#!/bin/csh -f
#+
# grating -- show or select the DEIMOS grating and wavelength
#
# Purpose:
#	With no arguments, print the name of the current DEIMOS
#	grating and its wavelength. With one argument, selects the 
#	named DEIMOS grating.  With two arguments, sets the grating
#	and the grating wavelength.
#
# Usage:
#	grating [name [wavelen]]
# 
# Arguments:
#	name    = name of the grating to select
#	wavelen = wavelength [Angstroms] to set the grating to
# 
# Output:
#	- With no arguments, the name of the grating is printed
# 
# Restrictions:
# 
# Exit values:
#	 0 = normal completion
#	 1 = wrong number of arguments
#
# Example:
#
#-
# Modification history:
#	2002-Jun-06	GDW	Original version
#-----------------------------------------------------------------------

set buf = $0
set cmd = $buf:t
set usage = "Usage: $cmd"

# verify args...
if ( $#argv > 2 ) then
  printf "$usage\n"
  exit 1
endif

# grab args...
if ( $#argv >= 1 ) then
    set name = $1
    shift
endif

if ( $#argv >= 1 ) then
    set wavelen = $1
    shift
endif


if ( $?name ) then

    # move to grating...
    modify -s deimot GRATENAM="$name"
    if ( $status ) then
	printf "ERROR setting grating slider\n"
	exit $status
    endif

    # optionally tilt the appropriate grating...
    if ( $?wavelen ) then
	@ slider = `slider`
	modify -s deimot G${slider}TLTWAV ="$wavelen"
	if ( $status ) then
	    printf "ERROR setting grating tilt\n"
	    exit $status
	endif
    endif

else
    # default is to simply print grating name
    show -s deimot -terse GRATENAM
endif
exit