Extract coseismic displacements from a GLOBK/GLORG print file
  
  Requirements: Input file GLOBK print file must contain baselines 
                prt_opt/org_opt BLEN
  
  USAGE :    sh_eq   <options>. 
  
  EXAMPLES:  
  sh_eq  -f izmit99.org -eq GPS GIZ  
  
=+=+=+=+=+=+=+=+=+=+=+=+=+ OPTIONS +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
 -f[file]        list     : globk prt files MUST have this.
  
 -eq                      : PRE/POST seismic site name extensions you require the offsets between 
                            (time ordered) MUST have this 
 
  All baselines matching the eq extensions will be extracted and printed to file(s) 
      eq_disp.[list].vel and eq_disp.[list].out 
  To get the positions stations, whether affected by the earthquake or not, also
  extracted, and printed to file          , use the following:
  
 -pos                     : extract ALL station positions 
  
 -postseismic             : extract stations with earthquake name extension only 
  
 -preseismic              : extract stations without earthquake name extension only