What is the meaning of a txt file? Parallels between the XML SchemahexBi

[Roger L Costello <costello@mitre.org>]

Hi Folks,

Yesterday a colleague asked me for "data". When I asked what kind of data, she said, "txt files".

That got me to thinking, "What is a txt file?" Here are some thoughts.

The format of data in a txt file is unspecified. Contrast that to the format of a JPEG file which is well-known and specified by the JPEG specification. The format of an HTML file is well-known and specified by the HTML specification. Likewise for PPT, DOC, XML, JSON, CSV, and thousands of others. But a txt file has no inherent format; if you are given an arbitrary txt file, all you know is that it holds bytes that can be rendered as character symbols. 

A JPEG file has, in a sense, a meaning: it is an image. A HTML file has a meaning: it is a web page. A PPT file has a meaning: it is a set of slides. But what is the meaning of a txt file? It has no preordained meaning. In a sense, a txt file is meaningless. A txt file is the most primitive of text files. 

Note that just because a txt file is meaningless, does not imply it is useless. Txt files are useful in those cases where you have a grab bag of data that you want stored and possibly transported.

I see similarities between txt files and the XSD hexBinary type. Both are at the bottom (the most primitive) with respect to meaning. Neither can be interpreted without additional information.

I welcome your comments.

/Roger