class Shell::Filter

Any result of command execution is a Filter.

This class includes Enumerable, therefore a Filter object can use all Enumerable facilities.

Attributes

input[R]

Public Class Methods

new(sh) click to toggle source

# File lib/shell/filter.rb, line 23
def initialize(sh)
  @shell = sh         # parent shell
  @input = nil        # input filter
end

Public Instance Methods

filter1 + filter2 click to toggle source

Outputs filter1, and then filter2 using Join.new

# File lib/shell/filter.rb, line 114
def + (filter)
  Join.new(@shell, self, filter)
end

< source click to toggle source

Inputs from source, which is either a string of a file name or an IO object.

# File lib/shell/filter.rb, line 50
def < (src)
  case src
  when String
    cat = Cat.new(@shell, src)
    cat | self
  when IO
    self.input = src
    self
  else
    Shell.Fail Error::CantApplyMethod, "<", to.class
  end
end

> source click to toggle source

Outputs from source, which is either a string of a file name or an IO object.

# File lib/shell/filter.rb, line 68
def > (to)
  case to
  when String
    dst = @shell.open(to, "w")
    begin
      each(){|l| dst << l}
    ensure
      dst.close
    end
  when IO
    each(){|l| to << l}
  else
    Shell.Fail Error::CantApplyMethod, ">", to.class
  end
  self
end

>> source click to toggle source

Appends the output to source, which is either a string of a file name or an IO object.

# File lib/shell/filter.rb, line 90
def >> (to)
  begin
    Shell.cd(@shell.pwd).append(to, self)
  rescue CantApplyMethod
    Shell.Fail Error::CantApplyMethod, ">>", to.class
  end
end

each(record_separator=nil) { block } click to toggle source

Iterates a block for each line.

# File lib/shell/filter.rb, line 38
def each(rs = nil)
  rs = @shell.record_separator unless rs
  if @input
    @input.each(rs){|l| yield l}
  end
end

input=(filter) click to toggle source

# File lib/shell/filter.rb, line 30
def input=(filter)
  @input = filter
end

inspect() click to toggle source

Calls superclass method Object#inspect

# File lib/shell/filter.rb, line 130
def inspect
  if @shell.debug.kind_of?(Integer) && @shell.debug > 2
    super
  else
    to_s
  end
end

to_a() click to toggle source

# File lib/shell/filter.rb, line 118
def to_a
  ary = []
  each(){|l| ary.push l}
  ary
end

to_s() click to toggle source

# File lib/shell/filter.rb, line 124
def to_s
  str = ""
  each(){|l| str.concat l}
  str
end

| filter click to toggle source

Processes a pipeline.

# File lib/shell/filter.rb, line 102
def | (filter)
  filter.input = self
  if active?
    @shell.process_controller.start_job filter
  end
  filter
end