Sed problem

Shell Programming and Scripting
1

Hi again!

Sed is very difficult to understand for me... :frowning:

I have a file like this

And I'm looking for this result

I found sed '$!N;s/\n/ /' => Put Line1 and Line2 together, Line3 and Line4...
I tried |sed '$!N;s/\n*\n/ /' but it didn't work...

Thanks for your help

PS:And if you have a nice documentation which explain sed with a lot of examples, because I really prefere to find the solution by myself...:wink:

2

It's regular expressions which give pople the most problems with sed -
see Dale Dougherty & Arnold Robbins 'sed & awk' book.

Actually awk works pretty well for your problem

awk ' NR%3 {printf("%s", $0); next}
        !NR%3 {print $0} ' inputfile > newfile

which means

  1. if the line number % 3 is not zero print the line with no carriage return; skip to next line
  2. if the line number % 3 is zero print the line with a carriage return
3

Another one:

pr -3tas file.txt | sed 's/\t//g'
4 
paste -d" " - - - < file
5 
awk '{ORS=(NR%3)?S:RS}1' infile

Use gawk, nawk or /usr/xpg4/bin/awk on Solaris.

6

Hi, Castelior:

If no space is desired between lines:

sed '$!N;$!N;s/\n//g'

If you want a space between joined lines:

sed '$!N;$!N;s/\n/ /g'

or

sed '$!N;$!N;y/\n/ /'

Regards,
Alister

---------- Post updated at 02:44 PM ---------- Previous update was at 02:33 PM ----------

Woops! I just noticed that bit. Sorry for spoiling it for you. This link may help you in learning SED Sed - An Introduction and Tutorial

Best of luck,
Alister

7

Thanks everyone!

I gonna test it!

---------- Post updated at 08:43 AM ---------- Previous update was at 08:41 AM ----------

It looks great!!!:b: thank you so much!:smiley: