variable $LAST_READ_LINE

$LAST_READ_LINE -> String | nil[permalink][rdoc] [added by English]

$_ の別名 

1 e
2 f
3 g
4 h
5 i
# end of a.txt

ruby -rEnglish -ne'p $LAST_READ_LINE' a.txt
#=>
"1 e\n"
"2 f\n"
"3 g\n"
"4 h\n"
"5 i\n"