Shell – Reading lines from a file based on a list of line numbers and writing output to a utility

Have you tried nl -b a <file_name>

debian@virt00:~/test$ nl -b a file
     1  abcdef
     2   ghi
     3
     4   klm
     5   nopqr st
debian@virt00:~/test$

• nl stands for number line
• -b flag for body numbering
• 'a' for all lines.

for more information http://linux.die.net/man/1/nl

You can use sed within a loop over each file in your current folder. You extract the relevant parts and append them via >> to a file named file like this:

for files in *; \
do sed -n -e '/^From file/ H;' \
          -e '/Ratio of morphemes over utterances/ {H; x; s/\n//g; s/From file <\(.*\)>.*Ratio of morphemes over utterances = \([0-9]*\.[0-9]*\).*/\1:    \2/g; p;}' "$files";
done >>file