Indenting Fold (ifold)

Indenting fold (ifold) is a replacement for the UNIX fold command, written in Haskell. It indents every wrapped line by the same amount that the original line was indented. This is useful, e.g. for converting plain-text documents into other formats.

Example usage

The normal UNIX fold command looks like this:

> echo -e "\nThis is a test of the UNIX fold utility.\n\n\tNotice that indented paragraphs don't get inden
ted as a whole." | fold -s -w 20

This is a test of 
the UNIX fold 
utility.

        Notice that 
indented paragraphs 
don't get indented 
as a whole.

Using ifold instead will produce the following:

> echo -e "\nThis is a test of the ifold utility.\n\n\tNotice that indented paragraphs will be indented as
a whole." | ifold 20

This is a test of
the ifold utility.

        Notice that
        indented
        paragraphs
        will be
        indented as
        a whole.

This behavior matches the display behavior of many text editors operating in word-wrap mode. This means that using ifold to format your file will lead to it resembling its display in your text editor much more closely.

I've personally used ifold to format class notes which I take in plain text format and wanted to print. It was this use case which brought upon the creation of the utility, but I anticipate that there are other useful ways to use ifold as well.

Bug reports, suggestions, questions, comments — they are welcome!