how to rejoin words that are split accross lines with a hyphen in a text file - regex

Question

OCR texts often have words that flow from one line to another with a hyphen at the end of the first line. (ie: the word has '-\n' inserted in it).
I would like rejoin all such split words in a text file (in a linux environment).
I believe this should be possible with sed or awk, but the syntax for these is dark magic to me! I knew a text editor in windows that did regex search/replace with newlines in the search expression, but am unaware of such in linux.

Answer 1

Make sure to back up ocr_file before running as this command will modify the contents of ocr_file:
perl -i~ -e 'BEGIN{$/=undef} ($f=<>) =~ s#-\s*\n\s*(\S+)#$1\n#mg; print $f' ocr_file

Answer 2

This answer is relevant, because I want the words joined together... not just a removal of the dash character.
cat file| perl -CS -pe's/-\n//'|fmt -w52
is the short answer, but uses fmt to reform paragraphs after the paragraphs were mangled by perl.
without fmt, you can do
#!/usr/bin/perl
use open qw(:std :utf8);
undef $/; $_=<>;
s/-\n(\w+\W+)\s*/$1\n/sg;
print;
also, if you're doing OCR, you can use this perl one-liner to convert unicode utf-8 dashes to ascii dash characters. note the -CS option to tell perl about utf-8.
# 0x2009 - 0x2015 em-dashes to ascii dash
perl -CS -pe 'tr/\x{2009}\x{2010}\x{2011}\x{2012\x{2013}\x{2014}\x{2015}/-/'

Answer 3

cat file | perl -p -e 's/-\n//'
If the file has windows line endings, you'll need to catch the cr-lf with something like:
cat file | perl -p -e 's/-\s\n//'

Answer 4

Hey this is my first answer post, here goes:
'-\n' I suspect are the line-feed characters. You can use sed to remove these. You could try the following as a test:
1) create a test file:
echo "hello this is a test -\n" > testfile
2) check the file has the expected contents:
cat testfile
3) test the sed command, this sends the edited text stream to standard out (ie your active console window) without overwriting anything:
sed 's/-\\n//g' testfile
(you should just see 'hello this is a test file' printed to the console without the '-\n')
If I build up the command:
a) First off you have the sed command itself:
sed
b) Secondly the expression and sed specific controls need to be in quotations:
sed 'sedcontrols+regex' (the text in quotations isn't what you'll actually enter, we'll fill this in as we go along)
c) Specify the file you are reading from:
sed 'sedcontrols+regex' testfile
d) To delete the string in question, sed needs to be told to substitute the unwanted characters with nothing (null,zero), so you use 's' to substitute, forward-slash, then the unwanted string (more on that in a sec), then forward-slash again, then nothing (what it's being substituted with), then forward-slash, and then the scale (as in do you want to apply the edit to a single line or more). In this case I will select 'g' which represents global, as in the whole text file. So now we have:
sed 's/regex//g' testfile
e) We need to add in the unwanted string but it gets confusing because if there is a slash in your string, it needs to be escaped out using a back-slash. So, the unwanted string
-\n ends up looking like -\\n
We can output the edited text stream to stdout as follows:
sed 's/-\\n//g' testfile
To save the results without overwriting anything (assuming testfile2 doesn't exist) we can redirect the output to a file:
sed 's/-\\n//g' testfile >testfile2

Answer 5

sed -z 's/-\n//' file_with_hyphens