Retrieve RA,DEC (in sexigecimal format) from a FITS header. If the cards for RA or DEC are not present, then query the user. The final RA,DEC strings are written to the local file named "wcs_radec_somehow.output".

Usage: wcs_radec_somehow 20150916T071707.1_acm_sci.fits 
arg1 - name of FITS image

%  wcs_radec_somehow 20150916T071707.1_acm_sci.fits 
12:12:33.88 -05:22:12.3

As an example where the user is queried:
%  date >a.fits  
%  wcs_radec_somehow a.fits 
Enter RA (hh:mm:ss.ss): 08:22:22.22
Enter DEC (sdd:mm:ss.s): +32:55:55.6
08:22:22.22 +32:55:55.6

% cat cat wcs_radec_somehow.output
08:22:22.22 +32:55:55.6