simulate an HTTP request with curl

I'm trying to debug an HTTP request that produces an error on our server. However, I'm struggling to reproduce the exact request somehow.

On my nginx logs, I see this entry which generated the error

157.55.33.20 - - [22/Nov/2013:04:06:22 +0000] "GET /en/library/search?utf8=\xE2\x9C\x93&q=something HTTP/1.1" 500 0 "-" "Mozilla/5.0 (compatible; bingbot/2.0; +http://www.bing.com/bingbot.htm)" "-"

However, trying to use curl or httpie using the same string produces log entries like:

GET /en/library/search?utf8=\x5CxE2\x5Cx9C\x5Cx93&q=something

GET /en/library/search?utf8=xE2x9Cx93&q=something

GET /en/library/search?utf8=%5CxE2%5Cx9C%5Cx93&q=something

I just can't seem to reproduce the exact same request. I tried with various command-line parameters, but can't figure this one out.

Any suggestions on how to reproduce the exact same request?

Solution

You can create HTTP requests with greater freedom with telnet. To start a connection, type this at the command line:

telnet www.example.com 80

(Here, 80 corresponds to the port number for HTTP requests). Once you're connected, you'll see a message like this:

Trying 12.34.56.78...
Connected to www.example.com.
Escape character is '^]'.

You can then type in your request, e.g.:

GET /en/library/search?utf8=\xE2\x9C\x93&q=something HTTP/1.1
Host: www.example.com
User-Agent: Mozilla/5.0 (compatible; bingbot/2.0; +http://www.bing.com/bingbot.htm)
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8

Finish with two carriage returns to mark the end of the header.

EDIT: lcornea's suggestion is also worth considering. If your command line terminal accepts UTF8 (type in echo $LANG to find out), then type (or paste) the character ✓ (check mark) instead of the three escaped characters. Or on a Windows Latin-1 terminal, type in âœ“ instead.