用C庫函數寫的拷貝檔案的例子

下面這段代碼，是用C的標準庫檔案編寫的拷貝檔案的例子程式。可移植性較強，稍加修改就可以在Windows平台下的任何C/C++編譯器下正常運行。

global.cpp----------------------------------------------------------------
#include "global.h"
#include "stdio.h"
#include "windows.h"

void DoEvents()
{
 MSG msg;
 while(PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))
 {
  TranslateMessage(&msg);
  DispatchMessage(&msg);
 }
}

//參數表：目標檔案、源檔案、百分比(可在對話方塊類的Timer訊息的處理函數中更新進度條)
bool copyfile(char * dst,char *src,long &perc)
{
    const long BUF_SIZE = 40960;
    unsigned long filelen=0;
    unsigned char buf[BUF_SIZE];
    long i,j,k;

    perc =0;

    FILE * fpd= fopen(dst,"wb");
    FILE * fps= fopen(src,"rb");

    if (NULL==fpd || NULL==fps)
    {
        if (NULL!=fpd)fclose(fpd);
        if (NULL!=fps)fclose(fps);
        return false;
    }

    fseek(fps,   0,   SEEK_END);
    filelen=ftell(fps);

    fseek(fps,0,SEEK_SET);

    j = filelen / BUF_SIZE;
    k = filelen % BUF_SIZE;

    for (i =0 ; i< j ; i++)
    {
        fread(buf,BUF_SIZE,1,fps);
        fwrite(buf,BUF_SIZE,1,fpd);
        if (0==(i & 0xf)){perc =100 * i / j ; DoEvents();}
    }

    fread(buf,k,1,fps);
    fwrite(buf,k,1,fpd);

    perc=100;

    fclose(fps);
    fclose(fpd);
    return true;
}

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