Add logic for erasing wsjtx_rx.log.

git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@2697 ab8295b8-cf94-4d9e-aec4-7959e3be5d79

lib/decoder.f90

@@ -1,4 +1,4 @@
-subroutine decoder(ntrSeconds,c0)
+subroutine decoder(ntrSeconds,nRxLog,c0)
 
 ! Decoder for JT9.  Can run stand-alone, reading data from *.wav files;
 ! or as the back end of wsjt-x, with data placed in a shared memory region.
@@ -63,6 +63,10 @@ subroutine decoder(ntrSeconds,c0)
      open(14,file='wsjtx_rx.log',status='unknown',position='append')
      first=.false.
   endif
+  if(iand(nRxLog,2).ne.0) rewind 14
+  if(iand(nRxLog,1).ne.0) then
+! Write date and time to lu 14     
+  endif
   write(14,1010) nutc,nsync,nsnr,xdt,1000.0+fpk,width,msg
   call flush(14)