c++ pipe实现父子进程通信
程序员文章站
2023-08-30 09:32:33
1、父子进程通信pipe编程流程 -创建管道 -设置进程的输出到管道 -创建进程 -关闭管道写句柄 -读管道读句柄,把数据读到一个buffer里 2、注意事项 -读管道数据的时候,一定要关闭写句柄; -父子进程通信时,句柄的传递多通过继承来完成,父进程允许这些句柄为子进程继承;创建子进程,是否继承的 ......
1、父子进程通信pipe编程流程
-创建管道
-设置进程的输出到管道
-创建进程
-关闭管道写句柄
-读管道读句柄,把数据读到一个buffer里
2、注意事项
-读管道数据的时候,一定要关闭写句柄;
-父子进程通信时,句柄的传递多通过继承来完成,父进程允许这些句柄为子进程继承;创建子进程,是否继承的属性要设置为true;
// pdfprintconsole.cpp : 此文件包含 "main" 函数。程序执行将在此处开始并结束。 // #include "pch.h" #include <iostream> #include <windows.h> #include<tchar.h> #include <string.h> int main() { int page_index = 0; char currentbuff[1000] = { 0 }; char cachfilename[1000] = { 0 }; char printcommand[1000] = { 0 }; char command[500] = { 0 }; handle handle = 0; bool btest = 0; security_attributes sa = { 0 }; dword dwnumberofbytesread = 0; char szbuffer[10000] = { 0 }; dword ret = 0; handle hpipeoutputread = null; handle hpipeoutputwrite = null; startupinfoa si = { 0 }; process_information pi = { 0 }; sa.binherithandle = true; // true为管道可以被子进程所继承 sa.lpsecuritydescriptor = null; // 默认为null sa.nlength = sizeof(security_attributes); // create pipe for standard output redirection. createpipe(&hpipeoutputread, // read handle &hpipeoutputwrite, // write handle &sa, // security attributes 0 // number of bytes reserved for pipe - 0 default ); // make child process use hpipeoutputwrite as standard out, // and make sure it does not show on screen. si.cb = sizeof(si); si.dwflags = startf_useshowwindow | startf_usestdhandles; si.wshowwindow = sw_hide; //si.hstdinput = hpipeinputread; si.hstdoutput = hpipeoutputwrite; si.hstderror = hpipeoutputwrite; //strcpy_s(command, " -printer \"fx docucentre s2011\" -paper 9 -printermargins c:\\users\\qj\\desktop\\f3044688ce88a4b0a78c16ba85076570-5378-0010-0.png"); strcpy_s(command," -printer \"fx docucentre s2011\" -listpapers"); //一共执行三次 for (int i = 0; i < 3; i++) { if (!createprocessa("c:\\users\\qj\\source\\repos\\windowsformsapp1\\x64\\debug\\pdfprint.exe", command, null, null, true, null, null, null, &si, &pi)) { //afxmessagebox("缺失pdfprint.exe文件",0,0); break; } else { handle hprocess = pi.hprocess; //等待进程退出 //closehandle(hpipeoutputread); while (waitforsingleobject(hprocess, infinite) != wait_object_0); getexitcodeprocess(hprocess, &ret); //如果ret!=0,异常退出; // closehandle(hpipeoutputwrite); while (true) { btest = readfile( hpipeoutputread, // handle of the read end of our pipe &szbuffer, // address of buffer that receives data sizeof(szbuffer), // number of bytes to read &dwnumberofbytesread, // address of number of bytes read null // non-overlapped. ); if (!btest) { break; } // do something with data. szbuffer[dwnumberofbytesread] = 0; // null terminate } if (!ret) { printf("123%s456\nbtest:%d\n", szbuffer, btest); closehandle(hprocess); closehandle(hpipeoutputread); break; } } } //std::cout << "hello world!\n"; system("pause"); }
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