scanning/buffered_stream/reading.rb

tests/_examples/scanning/buffered_stream/reading.rb in the metorex repository.

require "stringio"

# A buffer handed to `read` is filled with what was read and answered in its
# place, so the caller keeps the one string it passed.
stream = StringIO.new "this is\nan example\n"
buffer = +""
p stream.read(4, buffer).equal?(buffer)
p buffer

stream.rewind
p stream.gets
p $_
p stream.gets(chomp: true)

stream.rewind
p stream.readlines(" ")
stream.rewind
p stream.each_line.to_a

# Truncating cuts the buffer itself.
text = +"123456789"
held = StringIO.new text
held.truncate 4
p text

# A stream reports the encoding its buffer carries.
tagged = StringIO.new(+"abc")
tagged.set_encoding Encoding::US_ASCII
p tagged.external_encoding
p tagged.string.encoding

Output:

true
"this"
"this is\n"
"this is\n"
"an example"
["this ", "is\nan ", "example\n"]
["this is\n", "an example\n"]
"1234"
#<Encoding:US-ASCII>
#<Encoding:US-ASCII>