fft — Form feed-terminated text files.
fft is a filetype where the string \f\n acts as a separator. Thus it
can be used to store a list of contents that do not themself contain the
string \f\n.
fft is supposed to work well with Unix-style text files (henceforth just “text files”). Such a file is defined as:
A file that contains characters organized into zero or more lines.
And a “line” is defined as:
A sequence of zero or more non-<newline> characters plus a terminating <newline> character.
Conceptually, a fft file should be able to store a list of contents which could be text files in their own right.
Terminology
Terminator. The string \f\n. Used to terminate sections.
Section. A piece of text terminated by terminator. An fft file consists of zero or more sections.
Length of file. The length of a fft file is the number of sections that it contains.
Empty file. An fft file that contains no characters. Equivalent to an empty text file.
Well-formed fft files
A well-formed fft file:
- Is either empty or consists of one or more sections.
- Contains no more than one empty sections, that is, a section with no content.
- Since all sections need to be terminated, the last string in a well-formed non-empty fft file is the terminator.