Merge branch 'update-script' into 'master'

add script to update/maintain channel lists

See merge request !5

update-channel-list

+#!/usr/bin/env python3
+
+import os
+import sys
+import nds2
+
+
+HOSTPORT = os.getenv('NDSSERVER', 'nds.ligo.caltech.edu:31200').split(',')[0].split(':')
+HOST = HOSTPORT[0]
+if len(HOSTPORT) == 1:
+    PORT = 31200
+else:
+    PORT = int(HOSTPORT[1])
+CACHE_DIR = os.path.expanduser('~/.cache/ligo-channel-list')
+NDS_CHAN_LIST = os.getenv('NDS_CHAN_LIST', os.path.join(CACHE_DIR, 'nds-chan-list.txt'))
+EPICS_CHAN_LIST = os.getenv('EPICS_CHAN_LIST', os.path.join(CACHE_DIR, 'epics-chan-list.txt'))
+
+
+def main():
+    if len(sys.argv) > 1 and sys.argv[1] in ['-h', '--help']:
+        print("""Update channel file lists for use with ligo_channel_completion.
+
+Downloads the channel list from NDS and updates the NDS and EPICS
+channel list files.  Uses the server specified in the NDSSERVER
+environment variable, or 'nds.ligo.caltech.edu:31200' if not
+specified.  If the NDS_CHAN_LIST and EPICS_CHAN_LIST variables exist
+they are assumed to be the paths to files to be updated.  Otherwise
+the files are updated in the default cache locations:
+
+NDS_CHAN_LIST={}
+EPICS_CHAN_LIST={}
+
+Export these variables to your environment for bash channel
+completion.""".format(NDS_CHAN_LIST, EPICS_CHAN_LIST))
+        sys.exit()
+
+    params = nds2.parameters(HOST, PORT)
+
+    chans = nds2.find_channels(
+        channel_type_mask=nds2.channel.CHANNEL_TYPE_RAW,
+        params=params,
+    )
+
+    os.makedirs(os.path.dirname(NDS_CHAN_LIST), exist_ok=True)
+    os.makedirs(os.path.dirname(EPICS_CHAN_LIST), exist_ok=True)
+
+    f_nds = open(NDS_CHAN_LIST+'.tmp', 'w')
+    f_epics = open(EPICS_CHAN_LIST+'.tmp', 'w')
+
+    for chan in sorted(chans, key=lambda c: c.name):
+        f_nds.write(chan.name+'\n')
+        if chan.sample_rate == 16:
+            f_epics.write(chan.name+'\n')
+
+    os.rename(NDS_CHAN_LIST+'.tmp', NDS_CHAN_LIST)
+    os.rename(EPICS_CHAN_LIST+'.tmp', EPICS_CHAN_LIST)
+
+
+if __name__ == '__main__':
+    main()