PRO ASTROLIB;+; NAME:;       ASTROLIB; PURPOSE:;       Add the non-standard system variables used by the IDL Astronomy Library; EXPLANATION: ;       Also defines the environment variable ASTRO_DATA pointing to the ;       directory containing data files  associated with the IDL Astronomy ;       library (system dependent -- user must edit the third line in the;       program below).;; CALLING SEQUENCE:;       ASTROLIB;; INPUTS:;       None.;; OUTPUTS:;       None.;; METHOD:;       The non-standard system variables !PRIV, !TEXTUNIT, and ;       !TEXTOUT are added using DEFSYSV.;; REVISION HISTORY:;       Written, Wayne Landsman, July 1986.;       Use DEFSYSV instead of ADDSYSVAR           December 1990;       Test for system variable existence before definition    July 2001;       Assume since V55, remove VMS support  W. Landsman   Sep 2006;       Remove !Debug, comment out ASTRO_DATA definition  WL  Jan 2009 ;-  On_error,2  compile_opt idl2;  User should edit the folowing line and uncomment it to give the location of ;  ASTRO_DATA on their own system (or define it in their .cshrc or .bashrc file).     ;  setenv,'ASTRO_DATA=/export/home/ftp/pub/data/'  defsysv, '!PRIV', exist = exist      if not exist then defsysv, '!PRIV', 0  defsysv, '!TEXTUNIT', exist = exist     if not exist then  defsysv, '!TEXTUNIT', 0  defsysv, '!TEXTOUT', exist = exist      if not exist then defsysv, '!TEXTOUT', 1    message,'Astronomy Library system variables have been added',/INF  return  end