File externals/Eagle/lib/Eagle1.0/file1.eagle artifact 52d35f557c part of check-in 4118dad0bc

###############################################################################
#
# file1.eagle --
#
# Extensible Adaptable Generalized Logic Engine (Eagle)
# Eagle File 1 Package File
#
# Copyright (c) 2007-2012 by Joe Mistachkin.  All rights reserved.
#
# See the file "license.terms" for information on usage and redistribution of
# this file, and for a DISCLAIMER OF ALL WARRANTIES.
#
# RCS: @(#) $Id: $
#
###############################################################################

#
# NOTE: Use our own namespace here because even though we do not directly
#       support namespaces ourselves, we do not want to pollute the global
#       namespace if this script actually ends up being evaluated in Tcl.
#
namespace eval ::Eagle {
  #
  # NOTE: This procedure reconfigures the specified channel to full binary
  #       mode.
  #
  proc makeBinaryChannel { channel } {
    fconfigure $channel -encoding binary -translation binary; # BINARY DATA
  }

  #
  # NOTE: This procedure reads all data from the specified binary file and
  #       returns it.
  #
  proc readFile { fileName } {
    set channel [open $fileName RDONLY]
    makeBinaryChannel $channel
    set result [read $channel]
    close $channel
    return $result
  }

  #
  # NOTE: This procedure writes all data to the specified binary file and
  #       returns an empty string.  Previous data contained in the file,
  #       if any, is lost.
  #
  proc writeFile { fileName data } {
    set channel [open $fileName {WRONLY CREAT TRUNC}]
    makeBinaryChannel $channel
    puts -nonewline $channel $data
    close $channel
    return ""
  }

  #
  # NOTE: This procedure appends data to the specified binary file and
  #       returns an empty string.  Previous data contained in the file,
  #       if any, is preserved.
  #
  proc appendFile { fileName data } {
    set channel [open $fileName {WRONLY CREAT APPEND}]
    makeBinaryChannel $channel
    puts -nonewline $channel $data
    close $channel
    return ""
  }

  #
  # NOTE: Provide the Eagle "file" package to the interpreter.
  #
  package provide Eagle.File \
    [expr {[isEagle] ? [info engine PatchLevel] : "1.0"}]
}