Question

I’m trying to insert a line of text after the very last empty line in the middle of a file.

Example file:

some text
more text

blah blah blah
more blah

some more text
and even more text

The inserted text should be on line 6 for that file. I tried commands like this so far:

sed '/\n/ i some text' file

But, so far nothing has worked. Any ideas? Thanks.

Answer 1

A different solution with grep and awk:

awk -v last_empty_line=$(grep -nE '^[[:blank:]]*$' your_file | tail -1 | cut -c 1) '{print; if (NR==last_empty_line) print "->some new text here"}' your_file

awk inserts your new text after the last empty line; the index of the last empty line is selected with a proper grep which finds empty lines (or filled only with blank characters), piped into a tail to select the last one.