Question

How to retrieve a single line from the file?

file.txt
"aaaaaaa"
"bbbbbbb"
"ccccccc"
"ddddddd"

I need to retrieve the line 3 (“ccccccc”)
Thank you.

Answer 1

If you know you need line 3, one approach is to use head to get the first three lines, and tail to get only the last of these:

varname="$(head -n 3 file.txt | tail -n 1)"

Another approach, using only Bash builtins, is to call read three times:

{ read ; read ; IFS= read -r varname } < file.txt