#!/bin/bash
# lastpipe-option.sh

line=''                   # Null value.
echo "\$line = "$line""   # $line =

echo

shopt -s lastpipe         # Error on Bash version -lt 4.2.
echo "Exit status of attempting to set \"lastpipe\" option is $?"
#     1 if Bash version -lt 4.2, 0 otherwise.

echo

head -1 $0 | read line    # Pipe the first line of the script to read.
#            ^^^^^^^^^      Not in a subshell!!!

echo "\$line = "$line""
# Older Bash releases       $line =
# Bash version 4.2          $line = #!/bin/bash