Generate v3bw files in a dir and named with timestamp

sbws/config.default.ini

 [paths]
 datadir = ${sbws_home}/datadir
-v3bw_fname = ${sbws_home}/v3bw.txt
+v3bw_dname = ${sbws_home}/v3bw
+v3bw_fname = ${v3bw_dname}/{}.v3bw
 started_filepath = ${sbws_home}/started_at
 log_filepath = ${sbws_home}/sbws.log
 

sbws/core/generate.py

@@ -35,6 +35,8 @@ def main(args, conf):
     if not is_initted(args.directory):
         fail_hard('Sbws isn\'t initialized.  Try sbws init')
 
+    os.makedirs(conf['paths']['v3bw_dname'], exist_ok=True)
+
     datadir = conf['paths']['datadir']
     if not os.path.isdir(datadir):
         fail_hard('%s does not exist', datadir)

sbws/lib/v3bwfile.py

@@ -9,7 +9,7 @@ from sbws import __version__
 from sbws.globals import SPEC_VERSION, BW_LINE_SIZE
 from sbws.lib.resultdump import ResultSuccess, _ResultType
 from sbws.util.filelock import FileLock
-from sbws.util.timestamp import now_isodt_str, unixts_to_isodt_str
+from sbws.util.timestamp import now_isodt_str, unixts_to_isodt_str, now_fname
 
 log = logging.getLogger(__name__)
 
@@ -395,7 +395,7 @@ class V3BwFile(object):
             bw_lines = scale_lines(bw_lines, args.scale_constant)
         header = V3BwHeader.from_results(conf, results)
         f = cls(header, bw_lines)
-        output = args.output or conf['paths']['v3bw_fname']
+        output = args.output or conf['paths']['v3bw_fname'].format(now_fname())
         f.write(output)
         return f
 

sbws/util/config.py

@@ -149,7 +149,7 @@ def _validate_paths(conf):
     sec = 'paths'
     err_tmpl = Template('$sec/$key ($val): $e')
     unvalidated_keys = [
-        'datadir', 'sbws_home', 'v3bw_fname',
+        'datadir', 'sbws_home', 'v3bw_fname', 'v3bw_dname',
         'started_filepath', 'log_filepath']
     all_valid_keys = unvalidated_keys
     allow_missing = ['sbws_home']

sbws/util/timestamp.py

@@ -47,6 +47,16 @@ def now_isodt_str():
     return dt_obj_to_isodt_str(datetime.utcnow())
 
 
+def now_fname():
+    """
+    Return now timestamp in UTC formatted as %Y%m%d_%H%M%S string for file
+    names.
+
+    :returns: now timestamp in UTC formatted as %Y%m%d_%H%M%S string
+    """
+    return datetime.utcnow().strftime("%Y%m%d_%H%M%S")
+
+
 def unixts_to_str(unixts):
     """Convert unix timestamp integer or float to string"""
     # even if it is only converting to str, ensure that input is nothing else