Module: Logaling::Command::Pager

Defined in:
lib/logaling/command/pager.rb

Overview

nex-3.com/posts/73-git-style-automatic-paging-in-ruby

Class Method Summary collapse

Class Method Details

.run ⇒ Object 



4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
 
# File 'lib/logaling/command/pager.rb', line 4

def self.run
  return if windows?
  return unless STDOUT.tty?

  read, write = IO.pipe

  unless Kernel.fork # Child process
    STDOUT.reopen(write)
    STDERR.reopen(write) if STDERR.tty?
    read.close
    write.close
    return
  end

  # Parent process, become pager
  STDIN.reopen(read)
  read.close
  write.close

  ENV['LESS'] = 'FSRX' # Don't page if the input is short enough

  # wait until we have input before we start the pager
  Kernel.select [STDIN]
  pager = ENV['PAGER'] || 'less'
  exec pager rescue exec "/bin/sh", "-c", pager
end