my server pset throws up "505 HTTP Version Not Supported" but i think it should not

Question

Am done with pset6 but want to test if I implemented the server correctly but when I type in the URL (e.g: 192.#.#.#:port#/cat.jpg) into the browser as specified by David, I get the following error "505 HTTP Version Not Supported" which i think the server should not throw that error considering the fact that the http version is HTTP/1.1

I have tried all sorts and still cannot figure out where the issue is. Also tried running gdb but it appears it is not useable here.

see below my code where I think the issue may lie. Looking through the code the content of check_request[2] should be "HTTP/1.1" . Please help me out

Edit: removed most code

Relevant code:

//Check if the http version is "HTTP/1.1" if(strcasecmp(check_request[2], "HTTP/1.1") != 0) { printf("505 HTTP Version Not Supported\n"); continue;
}

Answer 1

First, recall what the spec says about the request-line:

Per 3.1.1 of https://www.rfc-editor.org/rfc/rfc7230, a request-line is defined as

method SP request-target SP HTTP-version CRLF 

wherein SP represents a single space ( ) and CRLF represents \r\n. None of

method, request-target, and HTTP-version, meanwhile, may contain SP.

If you put some debugging prints into your code as such:

    //Check if the http version is "HTTP/1.1"
if(strcasecmp(check_request[2], "HTTP/1.1") != 0)
{
    for (int i = 0, n = strlen(check_request[2]); i < n; i++)
        printf("%i:'%i' ", i,check_request[2][i]);
    
    printf("505 HTTP Version Not Supported\n");
    continue;     
}

(used %i to get the decimal values so non-printable chars will be easier to see)

You will discover that check_request[2] is indeed not "HTTP/1.1"

jharvard@appliance (~/Dropbox/CS50x/2015/pset6): ./server -p 8080 public
Using /home/jharvard/Dropbox/CS50x/2015/pset6/public for server's root
Listening on port 8080
GET /cat.html HTTP/1.1
0:'72' 1:'84' 2:'84' 3:'80' 4:'47' 5:'49' 6:'46' 7:'49' 8:'13' 9:'10' 
505 HTTP Version Not Supported

In ASCII:

72 84 84 80 47 49 46 49 13 10
H  T  T  P  /  1  .  1  CR LF  

The carriage return and line feed must be stripped from the check_request[2] string in order for your strcasecmp to match.