pro get_t0,t0_file,dir,n_start_line,wgse_to_gps_offset,wgset0,t0

; v2, 12/8/98, B. Rizk
;   retrieves the wgse t0 from the idx file of
;   the supplied test log, converts to seconds
;   and adds the offset to correct to GPS time 
;   in seconds 

; v4 3/9/4 works on a PC without grep

; v5b 11/9/4 works on checkout directories

time0='string'
openw,ol,t0_file,/get_lun
cd,dir
openr,ol_in,'idx',/get_lun
listcnt=0
halt=0
if n_start_line ne -1 then begin
  while not (eof(ol_in) or halt eq 1) do begin
    readf,ol_in,time0
    junk=strpos(time0,'START_SCENARIO')
    if junk ne -1 then halt=1
  endwhile
  print,time0
  parse=strsplit(time0,'-',/extract)
  print,'WGSE Start Time = ',parse(1)
  printf,ol,'WGSE Start Time = ',parse(1)
  time_extract,parse(1),hr,mn,sec,wgset0
endif else begin
  wgset0=0.0
endelse
print,'WGSE Start Time = ',wgset0,' seconds'
printf,ol,'WGSE Start Time = ',wgset0,' seconds'
print,'GPS/WGSE Offset = ',wgse_to_gps_offset,' seconds'
printf,ol,'GPS/WGSE Offset = ',wgse_to_gps_offset,' seconds'
t0=wgset0+wgse_to_gps_offset
print,'GPS Start Time = ',t0,' seconds'
printf,ol,'GPS Start Time = ',t0,' seconds'

close,/all
return
end