'Multiple SAM files may each have headers. Since the headers should all be the same, remove
the headers from files 1-n, keeping them in the first file only'

def merge(split_files, output_file):

    cmd = ('mv    %s    %s' % (split_files[0], output_file))
    result = os.system(cmd)
    if (result != 0):
        raise Exception(('Result    %s    from    %s' % (result, cmd)))
    if (len(split_files) > 1):
        cmd = ('egrep    -v    -h    "^@"    %s    >>    %s' % ('    '.join(split_files[1:]), output_file))
    result = os.system(cmd)
    if (result != 0):
        raise Exception(('Result    %s    from    %s' % (result, cmd)))
