posted 11 years ago
There is by the way no such thing as "the content type" of a file per se.
There exists a funny file format: a portion of C code with data which can also be considered as an image. Is such a file a piece of plain text, C source, C++ source or an image file?
There exists the file naming convention that the last portion of a file's name (the one after the dot - also called "extension") hints on the content.
Web servers can be configured how to map these "extensions" to content-types.