GoServe: FILE command

FILE command

Syntax:

  FILE [ERASE] [TYPE content-type] [BINARY|TEXT] [NOCACHE] NAME filespec

The file named by 'filespec' will be sent to the client. 'filespec' should normally be a fully qualified name (if it is not, GoServe would look for it in the GoServe working directory). Either forward or backward slashes may be used as directory separators; the OS/2 file systems accept either.

After this command has ended, the connection to the client is closed, so this is a 'completion command'.

The optional keywords may be specified, in any order, and have the following effects:

ERASE -- the file is a temporary file, and should be erased after being sent. [The transaction number and port can be used for generating a safe name for a temporary file.]
TYPE -- [HTTP protocol only] the file will be prefixed by an HTTP "OK" response line and an HTTP header, including the content length derived from measuring the file. The value of the TYPE option ('content-type') should be a Internet Media Type such as "text/html" or "image/gif". See notes below for more information.
The TYPE option may only be used if GoServe is started with the HTTP parameter (HTTP headers are not used by Gopher), and should normally always be used when running as a Web server.
BINARY -- [default for HTTP] the file is a binary file, and forms the entire response to the client. GoServe will close the TCP/IP connection as soon as the complete file has been sent.
A Gopher server should use this option for all files that are not simple text or menus, for example ".ZIP" files, etc.
TEXT -- [default for Gopher] the file is a text file: any trailing DOS end-of-file character will not be sent to the client.
If running as a Gopher server, a Gopher terminator line (just a period) will be sent at the end of the document, before the connection is closed.
NOCACHE -- prevents this FILE command being cached (that is, this command will not be associated with a request). See "File command cache" for more details.

Here are some examples:

Returning an HTML file to a Web client:

  file type text/html name d:/gohttp/index.htm

Returning a temporary image file to a Web client:

  file erase type image/gif name d:/gohttp/$7681.80

Returning a .ZIP file to a Gopher client:

  file binary name d:/gogopher/gogopher.zip

Notes:

The filespec may not include an 'upwards reference' sequence ("..\" or "../"), as such a sequence could possibly allow clients access to any file on the server machine.
All data sent to a client with an HTTP header should be described by a Content-Type field in the header; GoServe will therefore only generate a header automatically if the TYPE option was specified or the HEADER command has been used to add header lines. In this latter case, it is the responsibility of the filter to supply the Content-Type field if the TYPE option was not used.
Internet Media Types were formerly known as MIME (Multipurpose Internet Mail Extensions) Content Types. MIME is described in RFC 1521 and RFC 1522. The media types are used in the HTTP protocol so that clients can determine how to process data received from servers. Some common types are listed in the sample filter.

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