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IO#expect
# File tmp/rubies/ruby-4.1.0-preview1/ext/pty/lib/expect.rb, line 33
def expect(pat,timeout=9999999)
buf = ''.dup
case pat
when String
e_pat = Regexp.new(Regexp.quote(pat))
when Regexp
e_pat = pat
else
raise TypeError, "unsupported pattern class: #{pat.class}"
end
@unusedBuf ||= ''
while true
if not @unusedBuf.empty?
c = @unusedBuf.slice!(0)
elsif !IO.select([self],nil,nil,timeout) or eof? then
result = nil
@unusedBuf = buf
break
else
c = getc
end
buf << c
if $expect_verbose
STDOUT.print c
STDOUT.flush
end
if mat=e_pat.match(buf) then
result = [buf,*mat.captures]
break
end
end
if block_given? then
yield result
else
return result
end
nil
end
The expect library adds instance method IO#expect, which is similar to the TCL expect extension.
To use this method, you must require expect:
require 'expect'
Reads from the IO until the given pattern matches or the timeout is over.
It returns an array with the read buffer, followed by the matches. If a block is given, the result is yielded to the block and returns nil.
When called without a block, it waits until the input that matches the given pattern is obtained from the IO or the time specified as the timeout passes. An array is returned when the pattern is obtained from the IO. The first element of the array is the entire string obtained from the IO until the pattern matches, followed by elements indicating which the pattern which matched to the anchor in the regular expression.
The optional timeout parameter defines, in seconds, the total time to wait for the pattern. If the timeout expires or eof is found, nil is returned or yielded. However, the buffer in a timeout session is kept for the next expect call. The default timeout is 9999999 seconds.