import os, re

def cfgsummary(cfgfile, freq):
    """
    Essentially translates avgsep < cfgfile's output into a python structure.
    """
    avgsep = os.popen('/users/rreid/bin/avgsep < ' + cfgfile)
    summary = {}
    for lin in avgsep:
        if re.search('^sqrt', lin):
            nominalscale = 1000.0 * float(lin.split()[3])
            nominalscale *= 2.6682231283185 # pi / sqrt(2ln2)
            summary['nominalscale'] = nominalscale
        elif re.search('^Shortest baseline:', lin):
            summary['shortestbll'] = 1000.0 * float(lin.split()[2])
        elif re.search('^Longest baseline:', lin):
            summary['longestbll'] = 1000.0 * float(lin.split()[2])
        elif re.search('Nominal resolution acc. to rmssep:.*" at 300 GHz',
                       lin):
            summary['fwhm'] = float(re.search('rmssep:\s+([^"]+)"',
                                              lin).groups()[0]) * 300.0 / freq
            break
    avgsep.close()
    return summary