irb-pager/lib/pager.rb
Denis Knauf fbbb333c39 init
2011-09-28 14:50:32 +02:00

55 lines
1.4 KiB
Ruby

module Pager
module PagerHelper
def self.options opts = nil
opts = opts.kind_of?( Hash) ? opts.dup : {}
stdout = opts[:stdout] || opts[:out] || $stdout
stderr = opts[:stderr] || opts[:err] || $stderr
stdin = opts[:stdin] || opts[:in] || $stdin
pager = opts[:pager] || opts[:less] || $PAGER || ENV['PAGER'] || 'less'
rescuing = opts[:rescuing] || opts[:exceptions] || $PAGER_RESCUE
[stdout, stderr, stdin, pager, rescuing]
end
def self.exception_formatter exception
["#{exception.class}: #{exception.message}", exception.backtrace.collect {|c| "\tfrom #{c}" }].join "\n"
end
end
def self.pager obj = nil, opts = nil, &exe
if block_given?
stdout, stderr, stdin, pager, rescuing = PagerHelper.options( opts || obj)
pid, dupout, duperr, dupin = nil, stdout.dup, stderr.dup, stdin.dup
IO.pipe do |inrd, inwr|
begin
IO.pipe do |rd, wr|
pid = Process.fork do
stdin.reopen rd
wr.close
exec *pager
end
stdout.reopen wr
stderr.reopen wr
stdin.reopen inrd
if rescuing
begin
yield
rescue Object
stdout.puts PagerHelper.exception_formatter
end
else
yield
end
end
ensure
stdout.reopen dupout
stderr.reopen duperr
Process.wait pid
stdin.reopen dupin
end
end
else
pager( opts) { Kernel.p obj }
end
end
end