André Warnier wrote: "A cgi-bin program is a separate process from the Apache child that runs it." My tests (and the whole cgi logic in a web server) concluded that the cgi-script is a child of apache. This because the the ppid() of the cgi-script is the pid() of the apache server daemon. ;) Thanks for the tip, I haven?t thought on using an Apache Filter. But anyway, I think that the SIGPIPE signal has the same effect as an Apache Filter. I'm not sure, but I think Apache already has filters that send this kind of singnals to the cgi-script when the socket is closed. That's what SIGPIPE is all about. Apache routes the stdout from my cgi-script to the clients socket through a pipe, when the socket is closed, apache sends a SIGPIPE the my cgi-script telling that the client has disconnected. After all, I am not interested if the client has received 100% of the data. I am interested to know, how close to 100% did the client received. The cgi-script I'm writing, is a bit selfish. All he wants to know is yes or no, how much data did the client wasted on his request. If the data was not 100% received by the client because he cancelled, that's his problem, he can request again later. -----Original Message----- From: André Warnier [mailto:aw@xxxxxxxxxx] Sent: Saturday, March 21, 2009 1:03 PM To: users@xxxxxxxxxxxxxxxx Subject: Re: Re: CGI Child Process Question Lihet Ruben wrote: [...] I would look at this in another way. A cgi-bin program is a separate process from the Apache child that runs it. The Apache process starts the cgi-bin process, and arranges to read back everything that the cgi-bin writes to STDOUT. Then Apache sends this to the browser. In-between, there is buffering, so as someone pointed out, it is possible that after your cgi-bin has already finished its job of producing the output and has exited, Apache is still busy sending some chunks of output to the browser, and then the user cancels. In that case, your script would think that everything has been sent, while this is not the case. What I would thus do, is to implement your logic of verifying that the user has received everything, in an Apache output filter. It is still not perfect, but much "closer" to the browser. If the user interrupts the connection by hitting cancel, the filter would know, because it would get an i/o error when writing to the response socket. And it could notify your application. Now understand that if your client is behind a proxy that does buffering, then the proxy will still hold some data, while Apache is long done and the filter has told your application that everything was sent. And the user can still hit cancel then. So ultimately, to be 100% sure, the only solution is to ask the user, when he has finished downloading, to acknowledge receipt. I cannot think of an easy way to do that with a standard browser, but I can imagine a Java applet which gets the file from your server, writes it to a local file, and when it is done, makes a POST to the server to say it was done. --------------------------------------------------------------------- The official User-To-User support forum of the Apache HTTP Server Project. See <URL:http://httpd.apache.org/userslist.html> for more info. To unsubscribe, e-mail: users-unsubscribe@xxxxxxxxxxxxxxxx " from the digest: users-digest-unsubscribe@xxxxxxxxxxxxxxxx For additional commands, e-mail: users-help@xxxxxxxxxxxxxxxx --------------------------------------------------------------------- The official User-To-User support forum of the Apache HTTP Server Project. See <URL:http://httpd.apache.org/userslist.html> for more info. To unsubscribe, e-mail: users-unsubscribe@xxxxxxxxxxxxxxxx " from the digest: users-digest-unsubscribe@xxxxxxxxxxxxxxxx For additional commands, e-mail: users-help@xxxxxxxxxxxxxxxx
|