Actions
Bug #18957
closed
StringIO#printf doesn't ignore initial String value
Bug #18957: StringIO#printf doesn't ignore initial String value
Description
I've noticed that StringIO#printf diverges from IO#printf in the following way:
IO:
File.write("printf.txt", "1234567890") f = File.open("printf.txt", "w+") f.printf("%s", "abc") f.rewind f.gets # => "abc" StringIO:
io = StringIO.new("1234567890") io.printf("%s", "abc") io.rewind io.gets => "abc4567890" So File opened in a w mode "truncates" existing file content but StirngIO (by default) doesn't.
I would expect StringIO behaves in the same way.
Updated by mame (Yusuke Endoh) over 3 years ago
StringIO behaves like File.open with an r+ mode.
File.write("printf.txt", "1234567890") f = File.open("printf.txt", "r+") f.printf("%s", "abc") f.rewind p f.gets #=> "abc4567890" Is there any reason for you to expect it to be the same as w+ mode instead of r+?
Updated by andrykonchin (Andrew Konchin) over 3 years ago
Good point. I overlooked the difference between r+ and w+. Thank you for clarification.
Updated by jeremyevans0 (Jeremy Evans) over 3 years ago
- Status changed from Open to Rejected
Actions