How to remove the empty lines in a file in linux

Question

I have an output in a file with the blank spaces like

daily/A3D05180000052121001 30698

daily/A3D05180000052200001 30698

daily/A3D05180000052203001 30698

I need to remove the empty lines and my output should be like

daily/A3D05180000052121001 30698
daily/A3D05180000052200001 30698
daily/A3D05180000052203001 30698

I tried using sed

sed -i -e '/./,$!d' -e :a -e '/^\n*$/{$d;N;ba' -e '}' "$FILESIZE3"

But it did not work out... Can anyone pls help me out on this

Are the lines completely empty, or may there be spaces and/or tabs on them? — Kusalananda, May 19 '20 at 08:59
@Kusalananda I had some content and i deleted those contents and saved in the file...So the place where i removed the contents empty spaces came — clarie, May 19 '20 at 09:01
@clarie Sorry, but that's ever so slightly ambiguous. Are there spaces on the otherwise empty lines? Also, is the file saved with a Windows editor, i.e. is it a DOS text file? — Kusalananda, May 19 '20 at 09:05
@clarie If you don't understand what Kusalananda asked you, you can use cat -E file to display the file's content in a way that we can see if empty lines are indeed empty or if they have spaces. — Quasímodo, May 19 '20 at 10:40

Kusalananda · Answer 1 · 2023-10-10T12:16:03.657

sed '/^[[:space:]]*$/d' file >file.modified

This would delete all lines of file that are entirely empty or only contain space-like characters. Space-like characters would in this context include carriage-return characters found at the end of each line in DOS text files (when processed by Unix tools), tabs, and spaces. The resulting data would be written to file.modified.

Removing the redirection and instead using the -i option would do an "in-place" modification of file instead of writing to a new file, but be aware that this option is non-portable and may work differently on different Unix systems (How can I achieve portability with sed -i (in-place editing)?).

score 0 · Answer 2 · answered May 19 '20 at 08:51

0

Not sure what the rest of your sed does but isn't this what you're looking for?

host:~ # sed -e '/^$/d' file.txt
daily/A3D05180000052121001 30698
daily/A3D05180000052200001 30698
daily/A3D05180000052203001 30698

Please clarify the requirement if this doesn't do the trick.

answered May 19 '20 at 08:51

eblock

966

sed -i -e '/^$/d' "$FILESIZE3" I gave like this...it didn't work. I added -i to edit file inplace...can u help me on this – clarie May 19 '20 at 09:00

score 0 · Answer 3 · answered May 19 '20 at 09:32

0

AWK representation :

awk '!/^$/{ print }' infile > outfile && mv outfile infile

answered May 19 '20 at 09:32

Stalin Vignesh Kumar

1,755
6
15

score 0 · Answer 4 · answered May 19 '20 at 09:36

In vim, I use the global command to remove empty lines. Not sure if it helps in your case.

#:[range]g/pattern/cmd

The example acts on the specified [range] (default whole file), by executing the command cmd for each line matching pattern (an executing command is one starting with a colon such as :d for delete in vi). In your case it can be

:g/^$/d

If you have spaces or tabs in between

:g/^[\s\t]*$/d

Hope it helps.

How to remove the empty lines in a file in linux

4 Answers4