D语言下文件过滤copy的三种方式比较

来源：互联网发布：比特彗星监听端口堵塞编辑：程序博客网时间：2024/05/23 14:19

module cpAmrs;import std.stdio;import std.file;import std.exception;import std.path:isValidPath,baseName;import std.datetime;import std.string;import std.algorithm.searching;extern(C) int setlocale(int, char*);static this(){    import core.stdc.wchar_;    fwide(core.stdc.stdio.stdout, 1);    setlocale(0, cast(char*)"china");}void main(string[] args){  writeln(" args[0] "~ args[0]);    if(args.length <=1)    {        writeln("请输入　要查找的目录　要查找的文件扩展名　　copy的目地目录");        writeln("程序自动退出!");        return;    }    writeln("准备对比!");    writeln(" start 0*************************************************************** ");    StopWatch sw;    sw.start();    cpFiles(args[1],args[2],args[3]);    sw.stop();    writeln(" cpFiles use time is ",sw.peek().msecs," msec");    writeln(" start 1*************************************************************** ");    sw.reset();    sw.start();    cpFiles1(args[1],args[2],args[3]);    sw.stop();    writeln(" cpFiles1 use time is ",sw.peek().msecs," msec");    writeln(" start 2*************************************************************** ");    sw.reset();    sw.start();    cpFiles2(args[1],args[2],args[3]);    sw.stop();    writeln(" cpFiles2 use time is ",sw.peek().msecs," msec");   }void cpFiles(string strDir,string strExt,string cpTo){ import std.algorithm.iteration; import std.algorithm.searching;    if(!isValidPath(strDir))     {        writeln(strDir ~ "is not Valid Path.");        return;    }    auto fFiles = dirEntries(strDir, SpanMode.depth).filter!(f => f.name.endsWith("."~strExt));     //if(!exists(cpTo~"\0"))     foreach(f; fFiles)    {        cpFile(f,cpTo~"0\\");    }}void cpFile(DirEntry f,string cpTo){     auto a = SysTime(DateTime.fromISOExtString("2016-03-04T20:00:00"));    auto b = SysTime(DateTime.fromISOExtString("2016-03-04T22:30:00"));    if(f.timeLastModified.opCmp(a) >= 0 && f.timeLastModified.opCmp(b) <= 0)    {        writeln("Will Copy file ",f.name);        f.copy(cpTo ~ baseName(f.name));        //string strcopy = "copy " ~ f.name ~ " " ~ "F:\\HJTZY2";        //import std.process;         //enforce(spawnShell(strcopy.dup()),"copyFile() error");    }}void cpFiles1(string strDir,string strExt,string cpTo){    if(!isValidPath(strDir))     {        writeln(strDir ~ "is not Valid Path.");        return;    }    auto dFiles = dirEntries(strDir,"{"~strExt~"}", SpanMode.depth);//.filter!(f => f.name.endsWith("."~strExt))     writeln(strDir);    foreach(f; dFiles)    {        cpFile(f,cpTo);    }}void cpFiles2(string strDir,string strExt,string cpTo){     foreach(f;dirEntries(strDir, SpanMode.depth))    {        if(!f.name.endsWith("."~strExt)) continue;        try        {             cpFile(f,cpTo~"2\\");        }        catch(Exception e)        {            writeln("file name is "~f.name," catch %s", e.msg);        }    }}

编译并测试

dmd cpAmrs -releasepausecpAmrs F:\HJTZY\1a amr f:\weixin_test\

比较结果：在运行了一次后，第３个稳定而且快，第２个只适合当前目录，第１种第一次运行时稍长些，以后可能会比第３个稍少，总体来说，第３个稳定。

原创，转发请标注来自　未来之眼　谢谢。

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