Insert line

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1

Hello

Is there any sed command to insert a line after nth line... have a file of 500000 lines

Thanks

2

Hello,

Here is an awk example for same, it may help.
For example an input file is:

1  5
2  4
3  3

Code is:

awk 'NR==2 {print "checking the insertion."} 1' file_name

Output will be as follows.

1  5
checking the insertion.
2  4
3  3

Thanks,
R. Singh

3

Insert line after every 7th line:

sed -n 'p;n;p;n;p;n;p;n;p;n;p;n;p;i\inserted line' file_1 >file_2
4

Try sed with �i� command to insert a line before match for your request to add only one line.

$ cat file.txt
1
2
3
4
5

$  sed "4 i\Inserted new line" file.txt
1
2
3
Inserted new line
4
5
5

Thank you all for the replies

I ended up writing a small fortran code to do the insertion I was looking for by using

m = 90000
n = 288
do i = 1, m
 do j = 1, n
read() original file
write() to the new file
end do
insert line
enddo