Question

Is there a shell command to pick the n-th line of a string ?

Example:

line1
line2
line3

pick line 2.

UPDATE: Thank you so far. With your help, I came up with this solution for a string:

Pick the 2nd line:

echo -e "1\n2\n3" | head -2 | tail -1

Answer 1

$ head -n filename | tail -1

where ‘n’ is your line number. But it’s a little inefficient, launching 2 processes.

Alternatively sed can do this. To print the 4th line:

$ sed -n 4p filename

This forum answer details 3 different methods for sed

# print line number 52
sed -n '52p' # method 1
sed '52!d' # method 2
sed '52q;d' # method 3, efficient on large files