a_tcpecho_svr.cpp

一个不错

/* Copyright is licensed under GNU LGPL.                 by I.J.Wang 2006

 TCP server for echo service

 Build: make a_tcpecho_svr
*/
#include "../src/wysockfile.h"
#include "../src/wysockaddrinet4.h"
#include "../src/wy_uty.h"
#include <sys/types.h>
#include <sys/resource.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <signal.h>
#include <unistd.h>

// SIGCHLD handler: wait until a child has exited.
//
static void sig_handle(int sig_num)
{
 int status;
 while(::wait3(&status, WNOHANG, NULL)) {};
};

static WyRet echo_service_for(WySockFile& cli_sock, const WySockAddrINet4& cli_addr)
try {
 WyStr rbuf;
 rbuf._reserve(1024);

 // loop until eof: read data from cli_sock into rbuf and write back to cli_sock
 for(;;) {
   try {
     cli_sock >> rbuf;
     if(rbuf.size()==0) {
       return(Ok);      // eof
     }
     cli_sock << rbuf;
   }
   catch(const WyByteFlow::Reply& e) {
     if(e==Wym_EINTR) {
       continue;
     }
     WY_THROW( WyRet(e) );
   }
 }
 return(Ok);
}
catch(const WyRet& e) {
 Wy::cerr << Wy::wrd(e) << '\n';
 WY_TERMINATE("WyRet error");
}
catch(...) {
 WY_TERMINATE("unknown throw type");
};

static const char* syntax=
 "[Syntax]$./a_tcpecho_svr port\n";

int main(int argc, char* argv[])
try {
 if(argc!=2) {
   Wy::cout << syntax;
   return(-1);
 }
 WyRet r;
 uint16_t port;

 // convert argv[1] to uint16_t and save into port
 if((r=Wy::_strnum(port,NULL,argv[1]))!=Ok) {
   WY_THROW(r);
 }

 ::signal(SIGCHLD,sig_handle);

 // setup svr_msock as the master socket
 WySockFile svr_msock(PF_INET,SOCK_STREAM,0);
 const WySockAddrINet4 SvrAddr(INADDR_ANY,port);

 if((r=svr_msock.bind(SvrAddr))!=Ok) {
   WY_THROW(r);
 }
 if((r=svr_msock.listen(0))!=Ok) {
   WY_THROW(r);
 }

 // endless loop
 for(;;) {
   WySockFile a_sock;
   WySockAddrINet4 a_addr;

   // accept an incoming socket and for a child process for it
   if((r=svr_msock.accept(a_sock,a_addr))!=Ok) {
     WY_THROW(r);
   }
   const ::pid_t cpid( ::fork() );
   if(cpid==-1) {
     WY_THROW( WyRet(errno) );
   }
   if(cpid==0) {
     continue;
   }

   // Child process
   //
   svr_msock.reset();   // reset unused socket
   if((r=echo_service_for(a_sock,a_addr))!=Ok) {
     Wy::cerr << "Child process error: " << Wy::wrd(r) << '\n';
     return(r->c_repcode());
   }
   return(0);
 }
 // UNREACHABLE
 return(0);
}
catch(const WyRet& e) {
 if(e!=Ok) {
   Wy::cerr << Wy::wrd(e) << '\n';
 }
 return e->c_repcode();
}
catch(...) {
 Wy::cerr << "main caught(...)\n";
 return(-1);
};