file_date(filename,dosdate,tmu_date)
    const char *filename;
    uLong dosdate;
    tm_unz tmu_date;
{
#ifdef _WIN32
  HANDLE hFile;
  FILETIME ftm,ftLocal,ftCreate,ftLastAcc,ftLastWrite;

  hFile = CreateFileA(filename,GENERIC_READ | GENERIC_WRITE,
                      0,NULL,OPEN_EXISTING,0,NULL);
  GetFileTime(hFile,&ftCreate,&ftLastAcc,&ftLastWrite);
  DosDateTimeToFileTime((WORD)(dosdate>>16),(WORD)dosdate,&ftLocal);
  LocalFileTimeToFileTime(&ftLocal,&ftm);
  SetFileTime(hFile,&ftm,&ftLastAcc,&ftm);
  CloseHandle(hFile);
#else
#ifdef unix || __APPLE__
  struct utimbuf ut;
  struct tm newdate;
  newdate.tm_sec = tmu_date.tm_sec;
  newdate.tm_min=tmu_date.tm_min;
  newdate.tm_hour=tmu_date.tm_hour;
  newdate.tm_mday=tmu_date.tm_mday;
  newdate.tm_mon=tmu_date.tm_mon;
  if (tmu_date.tm_year > 1900)
      newdate.tm_year=tmu_date.tm_year - 1900;
  else
      newdate.tm_year=tmu_date.tm_year ;
  newdate.tm_isdst=-1;

  ut.actime=ut.modtime=mktime(&newdate);
  utime(filename,&ut);
#endif
#endif
}


/* mymkdir and change_file_date are not 100 % portable
   As I don't know well Unix, I wait feedback for the unix portion */

int mymkdir(dirname)
    const char* dirname;
{
    int ret=0;
#ifdef _WIN32
    ret = _mkdir(dirname);
#elif unix
    ret = mkdir (dirname,0775);
#elif __APPLE__
    ret = mkdir (dirname,0775);
#endif
    return ret;
}

int makedir (newdir)
    char *newdir;
{
  char *buffer ;
  char *p;
  int  len = (int)strlen(newdir);

  if (len <= 0)
    return 0;

  buffer = (char*)malloc(len+1);
        if (buffer==NULL)
        {
                printf("Error allocating memory
");
                return UNZ_INTERNALERROR;
        }
  strcpy(buffer,newdir);

  if (buffer[len-1] == '/') {
    buffer[len-1] = '';
  }
  if (mymkdir(buffer) == 0)
    {
      free(buffer);
      return 1;
    }

  p = buffer+1;
  while (1)
    {
      char hold;

      while(*p && *p != '\' && *p != '/')
        p++;
      hold = *p;
      *p = 0;
      if ((mymkdir(buffer) == -1) && (errno == ENOENT))
        {
          printf("couldn't create directory %s
",buffer);
          free(buffer);
          return 0;
        }
      if (hold == 0)
        break;
      *p++ = hold;
    }
  free(buffer);
  return 1;
}

void do_banner()
{
    printf("MiniUnz 1.01b, demo of zLib + Unz package written by Gilles Vollant
");
    printf("more info at http://www.winimage.com/zLibDll/unzip.html

");
}

void do_help()
{
    printf("Usage : miniunz [-e] [-x] [-v] [-l] [-o] [-p password] file.zip [file_to_extr.] [-d extractdir]

" 
           "  -e  Extract without pathname (junk paths)
" 
           "  -x  Extract with pathname
" 
           "  -v  list files
" 
           "  -l  list files
" 
           "  -d  directory to extract into
" 
           "  -o  overwrite files without prompting
" 
           "  -p  extract crypted file using password

");
}

void Display64BitsSize(ZPOS64_T n, int size_char)
{
  /* to avoid compatibility problem , we do here the conversion */
  char number[21];
  int offset=19;
  int pos_string = 19;
  number[20]=0;
  for (;;) {
      number[offset]=(char)((n%10)+'0');
      if (number[offset] != '0')
          pos_string=offset;
      n/=10;
      if (offset==0)
          break;
      offset--;
  }
  {
      int size_display_string = 19-pos_string;
      while (size_char > size_display_string)
      {
          size_char--;
          printf(" ");
      }
  }

  printf("%s",&number[pos_string]);
}

int do_list(uf)
    unzFile uf;
{
    uLong i;
    unz_global_info64 gi;
    int err;

    err = unzGetGlobalInfo64(uf,&gi);
    if (err!=UNZ_OK)
        printf("error %d with zipfile in unzGetGlobalInfo 
",err);
    printf("  Length  Method     Size Ratio   Date    Time   CRC-32     Name
");
    printf("  ------  ------     ---- -----   ----    ----   ------     ----
");
    for (i=0;i<gi.number_entry;i++)
    {
        char filename_inzip[256];
        unz_file_info64 file_info;
        uLong ratio=0;
        const char *string_method;
        char charCrypt=' ';
        err = unzGetCurrentFileInfo64(uf,&file_info,filename_inzip,sizeof(filename_inzip),NULL,0,NULL,0);
        if (err!=UNZ_OK)
        {
            printf("error %d with zipfile in unzGetCurrentFileInfo
",err);
            break;
        }
        if (file_info.uncompressed_size>0)
            ratio = (uLong)((file_info.compressed_size*100)/file_info.uncompressed_size);

        /* display a '*' if the file is crypted */
        if ((file_info.flag & 1) != 0)
            charCrypt='*';

        if (file_info.compression_method==0)
            string_method="Stored";
        else
        if (file_info.compression_method==Z_DEFLATED)
        {
            uInt iLevel=(uInt)((file_info.flag & 0x6)/2);
            if (iLevel==0)
              string_method="Defl:N";
            else if (iLevel==1)
              string_method="Defl:X";
            else if ((iLevel==2) || (iLevel==3))
              string_method="Defl:F"; /* 2:fast , 3 : extra fast*/
        }
        else
        if (file_info.compression_method==Z_BZIP2ED)
        {
              string_method="BZip2 ";
        }
        else
            string_method="Unkn. ";

        Display64BitsSize(file_info.uncompressed_size,7);
        printf("  %6s%c",string_method,charCrypt);
        Display64BitsSize(file_info.compressed_size,7);
        printf(" %3lu%%  %2.2lu-%2.2lu-%2.2lu  %2.2lu:%2.2lu  %8.8lx   %s
",
                ratio,
                (uLong)file_info.tmu_date.tm_mon + 1,
                (uLong)file_info.tmu_date.tm_mday,
                (uLong)file_info.tmu_date.tm_year % 100,
                (uLong)file_info.tmu_date.tm_hour,(uLong)file_info.tmu_date.tm_min,
                (uLong)file_info.crc,filename_inzip);
        if ((i+1)<gi.number_entry)
        {
            err = unzGoToNextFile(uf);
            if (err!=UNZ_OK)
            {
                printf("error %d with zipfile in unzGoToNextFile
",err);
                break;
            }
        }
    }

    return 0;
}

/***
popt_extract_without_path : 解压的时候是否需要中间的路径
**/
int do_extract_currentfile(uf,popt_extract_without_path,popt_overwrite,password)
    unzFile uf;
    const int* popt_extract_without_path;
    int* popt_overwrite;
    const char* password;
{
    char filename_inzip[256];
    char* filename_withoutpath;
    char* p;
    int err=UNZ_OK;
    FILE *fout=NULL;
    void* buf;
    uInt size_buf;

    unz_file_info64 file_info;
    uLong ratio=0;
    err = unzGetCurrentFileInfo64(uf,&file_info,filename_inzip,sizeof(filename_inzip),NULL,0,NULL,0);//filename_inzip 得到uf内部的文件名

    if (err!=UNZ_OK)
    {
        printf("error %d with zipfile in unzGetCurrentFileInfo
",err);
        return err;
    }

    size_buf = WRITEBUFFERSIZE;
    buf = (void*)malloc(size_buf);
    if (buf==NULL)
    {
        printf("Error allocating memory
");
        return UNZ_INTERNALERROR;
    }

    p = filename_withoutpath = filename_inzip;
    while ((*p) != '')
    {
        if (((*p)=='/') || ((*p)=='\'))
            filename_withoutpath = p+1;//得到最底层的文件名
        p++;
    }

    if ((*filename_withoutpath)=='')//如果底层文件名是一个目录，那么就创建目录
    {
        if ((*popt_extract_without_path)==0)
        {
            printf("creating directory: %s
",filename_inzip);
            mymkdir(filename_inzip);
        }
    }
    else
    {
        const char* write_filename;
        int skip=0;

        if ((*popt_extract_without_path)==0)
            write_filename = filename_inzip;//包含中间路径
        else
            write_filename = filename_withoutpath;//不包含中间路径

        err = unzOpenCurrentFilePassword(uf,password);//打开当前内部文件
        if (err!=UNZ_OK)
        {
            printf("error %d with zipfile in unzOpenCurrentFilePassword
",err);
        }

        if (((*popt_overwrite)==0) && (err==UNZ_OK))//设置为重写，并且打开成功
        {
            char rep=0;
            FILE* ftestexist;
            ftestexist = FOPEN_FUNC(write_filename,"rb");
            if (ftestexist!=NULL)//已经存在这个解压出的文件，会不停询问是否覆盖，直到得到确切答案
            {
                fclose(ftestexist);
                do
                {
                    char answer[128];
                    int ret;

                    printf("The file %s exists. Overwrite ? [y]es, [n]o, [A]ll: ",write_filename);
                    ret = scanf("%1s",answer);
                    if (ret != 1)
                    {
                       exit(EXIT_FAILURE);
                    }
                    rep = answer[0] ;
                    if ((rep>='a') && (rep<='z'))
                        rep -= 0x20;
                }
                while ((rep!='Y') && (rep!='N') && (rep!='A'));
            }

            if (rep == 'N')
                skip = 1;

            if (rep == 'A')
                *popt_overwrite=1;//设置popt_overwrite为全部覆盖
        }

        if ((skip==0) && (err==UNZ_OK))//覆盖
        {
            fout=FOPEN_FUNC(write_filename,"wb");
            /* some zipfile don't contain directory alone before file */
            if ((fout==NULL) && ((*popt_extract_without_path)==0) &&
                                (filename_withoutpath!=(char*)filename_inzip))
            {
                //FOPEN_FUNC(write_filename,"wb")本身是创建文件，可是如果没有现成的上级目录，创建不会成功，所以说明不存在对应的目录
                //filename_inzip,filename_withoutpath,write_filename是同一个字符串的不同位置，所以可以任意操作其中一个
                char c=*(filename_withoutpath-1);
                *(filename_withoutpath-1)='';//修改了最后一个路径符为结束符，就是一个路径
                makedir(write_filename);//创建路径
                *(filename_withoutpath-1)=c;//还原原来的路径
                fout=FOPEN_FUNC(write_filename,"wb");
            }

            if (fout==NULL)
            {
                printf("error opening %s
",write_filename);
            }
        }

        if (fout!=NULL)
        {
            printf(" extracting: %s
",write_filename);

            do
            {
                err = unzReadCurrentFile(uf,buf,size_buf);//8K的内存
                if (err<0)
                {
                    printf("error %d with zipfile in unzReadCurrentFile
",err);
                    break;
                }
                if (err>0)
                    if (fwrite(buf,err,1,fout)!=1)
                    {
                        printf("error in writing extracted file
");
                        err=UNZ_ERRNO;
                        break;
                    }
            }
            while (err>0);
            if (fout)
                    fclose(fout);

            if (err==0)//结束
                change_file_date(write_filename,file_info.dosDate,
                                 file_info.tmu_date);//还原创建时间
        }

        if (err==UNZ_OK)
        {
            err = unzCloseCurrentFile (uf);
            if (err!=UNZ_OK)
            {
                printf("error %d with zipfile in unzCloseCurrentFile
",err);
            }
        }
        else
            unzCloseCurrentFile(uf); /* don't lose the error */
    }

    free(buf);
    return err;
}
/**
打开一个ZIP文件后，
需要先使用unzGetGlobalInfo64来取得该文件的一些信息，来了解这个压缩包里一共包含了多少个文件，等等。
目前我们用得着的就是这个文件数目。
然后开始遍历ZIP中的文件，初始时自动会定位在第一个文件，以后处理完一个后用unzGoToNextFile来跳到下一个文件。

对于每个内部文件，可用unzGetCurrentFileInfo64来查内部文件名。

这个文件名和刚才zipOpenNewFileInZip的第二个参数是一样的形式，所以有可能包含路径。
也有可能会以路径分隔符（/）结尾，表明这是个目录项（其实压缩操作的时候也可以针对目录写入这样的内部文件，上面没有做）。
所以接下来要根据情况创建（多级）目录。
unzGetCurrentFileInfo64的第三个参数是unz_file_info64结构，其中也有一项包含了dosDate信息，可以还原文件时间。

对于非目录的内部文件，用 unzOpenCurrentFile，打开，然后unzReadCurrentFile读取文件内容，写入到真实文件中。
unzReadCurrentFile返回 0 表示文件读取结束。


uf ：zip文件对象
opt_extract_without_path ：0或者1
opt_overwrite ：0或者1
password ：密码

**/
int do_extract(uf,opt_extract_without_path,opt_overwrite,password)
    unzFile uf;
    int opt_extract_without_path;
    int opt_overwrite;
    const char* password;
{
    uLong i;
    unz_global_info64 gi;
    int err;
    FILE* fout=NULL;

    err = unzGetGlobalInfo64(uf,&gi);//获取解压信息 unz_global_info64
    if (err!=UNZ_OK)
        printf("error %d with zipfile in unzGetGlobalInfo 
",err);

    for (i=0;i<gi.number_entry;i++)
    {
        if (do_extract_currentfile(uf,&opt_extract_without_path,
                                      &opt_overwrite,
                                      password) != UNZ_OK)//对当前内部文件解压
            break;

        if ((i+1)<gi.number_entry)
        {
            err = unzGoToNextFile(uf);//跳到下一个内部文件
            if (err!=UNZ_OK)
            {
                printf("error %d with zipfile in unzGoToNextFile
",err);
                break;
            }
        }
    }

    return 0;
}

int do_extract_onefile(uf,filename,opt_extract_without_path,opt_overwrite,password)
    unzFile uf;
    const char* filename;
    int opt_extract_without_path;
    int opt_overwrite;
    const char* password;
{
    int err = UNZ_OK;
    if (unzLocateFile(uf,filename,CASESENSITIVITY)!=UNZ_OK)
    {
        printf("file %s not found in the zipfile
",filename);
        return 2;
    }

    if (do_extract_currentfile(uf,&opt_extract_without_path,
                                      &opt_overwrite,
                                      password) == UNZ_OK)
        return 0;
    else
        return 1;
}
/**
"Usage : miniunz [-e] [-x] [-v] [-l] [-o] [-p password] file.zip [file_to_extr.] [-d extractdir]

" 
           "  -e  Extract without pathname (junk paths)
" 
           "  -x  Extract with pathname
" 
           "  -v  list files
" 
           "  -l  list files
" 
           "  -d  directory to extract into
" 
           "  -o  overwrite files without prompting
" 
           "  -p  extract crypted file using password

"
           ***/
int main(argc,argv)
    int argc;
    char *argv[];
{
    const char *zipfilename=NULL;
    const char *filename_to_extract=NULL;
    const char *password=NULL;
    char filename_try[MAXFILENAME+16] = "";
    int i;
    int ret_value=0;
    int opt_do_list=0;
    int opt_do_extract=1;
    int opt_do_extract_withoutpath=0;
    int opt_overwrite=0;
    int opt_extractdir=0;
    const char *dirname=NULL;
    unzFile uf=NULL;

    do_banner();
    if (argc==1)
    {
        do_help();//提示帮助
        return 0;
    }
    else
    {
        for (i=1;i<argc;i++)
        {
            if ((*argv[i])=='-')
            {
                const char *p=argv[i]+1;

                while ((*p)!='')
                {
                    char c=*(p++);;
                    if ((c=='l') || (c=='L'))
                        opt_do_list = 1;
                    if ((c=='v') || (c=='V'))
                        opt_do_list = 1;
                    if ((c=='x') || (c=='X'))
                        opt_do_extract = 1;
                    if ((c=='e') || (c=='E'))
                        opt_do_extract = opt_do_extract_withoutpath = 1;
                    if ((c=='o') || (c=='O'))
                        opt_overwrite=1;
                    if ((c=='d') || (c=='D'))
                    {
                        opt_extractdir=1;
                        dirname=argv[i+1];//解压到dirname目录路径
                    }

                    if (((c=='p') || (c=='P')) && (i+1<argc))
                    {
                        password=argv[i+1];//密码为password
                        i++;
                    }
                }
            }
            else
            {
                if (zipfilename == NULL)
                    zipfilename = argv[i];//zip的文件名zipfilename
                else if ((filename_to_extract==NULL) && (!opt_extractdir))
                        filename_to_extract = argv[i] ;//如果没有指定解压路径dirname，zip文件解压为指定的名称filename_to_extract
            }
        }
    }

    if (zipfilename!=NULL)
    {

#        ifdef USEWIN32IOAPI
        zlib_filefunc64_def ffunc;
#        endif

        strncpy(filename_try, zipfilename,MAXFILENAME-1);//拷贝filename_try，防止越界
        /* strncpy doesnt append the trailing NULL, of the string is too long. */
        filename_try[ MAXFILENAME ] = '';

#        ifdef USEWIN32IOAPI
        fill_win32_filefunc64A(&ffunc);
        uf = unzOpen2_64(zipfilename,&ffunc);
#        else
        uf = unzOpen64(zipfilename);//打开zip文件
#        endif
        if (uf==NULL)
        {
            strcat(filename_try,".zip");//如果没有成功，尝试添加后缀名.zip
#            ifdef USEWIN32IOAPI
            uf = unzOpen2_64(filename_try,&ffunc);
#            else
            uf = unzOpen64(filename_try);
#            endif
        }
    }

    if (uf==NULL)
    {
        printf("Cannot open %s or %s.zip
",zipfilename,zipfilename);
        return 1;
    }
    printf("%s opened
",filename_try);

    if (opt_do_list==1)
        ret_value = do_list(uf);//查看里面的zip文件里面的目录结果
    else if (opt_do_extract==1)
    {
#ifdef _WIN32
        if (opt_extractdir && _chdir(dirname))//如果指定了解压路径
#else
        if (opt_extractdir && chdir(dirname))//修改当前工作目录
#endif
        {
          printf("Error changing into %s, aborting
", dirname);
          exit(-1);
        }

        if (filename_to_extract == NULL)
            ret_value = do_extract(uf, opt_do_extract_withoutpath, opt_overwrite, password);
        else
            ret_value = do_extract_onefile(uf, filename_to_extract, opt_do_extract_withoutpath, opt_overwrite, password);//指定解压名称
    }

    unzClose(uf);

    return ret_value;
}

我自己的封装

ZipTool.h

#pragma once
#include <direct.h>
#include "unzip.h"

#define WRITEBUFFERSIZE 8192

#if (!defined(_WIN32)) && (!defined(WIN32)) && (!defined(__APPLE__))
#ifndef __USE_FILE_OFFSET64
#define __USE_FILE_OFFSET64
#endif
#ifndef __USE_LARGEFILE64
#define __USE_LARGEFILE64
#endif
#ifndef _LARGEFILE64_SOURCE
#define _LARGEFILE64_SOURCE
#endif
#ifndef _FILE_OFFSET_BIT
#define _FILE_OFFSET_BIT 64
#endif
#endif

#ifdef __APPLE__
// In darwin and perhaps other BSD variants off_t is a 64 bit value, hence no need for specific 64 bit functions
#define FOPEN_FUNC(filename, mode) fopen(filename, mode)
#define FTELLO_FUNC(stream) ftello(stream)
#define FSEEKO_FUNC(stream, offset, origin) fseeko(stream, offset, origin)
#else
//#define FOPEN_FUNC(filename, mode) fopen64(filename, mode)
//#define FTELLO_FUNC(stream) ftello64(stream)
//#define FSEEKO_FUNC(stream, offset, origin) fseeko64(stream, offset, origin)

#define FOPEN_FUNC(filename, mode) fopen(filename, mode)
#define FTELLO_FUNC(stream) ftello(stream)
#define FSEEKO_FUNC(stream, offset, origin) fseeko(stream, offset, origin)
#endif

class ZipTool
{
public:
    ZipTool();
    ~ZipTool();
    int UnZip(char* zipdir,char* password);//默认的目录解压
    int UnZip(char* zipdir, char* password,char* toUnZipdir);//指定的目录解压
    int Zip();
private:
    unzFile uf = NULL;
    int do_extract(unzFile uf, int opt_extract_without_path, int opt_overwrite, const char * password);
    int do_extract_currentfile(unzFile uf, const int * popt_extract_without_path, int * popt_overwrite, const char * password);
    void change_file_date(const char * filename, uLong dosdate, tm_unz tmu_date);
    int mymkdir(const char * dirname);
    int makedir(char * newdir);
    char* UnZipdir;
};

ZipTool.cpp

#include "stdafx.h"
#include "ZipTool.h"
ZipTool::ZipTool()
{
    UnZipdir = NULL;
}


ZipTool::~ZipTool()
{
}

int ZipTool::UnZip(char * zipdir, char * password){
    UnZipdir = NULL;
    if (zipdir != NULL){
        uf = unzOpen64(zipdir);//打开zip文件
    }
    if (uf == NULL){
        return 1;
    }
    int ret_value = do_extract(uf, 0, 1, password);
    unzClose(uf);
    return ret_value;
}
/**
toUnZipdir:加 //或
**/
int ZipTool::UnZip(char * zipdir, char * password, char * toUnZipdir)
{
    if (toUnZipdir!=NULL&&!PathFileExists(CString(toUnZipdir))) {
        //int pos=strlen(toUnZipdir);
        //if((toUnZipdir[pos-1]!= '/')&&(toUnZipdir[pos - 1]!= '\'))
        //    toUnZipdir
        makedir(toUnZipdir);
    }
    if (zipdir != NULL) {
        uf = unzOpen64(zipdir);//打开zip文件
    }
    if (uf == NULL) {
        return 1;
    }
    UnZipdir = toUnZipdir;
    int ret_value = do_extract(uf, 0, 1, password);
    unzClose(uf);
    UnZipdir = NULL;
    return ret_value;
}


/**
打开一个ZIP文件后，
需要先使用unzGetGlobalInfo64来取得该文件的一些信息，来了解这个压缩包里一共包含了多少个文件，等等。
目前我们用得着的就是这个文件数目。
然后开始遍历ZIP中的文件，初始时自动会定位在第一个文件，以后处理完一个后用unzGoToNextFile来跳到下一个文件。

对于每个内部文件，可用unzGetCurrentFileInfo64来查内部文件名。

这个文件名和刚才zipOpenNewFileInZip的第二个参数是一样的形式，所以有可能包含路径。
也有可能会以路径分隔符（/）结尾，表明这是个目录项（其实压缩操作的时候也可以针对目录写入这样的内部文件，上面没有做）。
所以接下来要根据情况创建（多级）目录。
unzGetCurrentFileInfo64的第三个参数是unz_file_info64结构，其中也有一项包含了dosDate信息，可以还原文件时间。

对于非目录的内部文件，用 unzOpenCurrentFile，打开，然后unzReadCurrentFile读取文件内容，写入到真实文件中。
unzReadCurrentFile返回 0 表示文件读取结束。


uf ：zip文件对象
opt_extract_without_path ：0:解压出来包含中间路径 1：解压出来不包含中间路径
opt_overwrite ：0 ：不覆盖 1：覆盖
password ：密码

**/
int ZipTool::do_extract(unzFile uf,int opt_extract_without_path,int opt_overwrite,const char* password)
{
    uLong i;
    unz_global_info64 gi;
    int err;
    FILE* fout = NULL;

    err = unzGetGlobalInfo64(uf, &gi);//获取解压信息 unz_global_info64
    if (err != UNZ_OK)
        printf("error %d with zipfile in unzGetGlobalInfo 
", err);

    for (i = 0; i<gi.number_entry; i++)
    {
        if (do_extract_currentfile(uf, &opt_extract_without_path,
            &opt_overwrite,
            password) != UNZ_OK)//对当前内部文件解压
            break;

        if ((i + 1)<gi.number_entry)
        {
            err = unzGoToNextFile(uf);//跳到下一个内部文件
            if (err != UNZ_OK)
            {
                printf("error %d with zipfile in unzGoToNextFile
", err);
                break;
            }
        }
    }

    return 0;
}


/***
popt_extract_without_path : 解压的时候是否需要中间的路径
**/
int ZipTool::do_extract_currentfile(unzFile uf, const int* popt_extract_without_path, int* popt_overwrite, const char* password)
{
    char filename_inzip[256];
    char* filename_withoutpath;
    char* p;
    int err = UNZ_OK;
    FILE *fout = NULL;
    void* buf;
    uInt size_buf;

    unz_file_info64 file_info;
    uLong ratio = 0;
    err = unzGetCurrentFileInfo64(uf, &file_info, filename_inzip, sizeof(filename_inzip), NULL, 0, NULL, 0);//filename_inzip 得到uf内部的文件名

    if (err != UNZ_OK)
    {
        printf("error %d with zipfile in unzGetCurrentFileInfo
", err);
        return err;
    }

    if (UnZipdir) {
        char filename_tmpzip[256];
        sprintf(filename_tmpzip, "%s%s",UnZipdir, filename_inzip);
        //filename_inzip[0] = filename_tmpzip;
        strncpy(filename_inzip, filename_tmpzip, 256);
    }
    size_buf = WRITEBUFFERSIZE;
    buf = (void*)malloc(size_buf);
    if (buf == NULL)
    {
        printf("Error allocating memory
");
        return UNZ_INTERNALERROR;
    }

    p = filename_withoutpath = filename_inzip;
    while ((*p) != '')
    {
        if (((*p) == '/') || ((*p) == '\'))
            filename_withoutpath = p + 1;//得到最底层的文件名
        p++;
    }

    if ((*filename_withoutpath) == '')//如果底层文件名是一个目录，那么就创建目录
    {
        if ((*popt_extract_without_path) == 0)
        {
            printf("creating directory: %s
", filename_inzip);
            mymkdir(filename_inzip);
        }
    }
    else
    {
        const char* write_filename;
        int skip = 0;

        if ((*popt_extract_without_path) == 0)
            write_filename = filename_inzip;//包含中间路径
        else
            write_filename = filename_withoutpath;//不包含中间路径
        //if (password) {
            err = unzOpenCurrentFilePassword(uf, password);//打开当前内部文件
            if (err != UNZ_OK)
            {
                printf("error %d with zipfile in unzOpenCurrentFilePassword
", err);
            }
        //}
        if (((*popt_overwrite) == 0) && (err == UNZ_OK))//设置为重写，并且打开成功
        {
            char rep = 0;
            FILE* ftestexist;
            ftestexist = FOPEN_FUNC(write_filename, "rb");
            if (ftestexist != NULL)//已经存在这个解压出的文件，会不停询问是否覆盖，直到得到确切答案
            {
                fclose(ftestexist);
                do
                {
                    char answer[128];
                    int ret;

                    printf("The file %s exists. Overwrite ? [y]es, [n]o, [A]ll: ", write_filename);
                    ret = scanf("%1s", answer);
                    if (ret != 1)
                    {
                        exit(EXIT_FAILURE);
                    }
                    rep = answer[0];
                    if ((rep >= 'a') && (rep <= 'z'))
                        rep -= 0x20;
                } while ((rep != 'Y') && (rep != 'N') && (rep != 'A'));
            }

            if (rep == 'N')
                skip = 1;

            if (rep == 'A')
                *popt_overwrite = 1;//设置popt_overwrite为全部覆盖
        }

        if ((skip == 0) && (err == UNZ_OK))//覆盖
        {
            fout = FOPEN_FUNC(write_filename, "wb");
            /* some zipfile don't contain directory alone before file */
            if ((fout == NULL) && ((*popt_extract_without_path) == 0) &&
                (filename_withoutpath != (char*)filename_inzip))
            {
                //FOPEN_FUNC(write_filename,"wb")本身是创建文件，可是如果没有现成的上级目录，创建不会成功，所以说明不存在对应的目录
                //filename_inzip,filename_withoutpath,write_filename是同一个字符串的不同位置，所以可以任意操作其中一个
                char c = *(filename_withoutpath - 1);
                *(filename_withoutpath - 1) = '';//修改了最后一个路径符为结束符，就是一个路径
                makedir((char*)write_filename);//创建路径
                *(filename_withoutpath - 1) = c;//还原原来的路径
                fout = FOPEN_FUNC(write_filename, "wb");
            }

            if (fout == NULL)
            {
                printf("error opening %s
", write_filename);
            }
        }

        if (fout != NULL)
        {
            printf(" extracting: %s
", write_filename);

            do
            {
                err = unzReadCurrentFile(uf, buf, size_buf);//8K的内存
                if (err<0)
                {
                    printf("error %d with zipfile in unzReadCurrentFile
", err);
                    break;
                }
                if (err>0)
                    if (fwrite(buf, err, 1, fout) != 1)
                    {
                        printf("error in writing extracted file
");
                        err = UNZ_ERRNO;
                        break;
                    }
            } while (err>0);
            if (fout)
                fclose(fout);

            if (err == 0)//结束
                change_file_date(write_filename, file_info.dosDate,
                    file_info.tmu_date);//还原创建时间
        }

        if (err == UNZ_OK)
        {
            err = unzCloseCurrentFile(uf);
            if (err != UNZ_OK)
            {
                printf("error %d with zipfile in unzCloseCurrentFile
", err);
            }
        }
        else
            unzCloseCurrentFile(uf); /* don't lose the error */
    }
    free(buf);
    return err;
}


/* change_file_date : change the date/time of a file
filename : the filename of the file where date/time must be modified
dosdate : the new date at the MSDos format (4 bytes)
tmu_date : the SAME new date at the tm_unz format */
void ZipTool::change_file_date(const char *filename,uLong dosdate,tm_unz tmu_date){
#ifdef _WIN32
    HANDLE hFile;
    FILETIME ftm, ftLocal, ftCreate, ftLastAcc, ftLastWrite;

    hFile = CreateFileA(filename, GENERIC_READ | GENERIC_WRITE,
        0, NULL, OPEN_EXISTING, 0, NULL);
    GetFileTime(hFile, &ftCreate, &ftLastAcc, &ftLastWrite);
    DosDateTimeToFileTime((WORD)(dosdate >> 16), (WORD)dosdate, &ftLocal);
    LocalFileTimeToFileTime(&ftLocal, &ftm);
    SetFileTime(hFile, &ftm, &ftLastAcc, &ftm);
    CloseHandle(hFile);
#else
#ifdef unix || __APPLE__
    struct utimbuf ut;
    struct tm newdate;
    newdate.tm_sec = tmu_date.tm_sec;
    newdate.tm_min = tmu_date.tm_min;
    newdate.tm_hour = tmu_date.tm_hour;
    newdate.tm_mday = tmu_date.tm_mday;
    newdate.tm_mon = tmu_date.tm_mon;
    if (tmu_date.tm_year > 1900)
        newdate.tm_year = tmu_date.tm_year - 1900;
    else
        newdate.tm_year = tmu_date.tm_year;
    newdate.tm_isdst = -1;

    ut.actime = ut.modtime = mktime(&newdate);
    utime(filename, &ut);
#endif
#endif
}

int ZipTool::mymkdir(const char* dirname){
    int ret = 0;
#ifdef _WIN32
    ret = _mkdir(dirname);
#elif unix
    ret = mkdir(dirname, 0775);
#elif __APPLE__
    ret = mkdir(dirname, 0775);
#endif
    return ret;
}

int ZipTool::makedir(char *newdir){
    char *buffer;
    char *p;
    int  len = (int)strlen(newdir);

    if (len <= 0)
        return 0;

    buffer = (char*)malloc(len + 1);
    if (buffer == NULL)
    {
        printf("Error allocating memory
");
        return UNZ_INTERNALERROR;
    }
    strcpy(buffer, newdir);

    if (buffer[len - 1] == '/') {
        buffer[len - 1] = '';
    }
    if (mymkdir(buffer) == 0)
    {
        free(buffer);
        return 1;
    }

    p = buffer + 1;
    while (1)
    {
        char hold;

        while (*p && *p != '\' && *p != '/')
            p++;
        hold = *p;
        *p = 0;
        if ((mymkdir(buffer) == -1) && (errno == ENOENT))
        {
            printf("couldn't create directory %s
", buffer);
            free(buffer);
            return 0;
        }
        if (hold == 0)
            break;
        *p++ = hold;
    }
    free(buffer);
    return 1;
}


int ZipTool::Zip()
{
    return 0;
}

 调用代码

ZipTool* zip = new ZipTool();

//zip->UnZip("C:\Users\ZhouXiaodong\Desktop\001星星.zip",NULL);

zip->UnZip("C:\Users\ZhouXiaodong\Desktop\001星星.zip",NULL,"./001星星/");

 注意，官方提供的库 zlibwapi.dll 是32位的，会出现异常，64位库需要自己编译

编译路径，zlib-1.2.11contribvstudio，里面有各个版本的源码

在密码解压的时候遇见

err = unzOpenCurrentFilePassword(uf, password);

报错

#define UNZ_PARAMERROR                  (-102)
#define UNZ_BADZIPFILE                  (-103)

https://blog.csdn.net/fyyyr/article/details/79252677