removing blank lines in a text file

christianunix · 10-25-2007, 03:32 PM

how do I delete all blank lines in a text file? thanks

bjagee · 10-25-2007, 03:36 PM

There are a thousand ways to do that. If you want to do it from the ci:

Code:

     cat file-blanklines-2-be-deleted | sed -e '/^$/d' | tee newfile-no-blanklines

Or, if you prefer vi/vim:

Code:

     :g/^[ t]*$/d  --> WHERE t=tab

weibullguy · 10-25-2007, 03:37 PM

Look at table C-2 --> http://tldp.org/LDP/abs/html/abs-guide.html#AEN20423

The_JinJ · 10-25-2007, 03:38 PM

Used this in the past to strip blank lines and comments

Code:

sed '/ *#/d; /^ *$/d' test.txt2

0.o · 10-25-2007, 03:39 PM

Why couldn't you just use: sed /^$/d < oldfile > newfile

complich8 · 10-25-2007, 03:46 PM

I prefer grep:
#print only lines that contain non-whitespace characters
grep '[^[:space:]]' oldfile > newfile

ghostdog74 · 10-25-2007, 06:39 PM

Quote:

Originally Posted by bjagee

There are a thousand ways to do that. If you want to do it from the ci:

Code:

     cat file-blanklines-2-be-deleted | sed -e '/^$/d' | tee newfile-no-blanklines

you can skin the cat

Code:

sed -e '/^$/d' file-blanklines-2-be-deleted

and if your sed supports -i option

Code:

sed -ie '/^$/d' file-blanklines-2-be-deleted

custangro · 10-25-2007, 06:42 PM

or vi the file and in command mode do this:

Code:

%s/ //g

bjagee · 10-26-2007, 12:46 PM

Quote:

Originally Posted by custangro

or vi the file and in command mode do this:

Code:

%s/ //g

That will only eliminate spaces, and it will do so in sentences too. You would still have blank lines and tabsbutyourwordswouldallruntogether.

matthewg42 · 10-26-2007, 01:28 PM

If you want to modify the original file (instead of creating a second, modified one), you can use the -i option. This version also deletes lines with spaces and tabs on... maybe you want to keep them, I don't know:

Code:

sed -i '/^[ \t]*$/d' the_file_to_modify

custangro · 10-26-2007, 02:52 PM

Quote:

Originally Posted by bjagee

That will only eliminate spaces, and it will do so in sentences too. You would still have blank lines and tabsbutyourwordswouldallruntogether.

Sorry, I miss understood the question, the correct syntax is this (in vi command mode):

Code:

g/^$/d

-custangro

bjagee · 10-29-2007, 12:24 AM

That's the ticket. You could also use \s in that to get lines that have non-printing chars:

Code:

: %s:\s:g