############################################################################
#
#	File:     oldicon.icn
#
#	Subject:  Program to update the date in an Icon program header
#
#	Author:   Ralph E. Griswold
#
#	Date:     September 23, 1996
#
############################################################################
#
#   This file is in the public domain.
#
############################################################################
#
#  This program updates the date line in a standard Icon program header.
#  The old file is saved with the suffix ".bak".
#
#  The file then is brought up in the vi editor unless the -f option
#  is specified.
#
############################################################################
#
#  Requires:  system(), vi(1), UNIX
#
############################################################################
#
#  Links:  datetime, options
#
############################################################################

link datetime
link options

procedure main(args)
   local name, input, output, line, opts

   opts := options(args, "f")

   name := (args[1] | "foo")
   if (*name < 4) | (name[-4:0] ~== ".icn") then name ||:= ".icn"

   if system("cp " || name || " " || name || ".bak >/dev/null") ~= 0 then {
      if /opts["f"] then system("vi " || name)	# if file didn't exist
      exit()
      }

   input := open(name || ".bak") | stop("*** cannot open backup file")

   output := open(name, "w") | stop("*** cannot open ", name, " for writing")

   repeat {				# to provide a way out ...
      every 1 to 8 do write(output, read(input)) | break
      line := read(input) | break
      line ? {
         write(output, ="#	Date:     ", date()) | write(output, tab(0))
         }
      break
      }

   while write(output, read(input))

   close(output)

   if /opts["f"] then system("vi " || name)

end