#!/usr/bin/env ruby
# fep.rb --
# simple general purpose front end for line-oriented command.
#
# Copyright (C) 1998-2006 by Takaaki Tateishi <ttate@ttsky.net>
#
# USAGE:
#  do 'fep -h'
#


# opts.rb --
#   parse the options
#
# Copyright (C) 1999 by Takaaki Tateishi <ttate@jaist.ac.jp>
# Time-stamp: <1999-03-21 23:08:38 ttate>
#
# Example:
# 1) $ARGV = ["-b","a","-a","arg1","-h","arg2","arg3"] 
#    opts = OPTS.new($ARGV,{'-a' => 1, '-h' => 0, '-b' => 1})
#    opts['-a'] ==> ["arg1"]
#    opts['-h'] ==> true
#    opts['-b'] ==> ["a"]
#    opts[0] ==> "arg2"
#    opts[1] ==> "arg3"
#
# 2) $ARGV = ["-a","-b","-c","cmd","-p","1","10","arg"]
#    opts = OPTS.new($ARGV,{'-a'=>0, '-c'=>1, '-p'=>2})
#    opts['-a'] ==> true
#    opts['-c'] ==> ["cmd"]
#    opts['-p'] ==> ["1","2"]
#    opts[0] ==> "-b"
#    opts[1] ==> "arg"

class OPTS
  attr_reader :opts, :args

  def initialize(argv=ARGV,opts={})
    @opts = {}
    @args = []
    parse(argv,opts)
  end

  def OPTS.parse(argv=ARGV,opts={})
    OPT.new(argv,opts)
  end

  def [](key)
    case key
    when Integer
      @args[key]
    when String
      @opts[key]
    else
      raise(TypeError,"key must be a integer or string")
    end
  end

  def []=(key,val)
    case key
    when Integer
      @args[key] = val
    when String
      @opts[key] = val
    else
      raise(TypeError,"key must be a integer or string")
    end
  end

  def parse(argv,opts={})
    args = argv.clone
    while( args[0] )
      case (val = opts[args[0]])
      when Integer
	if( val > 0 )
	  key = args[0]
	  args.shift
	  @opts[key] = []
	  for i in 1 .. val
	    @opts[key].push(args[0])
	    args.shift
	  end
	else
	  @opts[args[0]] = true
	  args.shift
	end
      else
	@args.push(args[0])
	args.shift
      end
    end
  end
  private :parse
end


################################################################
print <<MSG
#{$0} --
simple general purpose front end for line-oriented command.
Copyright (C) 1998-2000 by Takaaki Tateishi <ttate@jaist.ac.jp>

MSG

begin
  require "readline"
rescue LoadError
  $stderr.print("can't load readline module.\n",
		"please get and install it.\n")
  eixt(1)
end

$opts = OPTS.new(ARGV,{'-L'=>0, '-l'=>1, '-i'=>1, '-o'=>1, '-h'=>0})

if( $opts['-h'] )
  $stdout.print <<MSG
USAGE:
#{File.basename($0)} [-h] [-L] [-i <log-file>] [-o <log-file>] [-l <log-file>] <command>
-h:                this help
-i <log-file>:     records inputs into <log-file>
-o <log-file>:     records outputs of <command> into <log-file>
-l <log-file>:     same as '-i' and '-o'
MSG
  exit(0)
end

if( $opts[0] )
  CMD = $opts.args.join(" ")
else
  $stderr.print("you must specify a program and its arguments.\n")
  exit(1)
end

$USE_GETS = $opts['-L']
$ILOG_FILE_NAME = $opts['-i'][0] if $opts['-i']
$OLOG_FILE_NAME = $opts['-o'][0] if $opts['-o']
$LOG_FILE_NAME = $opts['-l'][0]  if $opts['-l']
$USE_OLOG = ($LOG_FILE_NAME || $OLOG_FILE_NAME)

def child_proc(cmd, ioin, ioout)
  STDOUT.reopen(ioout) if ioout
  STDIN.reopen(ioin) if ioin
  begin
    exec(cmd)
  rescue
    $stderr.print("can't execute '#{cmd}'.\n")
  ensure
    $pout2.close if $pout2
    $pin1.close if $pin1
  end
end

if( $LOG_FILE_NAME )
  begin
    $LOG_FILE = File.open($LOG_FILE_NAME,"w")
  rescue
    $stderr.print("can't open the file '#{$LOG_FILE_NAME}'.\n")
    exit(1)
  end
else
  $LOG_FILE = nil
end

if( $ILOG_FILE_NAME )
  begin
    $ILOG_FILE = File.open($ILOG_FILE_NAME,"w")
  rescue
    $stderr.print("can't open the file '#{$ILOG_FILE_NAME}'.\n")
    exit(1)
  end
else
  $ILOG_FILE = nil
end

if( $OLOG_FILE_NAME )
  begin
    $OLOG_FILE = File.open($OLOG_FILE_NAME,"w")
  rescue
    $stderr.print("can't open the file '#{$OLOG_FILE_NAME}'.\n")
    exit(1)
  end
else
  $OLOG_FILE = nil
end


$pin1,$pout1 = IO::pipe
$pin2,$pout2 = IO::pipe if $USE_OLOG

$pid = Process.fork{
  $pout1.close
  $pin2.close if $pin2
  $ILOG_FILE.close if $ILOG_FILE
  $OLOG_FILE.close if $OLOG_FILE
  $LOG_FILE.close if $LOG_FILE
  child_proc(CMD,$pin1,$pout2)
  exit(1)
}

$pin1.close
$pout1.sync = true

if( $USE_OLOG )
  Thread.new{
    if( $USE_GETS )
      while(str = $pin2.gets)
	$stdout.print(str)
	$LOG_FILE.print(str) if $LOG_FILE
	$OLOG_FILE.print(str) if $OLOG_FILE
      end
    else
      while(str = $pin2.read(1))
	$stdout.print(str)
	$LOG_FILE.print(str) if $LOG_FILE
	$OLOG_FILE.print(str) if $OLOG_FILE
      end
    end
    $pin2.close if $pin2
    $OLOG_FILE.close if $OLOG_FILE
  }
end

begin
  while( line = Readline.readline(" \b", true) )
    $pout1.print(line,"\n")
    $LOG_FILE.print(line,"\n") if $LOG_FILE
    $ILOG_FILE.print(line,"\n") if $ILOG_FILE
  end
ensure
  $pout1.close
  $LOG_FILE.close if $LOG_FILE
  $ILOG_FILE.close if $ILOG_FILE
end