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Functions

Wordwrap long text string using "\n"

Terminal - Wordwrap long text string using "\n"
fold -sw 20 <(echo "Long Text to be wrapped with \"\n\"") |sed ':a;N;$!ba;s/ *\n/\\n/g'
2015-04-16 21:06:53
User: alecthegeek
Functions: echo fold sed
1
Wordwrap long text string using "\n"

I used this fragment with Imagemagick convert so that I can place long text strings in pictures. The "\n" gets converted to a true newline in the image.

So this fragment uses fold command to wrap the line and then sed to convert newlines (and any trailing spaces on the line) to the text "\n"

Alternatives

There are 3 alternatives - vote for the best!

Terminal - Alternatives

Know a better way?

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What others think

That's nice bit of sed. Would you like to explain how it works?

Comment by flatcap 139 weeks and 3 days ago

So 1st off I just copied it from the net so I can't take credit.

How does it work?

1) It's four sed command ":a", "N" "$!ba" and 's/ *\n"/\\n/g'

":a" defines a label for a later jump command

"N" Read all the next line to the pattern space. Exit loop if no more text

"$!ba" Branch to label if NOT at end of file

"s/ *\n"/\\n/g" Find all instance of a real newline char, optionally proceeded by one or more spaces, and replace with the literal "\" followed by an "n". Do it for all occurrences in the pattern space

It could be done more simply with tr, but that does not handle the spaces preceding the newline char

Comment by alecthegeek 139 weeks and 3 days ago

Thanks for the explanation.

> It could be done more simply with tr

That's the first thing that I thought, but it doesn't work.

tr does a one-to-one character replacement.

... | tr '\n' '\\n'

replaces newlines with backslash only.

Comment by flatcap 139 weeks and 3 days ago

Your point of view

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