管道通信实例

A程序作为服务器，不断从B程序接收数据，并发送到C程序中：
#include <stdio.h>
#include <conio.h>  
#include <tchar.h>
#include <Windows.h>
#include <process.h>
#include <stdlib.h>
const char *pStrPipeNameGet = "\\\\.\\pipe\\Name_pipe_demon_get";
const char *pStrPipeNameSend = "\\\\.\\pipe\\Name_pipe_demon_send";
const int BUFFER_MAX_LEN = 1024;
char buf[BUFFER_MAX_LEN];
DWORD dwLen;
HANDLE get, mSend, mutex;
LPCRITICAL_SECTION cs;
WCHAR* toWChar(const char *c)
{
    WCHAR wszClassName[256];
    memset(wszClassName, 0, sizeof(wszClassName));
    MultiByteToWideChar(CP_ACP, 0, c, strlen(c) + 1, wszClassName,\
    sizeof(wszClassName) / sizeof(wszClassName[0]));
    return wszClassName;
}
void beginGetThread(PVOID p)
{
    printf("服务器Get\n");
    printf("等待连接......\n");
    HANDLE hPipe = CreateNamedPipe(toWChar(pStrPipeNameGet),\
    PIPE_ACCESS_DUPLEX,PIPE_TYPE_MESSAGE | PIPE_READMODE_MESSAGE | PIPE_WAIT,\
    PIPE_UNLIMITED_INSTANCES, 0, 0, NMPWAIT_WAIT_FOREVER, 0);
    if (ConnectNamedPipe(hPipe, NULL) != NULL)//等待连接。  
    {
        printf("连接成功，开始接收数据\n");
        while (true)
        {
            WaitForSingleObject(mutex, INFINITE);
            EnterCriticalSection(cs);//接收客户端发送的数据  
            ReadFile(hPipe, buf, BUFFER_MAX_LEN, &dwLen, NULL);
            printf("接收到来自A的数据长度为%d字节\n", dwLen);
            printf("具体数据内容如下：");
            int bufSize;
            for (bufSize = 0; bufSize < (int)dwLen; bufSize++)
            {
                putchar(buf[bufSize]);
            }
            LeaveCriticalSection(cs);
            Sleep(500);
            ReleaseSemaphore(mutex, 1, NULL);
            putchar('\n');
        }
    }
    else
    {
        printf("连接失败\n");
    }
    DisconnectNamedPipe(hPipe);
    CloseHandle(hPipe);//关闭管道
}
void beginSendThread(PVOID p)
{
    printf("服务器Send\n");
    printf("等待连接......\n");
    HANDLE hPipe = CreateNamedPipe(toWChar(pStrPipeNameSend),PIPE_ACCESS_DUPLEX,\
    PIPE_TYPE_MESSAGE | PIPE_READMODE_MESSAGE | PIPE_WAIT,\
    PIPE_UNLIMITED_INSTANCES, 0, 0, NMPWAIT_WAIT_FOREVER, 0);
    if (ConnectNamedPipe(hPipe, NULL) != NULL)//等待连接。
    {
        printf("连接成功，开始发送缓冲区数据至B\n");
        while (true)  
        {
            WaitForSingleObject(mutex, INFINITE);
            EnterCriticalSection(cs);
            WriteFile(hPipe, buf, (int)dwLen, &dwLen, NULL);
            LeaveCriticalSection(cs);Sleep(500);
            ReleaseSemaphore(mutex, 1, NULL);
        }
    }
    else
    {
        printf("连接失败\n");
    }
    DisconnectNamedPipe(hPipe);
    CloseHandle(hPipe);//关闭管道
}
int _tmain(int argc, _TCHAR* argv[])
{
    cs = (LPCRITICAL_SECTION)malloc(sizeof(LPCRITICAL_SECTION));
    InitializeCriticalSection(cs);
    mutex = CreateSemaphore(NULL, 1, 1, TEXT("mutex"));
    _beginthread(beginGetThread, NULL, NULL);
    _beginthread(beginSendThread, NULL, NULL);
    Sleep(INFINITE);DeleteCriticalSection(cs);
    return 0;
}

B程序不断接收从键盘输入的数据，数据以回车结束，并发送给A
#include <stdio.h>
#include <tchar.h>
#include <Windows.h>
#include <conio.h>
const char *pStrPipeName = "\\\\.\\pipe\\Name_pipe_demon_get";
const int BUFFER_MAX_LEN = 1024;
char buf[BUFFER_MAX_LEN];
int _tmain(int argc, _TCHAR* argv[])
{
    printf("按任意键以开始连接Get\n");
    _getch();
    printf("A开始等待......\n");
    if (!WaitNamedPipe(pStrPipeName, NMPWAIT_WAIT_FOREVER))
    {
        printf("Error! 连接Get失败\n");
        return 0;
    }
    HANDLE hPipe = CreateFile(pStrPipeName, GENERIC_WRITE, 0,NULL,  
    OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
    while (true)
    {
        printf("请输入要向服务端发送的数据，回车键结束，最大1024个字节\n");
        DWORD dwLen = 0;
        int bufSize;
        for (bufSize = 0; bufSize < BUFFER_MAX_LEN; bufSize++)
        {
            buf[bufSize] = getchar();
            if (buf[bufSize] == '\n') break;
        }//向服务端发送数据  
        if (WriteFile(hPipe, buf, bufSize, &dwLen, NULL))
        {
             printf("数据写入完毕共%d字节\n", dwLen);
        }
        else
        {
            printf("数据写入失败\n");
        }
        Sleep(1000);
    }
    CloseHandle(hPipe);
    return 0;
}

C程序接收到从A发送来的数据，并转换成大写写入文件
#include <stdio.h>
#include <tchar.h>
#include <Windows.h>
#include <conio.h>
const char *pStrPipeName = "\\\\.\\pipe\\Name_pipe_demon_send";
const int BUFFER_MAX_LEN = 1024;
char buf[BUFFER_MAX_LEN];
DWORD dwLen = 0;
int _tmain(int argc, _TCHAR* argv[])
{
    printf("按任意键以开始连接Send\n");
    _getch();
    printf("B开始等待......\n");
    if (!WaitNamedPipe(pStrPipeName, NMPWAIT_WAIT_FOREVER))
    {
        printf("Error! 连接Send失败\n");
        return 0;
    }
   HANDLE hPipe = CreateFile(pStrPipeName, GENERIC_READ, 0,NULL,
   OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
    while (true)
    {// 接收服务端发回的数据
        ReadFile(hPipe, buf, BUFFER_MAX_LEN, &dwLen, NULL);//读取管道中的内容（管道是一种特殊的文件）
        printf("接收服务端发来的信息,长度为%d字节\n", dwLen);
        printf("具体数据内容如下：");
        HANDLE hWrite = CreateFile(_T("data.txt"), GENERIC_READ | GENERIC_WRITE,
        FILE_SHARE_READ, NULL, OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
        for (int j = 0; j <= (int )dwLen; j++)
        {
            putchar(buf[j]);
            buf[j] = toupper(buf[j]);
       }
       putchar('\n');
       SetFilePointer(hWrite, NULL, NULL, FILE_END);
       WriteFile(hWrite, buf, (int)dwLen, NULL, NULL);
       WriteFile(hWrite, "\n", 1, NULL, NULL);
       CloseHandle(hWrite);
       Sleep(1000);
    }
    CloseHandle(hPipe);
    return 0;
}