Command
The command field is subdivided in three parts, operation, URL, and protocol/version.
Operation
What is is.
The operation used in the request.
What it says.
It tells you what operation has been requested. The HTTP protocol which is used to access a web server supports (in version 1.1) the following operations:
- GET - Get the URL (which is the "normal" case)
- HEAD - Get HTTP header information for an URL (often used by caches to determine if a page is up to date)
- POST - Submit form data to the server (i.e., to a CGI program)
- CONNECT - Request switching to a secure connection via SSL (this is something for proxies)
- PUT - Upload a page to the server (rarely seen if at all)
- OPTIONS - Request communications options
- DELETE - Delete the URL
- TRACE - Request a trace message
The direction of transfer depends on the operation. GET, HEAD, CONNECT, OPTIONS, and TRACE request information from the server. POST and PUT transfer information to the server. DELETE involves no data transfer.
What may cause trouble.
Nothing that I'm aware of.
URL
What is is.
The requested URL.
What it says.
It tells you which URL has been requested from the server, which arguably is the single most important information in the log file. Counting accesses gives you the number of "hits" for an URL.
If the URL resides on the server, the URL doesn't contains the server name (i.e., "/index.html"). If the web server is expected to act as a proxy and fetch the page from another web server, the URL is complete with protocol and server name (i.e., "http://www.sun.com/index.html").
What may cause trouble.
You might want to check if proxy requests are made (and served!) though you don't want your server to be used as a proxy. In this case, disable the proxy function in the server configuration.
Protocol
What is is.
The protocol that has been used to make the request.
What it says.
It tells you the protocol and protocol version used in the request. The very first version of HTTP (0.9) will appear without version information. The current version (as of 2002) is HTTP 1.1. Still, version 1.0 probably will make up half of the requests you receive.
More on dynamic pages?
What may cause trouble.
Nothing really.
© 1998-2005 Christian Treber, ct@ctreber.com
. All rights reserved. The author takes no responsability for linked external pages, the content of which by no means reflect his own opinion, convictions etc.