# StringIO#readlines(nil)

**URL:** <https://www.ruby-forum.com/t/stringio-readlines-nil/136616>\
**Category:** Development\
**Created:** [May 4, 2008, 2:59pm UTC](https://www.ruby-forum.com/t/stringio-readlines-nil/136616 "2008-05-04T14:59:15Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![Tanaka\_A](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/c67d28/32.png) [@Tanaka\_A](https://www.ruby-forum.com/u/Tanaka_A)\
**Post date:** [May 4, 2008, 2:59pm UTC](https://www.ruby-forum.com/t/stringio-readlines-nil/136616/1 "2008-05-04T14:59:15Z")

</div>

e$B0J2\<$N$h$&$Ke(B StringIO#readlines e$B$Ke(B nil e$B$rM?$($k$He(B  
TypeError  
e$B$K$J$j$^$9!#e(B

% ./ruby -rstringio -e ‘p StringIO.new(“a\nb\n”).readlines(nil)’  
-e:1:in `readlines': can't convert nil into String (TypeError) from -e:1:in`’

IO#readlines e$B$J$i!"0J2\<$N$h$&$K%U%!%$%k$N;D$jA4It$,0l9T$H$7e(B  
e$B$FF@$i$l$^$9!#e(B

% ruby -e ‘puts “a”, “b”’ | ./ruby -e ‘p STDIN.readlines(nil)’  
[“a\nb\n”]