Linux: sed - Delete a line

As we discussed in the above section about the power of SED command, here we discuss about the how to use SED command to delete a line in a file.

How to delete first line using SED command

sed 'Nd' sample1.txt

Note: ‘N’should be replaced with the line number which we want to delete 

           ‘d’ is the command used to delete.

How to delete a particular line using SED command

sed '4d' sample1.txt

How delete last line in a file using SED command

sed '$d' sample1.txt

Note: ‘$ ‘indicates the last line of a file

In the next article will learn more about SED commands.

Delete all spaces in front of every line of file.txt

sed 's/^[ ^t]*//' file.txt

Delete all spaces at the end of every line of file.txt

sed 's/[ ^t]*$//' file.txt

Delete all spaces in front and at the end of every line of file.txt

sed 's/^[ ^t]*//;s/[ ^]*$//' file.txt

Delete all consecutive blank lines except for EOF sed '/./,/^$/!d' file.txt

Delete all consecutive blank lines, but allows only top blank line

sed '/^$/N;/\n$/D' file.txt

Delete all leading blank lines
sed '/./,$!d' file.txt

Delete all trailing blank lines

sed -e :a -e '/^\n*$/{$d;N;};/\n$/ba' \file.txt

Delete every third line, starting with the first sed '1~3d' file.txt Delete only the first match sed '0,/RE/{//d;}' file.txt Delete lines matching pattern sed '/pattern/d' file.txt Delete all blank lines from a file sed '/./!d' file.txt Delete all consecutive blank lines except for the first two sed '/^$/N;/\n$/N;//D' file.txt Delete the last line of each paragraph sed -n '/^$/{p;h;};/./{x;/./p;}'\ file.txt