In Files

  • pty/lib/expect.rb



Class/Module Index [+]



Expect library adds the IO instance method expect, which does similar act to tcl’s expect extension.

In order to use this method, you must require expect:

require 'expect'

Please see expect for usage.

Public Instance Methods

IO#expect(pattern,timeout=9999999) → Array click to toggle source
IO#expect(pattern,timeout=9999999) { |result| ... } → nil

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.

               # File pty/lib/expect.rb, line 32
def expect(pat,timeout=9999999)
  buf = ''
  case pat
  when String
    e_pat =
  when Regexp
    e_pat = pat
    raise TypeError, "unsupported pattern class: #{pat.class}"
  @unusedBuf ||= ''
  while true
    if not @unusedBuf.empty?
      c = @unusedBuf.slice!(0).chr
    elsif ![self],nil,nil,timeout) or eof? then
      result = nil
      @unusedBuf = buf
      c = getc.chr
    buf << c
    if $expect_verbose
      STDOUT.print c
    if mat=e_pat.match(buf) then
      result = [buf,*mat.to_a[1..-1]]
  if block_given? then
    yield result
    return result

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