web(七)---fastcgi再进阶(请求和响应)官方例子

在fast-cgi源码的examples文件夹下有很多例子, 下面给出echo例子, 编译运行方法同上几节.

 

fast-cgi的API  google之.

http://fossies.org/dox/fcgi-2.4.0/fcgiapp_8h.html#a32f6950798054a70404ce24c22ea28b9

 

echo-cpp.cpp

#include <stdlib.h>

#ifdef _WIN32

#include <process.h>

#else

#include <unistd.h>

extern char ** environ;

#endif

#include "fcgio.h"

#include "fcgi_config.h"  // HAVE_IOSTREAM_WITHASSIGN_STREAMBUF



using namespace std;



// Maximum number of bytes allowed to be read from stdin

static const unsigned long STDIN_MAX = 1000000;



static void penv(const char * const * envp)

{

    cout << "<PRE>\n";

    for ( ; *envp; ++envp)

    {

        cout << *envp << "\n";

    }

    cout << "</PRE>\n";

}



static long gstdin(FCGX_Request * request, char ** content)

{

    char * clenstr = FCGX_GetParam("CONTENT_LENGTH", request->envp);

    unsigned long clen = STDIN_MAX;



    if (clenstr)

    {

        clen = strtol(clenstr, &clenstr, 10);

        if (*clenstr)

        {

            cerr << "can't parse \"CONTENT_LENGTH="

                 << FCGX_GetParam("CONTENT_LENGTH", request->envp)

                 << "\"\n";

            clen = STDIN_MAX;

        }



        // *always* put a cap on the amount of data that will be read

        if (clen > STDIN_MAX) clen = STDIN_MAX;



        *content = new char[clen];



        cin.read(*content, clen);

        clen = cin.gcount();

    }

    else

    {

        // *never* read stdin when CONTENT_LENGTH is missing or unparsable

        *content = 0;

        clen = 0;

    }



    // Chew up any remaining stdin - this shouldn't be necessary

    // but is because mod_fastcgi doesn't handle it correctly.



    // ignore() doesn't set the eof bit in some versions of glibc++

    // so use gcount() instead of eof()...

    do cin.ignore(1024); while (cin.gcount() == 1024);



    return clen;

}



int main (void)

{

    int count = 0;

    long pid = getpid();



    streambuf * cin_streambuf  = cin.rdbuf();

    streambuf * cout_streambuf = cout.rdbuf();

    streambuf * cerr_streambuf = cerr.rdbuf();



    FCGX_Request request;



    FCGX_Init();

    FCGX_InitRequest(&request, 0, 0);



    while (FCGX_Accept_r(&request) == 0)

    {

        // Note that the default bufsize (0) will cause the use of iostream

        // methods that require positioning (such as peek(), seek(),

        // unget() and putback()) to fail (in favour of more efficient IO).

        fcgi_streambuf cin_fcgi_streambuf(request.in);

        fcgi_streambuf cout_fcgi_streambuf(request.out);

        fcgi_streambuf cerr_fcgi_streambuf(request.err);



#if HAVE_IOSTREAM_WITHASSIGN_STREAMBUF

        cin  = &cin_fcgi_streambuf;

        cout = &cout_fcgi_streambuf;

        cerr = &cerr_fcgi_streambuf;

#else

        cin.rdbuf(&cin_fcgi_streambuf);

        cout.rdbuf(&cout_fcgi_streambuf);

        cerr.rdbuf(&cerr_fcgi_streambuf);

#endif



        // Although FastCGI supports writing before reading,

        // many http clients (browsers) don't support it (so

        // the connection deadlocks until a timeout expires!).

        char * content;

        unsigned long clen = gstdin(&request, &content);



        cout << "Content-type: text/html\r\n"

                "\r\n"

                "<TITLE>echo-cpp</TITLE>\n"

                "<H1>echo-cpp</H1>\n"

                "<H4>PID: " << pid << "</H4>\n"

                "<H4>Request Number: " << ++count << "</H4>\n";



        cout << "<H4>Request Environment</H4>\n";

        penv(request.envp);



        cout << "<H4>Process/Initial Environment</H4>\n";

        penv(environ);



        cout << "<H4>Standard Input - " << clen;

        if (clen == STDIN_MAX) cout << " (STDIN_MAX)";

        cout << " bytes</H4>\n";

        if (clen) cout.write(content, clen);



        if (content) delete []content;



        // If the output streambufs had non-zero bufsizes and

        // were constructed outside of the accept loop (i.e.

        // their destructor won't be called here), they would

        // have to be flushed here.

    }



#if HAVE_IOSTREAM_WITHASSIGN_STREAMBUF

    cin  = cin_streambuf;

    cout = cout_streambuf;

    cerr = cerr_streambuf;

#else

    cin.rdbuf(cin_streambuf);

    cout.rdbuf(cout_streambuf);

    cerr.rdbuf(cerr_streambuf);

#endif



    return 0;

}