This question asks about wrapping text at a certain column, and people suggest using fold or fmt but as far as I can see, these simply count characters and don't allow for non-printing characters. For example:
fold -w 20 -s <<<`seq 1 25`
as one might expect, produces:
1 2 3 4 5 6 7 8 9
10 11 12 13 14 15
16 17 18 19 20 21
22 23 24 25
but:
fold -w 20 -s <<<^[[32m`seq 1 25`^[[m
(where ^[ is the escape character) intuitively ought to produce the same thing in green text, but instead produces:
1 2 3 4 5 6 7
8 9 10 11 12 13 14
15 16 17 18 19 20
21 22 23 24 25
in green text.
I can't see any switches that say to account for non-printing characters, and the PS1 approach to flagging non-printing characters doesn't seem to work with fold or fmt.
Is there something (ideally something standard) that can wrap text whilst accounting for non-printable characters?
EDIT:
The example above is really to simplify and demonstrate the problem but I may have over-simplified. To clarify my real-world example, I've got text where some words are in colour (using ANSI escape sequences) and I'd like that to wrap neatly. For example:
Here is some example text that contains ^[[31mred^[[m and ^[[32mgreen^[[m words that I would like to wrap neatly.
where ^[ is the escape character.
If I wanted this to wrap to 20 columns, I would expect:
Here is some
example text that
contains red and
green words that
I would like to
wrap neatly.
(with "red" and "green" in colour) but because of the ANSI escape codes, it wraps thus:
Here is some
example text
that contains
red and
green words
that I would like
to wrap neatly.
Best Answer
The ANSI escape sequence is being interpreted by the shell, not by the piping. So you're really inserting the text
^[[32malongside with your sequence-output into you fold-command. If you want the whole text in green, you could try something like this:or
Note that I'm using the
\eas the escape character. This works directly within bash shells for testing.