Split text file into short lines for reading

text processing

Is there a program that can take a plain-text file with long lines, and add a newline after a certain number of characters, only splitting at words, to make it readable? For example, take this:

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Aliquam vel lectus ac enim venenatis porttitor in et est. Curabitur ut eros quis risus consequat dictum a a lectus. Integer ut risus quis augue lobortis molestie vel id nibh. Aliquam sit amet mattis lorem, vel ornare felis. Donec pulvinar tempus lorem, at porta sem pretium ut. Cras ut lorem tincidunt, scelerisque nunc vitae, posuere augue. Vestibulum iaculis libero id congue ultrices. Nullam mauris ipsum, aliquet eget nisl non, venenatis euismod enim. Phasellus a eleifend velit. Aenean molestie venenatis turpis, consectetur convallis velit fringilla non.

And turn it into this:

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Aliquam vel
lectus ac enim venenatis porttitor in et est. Curabitur ut eros quis
risus consequat dictum a a lectus. Integer ut risus quis augue lobortis
molestie vel id nibh. Aliquam sit amet mattis lorem, vel ornare felis.
Donec pulvinar tempus lorem, at porta sem pretium ut. Cras ut lorem
tincidunt, scelerisque nunc vitae, posuere augue. Vestibulum iaculis
libero id congue ultrices. Nullam mauris ipsum, aliquet eget nisl non,
venenatis euismod enim. Phasellus a eleifend velit. Aenean molestie
venenatis turpis, consectetur convallis velit fringilla non.

Best Answer

The command I think you're looking for is called fmt.

$ fmt loremipsum.txt
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Aliquam vel
lectus ac enim venenatis porttitor in et est. Curabitur ut eros quis risus
consequat dictum a a lectus. Integer ut risus quis augue lobortis molestie
vel id nibh. Aliquam sit amet mattis lorem, vel ornare felis. Donec
pulvinar tempus lorem, at porta sem pretium ut. Cras ut lorem tincidunt,
scelerisque nunc vitae, posuere augue. Vestibulum iaculis libero id congue
ultrices. Nullam mauris ipsum, aliquet eget nisl non, venenatis euismod
enim. Phasellus a eleifend velit. Aenean molestie venenatis turpis,
consectetur convallis velit fringilla non.

You can control the results, such as width, etc.

$ fmt --help
Usage: fmt [-WIDTH] [OPTION]... [FILE]...
Reformat each paragraph in the FILE(s), writing to standard output.
The option -WIDTH is an abbreviated form of --width=DIGITS.

Mandatory arguments to long options are mandatory for short options too.
  -c, --crown-margin        preserve indentation of first two lines
  -p, --prefix=STRING       reformat only lines beginning with STRING,
                              reattaching the prefix to reformatted lines
  -s, --split-only          split long lines, but do not refill
  -t, --tagged-paragraph    indentation of first line different from second
  -u, --uniform-spacing     one space between words, two after sentences
  -w, --width=WIDTH         maximum line width (default of 75 columns)
      --help     display this help and exit
      --version  output version information and exit

With no FILE, or when FILE is -, read standard input.

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And here's a nice, simple, gawk one-liner :

$ gawk '/^\[/{match($0, /^\[ (.+?) \]/, k)} {print >k[1]".txt" }' entry.txt

This will work for any file size, irrespective of the number of lines in each entry, as long as each entry header looks like [ blahblah blah blah ]. Notice the space just after the opening [ and just before the closing ].

EXPLANATION:

awk and gawk read an input file line by line. As each line is read, its contents are saved in the $0 variable. Here, we are telling gawk to match anything within square brackets, and save its match into the array k.

So, every time that regular expression is matched, that is, for every header in your file, k[1] will have the matched region of the line. Namely, "entry1", "entry2" or "entry3" or "entryN".

Finally, we print each line into a file called <whatever value k currently has>.txt, ie entry1.txt, entry2.txt ... entryN.txt.

This method will be much faster than perl for larger files.

How to split a text file based on the content into multiple text files

awk '/^4153/ {print >"CAMS1.TXT"; next} {print >"CAMS2.TXT"}' CAMS.TXT

There are other ways to do that, another would be using two grep commands

grep "^4153" CAMS.TXT > CAMS1.TXT
grep -v "^4153" CAMS.TXT > CAMS2.TXT

That's less efficient but easier to type, after the first grep is done, you recall it from your shell history (using the "up" arrow key) and makes a few changes. Of course the file is read two times, so don't do that if it is huge.

Best Answer

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Text Processing – How to Split a Text File into Multiple Files

How to split a text file based on the content into multiple text files

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