Line wrapping utilities, Linux fmt -s equivalent

E

eldaemon

I'm looking for a better way to wrap lines. I have Markdown Hugo source to my website and haven't been wrapping the lines for a while. One of the problems I ran into was things like lists getting messed up if I formatted with fmt.

For example:

Code: 
please wrap this really long set of words. one two, three, four, five; six, seven, eight

1. don't
2. wrap
3. this

aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa

Becomes:

Code: 
please wrap this really long set of words. one two, three, four,
five; six, seven, eight

1. don't 2. wrap 3. this

aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa

I'd like to keep the 1, 2, 3, all on separate lines but wrap the first line (as it does) and leave the last line alone (as it also does).

So effectively, only splitting a line if it's longer than the maximum.

fold does this, but it's a hard wrap that doesn't account for words. So it will split a word in half.

fmt on Linux has a -s argument that tells it not to split lines shorter than the maximum. It operates exactly how I would hope.

On FreeBSD, -s is a whitespace collapsing argument. If -s wasn't used on FreeBSD, I'd be tempted to rewrite the feature and just use -s. I could still do it with a different argument name, although not certain which one.

Is there another utility which does this? Maybe something in Ports? If I did write a patch for FreeBSD's fmt, do you think it would be accepted? What should the argument name be? Or should I write something new altogether?

Thank you for your time.
 
Linux fmt (as well as gfmt()) with -s option doesn't perform the required functionality, e.g. this file:
Code: 
please wrap this really long set of words. one two, three, four, five; six, seven, eight
 
1. don't
2. wrap
3. this

please wrap this really long set of words. one two, three, four, five; six, seven, eight
please wrap this really long set of words. one two, three, four, five; six, seven, eight
please wrap this really long set of words. one two, three, four, five; six, seven, eight
becomes:
Code: 
% gfmt -s foo
please wrap this really long set of words. one two, three, four, five;
six, seven, eight

1. don't
2. wrap
3. this

please wrap this really long set of words. one two, three, four, five;
six, seven, eight
please wrap this really long set of words. one two, three, four, five;
six, seven, eight
please wrap this really long set of words. one two, three, four, five;
six, seven, eight
The multiple long lines are split, but not joined, the idea of formatting is lost. Maybe in your particular case it's okay, but IMO that option is useless since can be achieved with a simple sed() script:
Code: 
#!/bin/sh
 
GOAL=65
MAX=10
sed 's/\(.\{'$GOAL'\}[^\ ]\{0,'$MAX'\}\ \)\(.*\)$/\1\
\2/' $1
 
aragats, I'm not sure it's possible to support lines like 1. test, 2. test, etc, and still have line joining.

The nice thing is that if you have formatted your file, it makes it a bit more idempotent. I'm looking for something I can run safely and always have sane output without having to look it over carefully, even if some lines are shorter than they could be.

Interesting sed script though, haven't tried that yet.
 
eldaemon said:
I'm not sure it's possible to support lines like 1. test, 2. test, etc, and still have line joining.
Click to expand...
I agree. The arithmetic list items need to be easily identifiable for fmt(1).

If you indent the arithmetic list items and separate them with a newline, then fmt -$MAX -p will do the job you want.
Code: 
please wrap this really long set of words. one two, three, four, five; six, seven, eight
 
  1. don't wrap this very long list item to join the next arithmetic list item because I don't want that;

  2. wrap; and

  3. this.

please wrap this really long set of words. one two, three, four, five; six, seven, eight
please wrap this really long set of words. one two, three, four, five; six, seven, eight
please wrap this really long set of words. one two, three, four, five; six, seven, eight
Code: 
$ fmt -60 -p
please wrap this really long set of words. one two, three,
four, five; six, seven, eight

  1. don't wrap this very long list item to join the next
  list item because I don't want that;

  2. wrap; and

  3. this.

please wrap this really long set of words. one two, three,
four, five; six, seven, eight please wrap this really long
set of words. one two, three, four, five; six, seven, eight
please wrap this really long set of words. one two, three,
four, five; six, seven, eight
You could use sed for pre- and post- processing of the arithmetic list items to achieve the outcome you want.
 
On re-reading your original post, I'm not sure if this is what you want. Maybe it progresses the discussion.
 
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