I do not understand: the exchange of data between C programs.

[valsorym]

Hello all. I can not understand, I'm sorry.
For example: If the web-server runs my program writed in C language (using CGI).
There written by:

...
 printf("Content-type: text/html\n\n\n");
 printf("Hello world!");
...

And the word "Hello world!" flies to the client that requested this CGI-script.
But I did draw the conclusion in the "stdin"!

As a web-server run my program, and intercepted a conclusion "stdin"?

I know how to exchange data between applications:
1. sockets. (But I did not create socket).
2. pipe (may, but is it my server runs the application as a way myProgram | webServer) It's hard!.

In a nutshell, you can explain?
I read about the CGI, FastCGI-much has been written, and then confused!

P.S. I want to create a small web-server which will run my program (written in C for example) and give result to the user.

Where dig it?

...
* I do not want to create a second Apache or lighttpd .. I just want to understand - how is it? x(
Forgive me if something is wrong.

 

[graudeejs]

Your server will execute your app and read it's output via pipe

 

[Alt]

CGI data coming to script with STDIN + ENV, server waits answer to STDOUT, STDERR will be written in errorlog. Some calls like popen can handle this.

 

[valsorym]

CGI data coming to script with STDIN + ENV, server waits answer to STDOUT, STDERR will be written in errorlog. Some calls like popen can handle this.

Your server will execute your app and read it's output via pipe

O, thank you. So "pipe" it is correct choose. popen is the thing, thanks.
"Now I know where to dig a tunnel!"