Question

currently I am struggeling with a little problem:
I want create FastCGI/CGI binding for the nekoVM. This is done by writing some clue C/C++ code that is loaded by the VM. I want to make the behaviour of my binding as compatible as possible with neko native API (mod_neko, mod_tora). With mod_neko it is possible to get all HTTP headers the client send.
As far as I know you can get HTTP headers with FastCGI only by calling getenv('header_name'). To use this function you need to know the name of all headers.

My question: Is there any possibility to get all headers the client send?

Answer 1

You can use the externally-defined, null-terminated environ variable on most systems to get an array of all environment variables, which you could iterate to grab the headers you need (assuming FastCGI sets up the environment variables in a sensible way):

#include <stdio.h>

int main(int argc, char *argv[])
{
    extern char **environ;
    for (int i = 0; environ[i] != NULL; i++)
    {
        printf("%s\n", environ[i]);
    }
}

See man 7 environ.