make-secnet-sites: Use argparse rather than ad-hoc parser

This is much less ridiculous now.

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

diff --git a/make-secnet-sites b/make-secnet-sites
index e344886782a2a7f68be67914c7798d71c37250e0..1e6a65bd0c3da7f97cdfa33ad23a2c5beb825252 100755 (executable)
--- a/make-secnet-sites
+++ b/make-secnet-sites
@@ -60,6 +60,7 @@ import sys
 import os
 import getopt
 import re
+import argparse
 
 import ipaddress
 
@@ -79,24 +80,30 @@ if version_info.major == 2:  # for python2
     import io
     open=lambda f,m='r': io.open(f,m,encoding='utf-8')
 
-# Are we being invoked from userv?
-service=0
-# If we are, which group does the caller want to modify?
-group=None
-
-if len(sys.argv)<2:
-       inputfile=None
-       of=sys.stdout
-else:
-       if sys.argv[1]=='-u':
-               if len(sys.argv)!=6:
+def parse_args():
+       global service
+       global inputfile
+       global header
+       global groupfiledir
+       global sitesfile
+       global group
+       global user
+       global of
+
+       ap = argparse.ArgumentParser(description='process secnet sites files')
+       ap.add_argument('--userv', '-u', action='store_true',
+                       help='userv service fragment update mode')
+       ap.add_argument('--prefix', '-P', nargs=1,
+                       help='set prefix')
+       ap.add_argument('arg',nargs=argparse.REMAINDER)
+       av = ap.parse_args()
+       #print(repr(av), file=sys.stderr)
+       service = 1 if av.userv else 0
+       if service:
+               if len(av.arg)!=4:
                        print("Wrong number of arguments")
                        sys.exit(1)
-               service=1
-               header=sys.argv[2]
-               groupfiledir=sys.argv[3]
-               sitesfile=sys.argv[4]
-               group=sys.argv[5]
+               (header, groupfiledir, sitesfile, group) = av.arg
                if "USERV_USER" not in os.environ:
                        print("Environment variable USERV_USER not found")
                        sys.exit(1)
@@ -113,16 +120,14 @@ else:
                        print("caller not in group %s"%group)
                        sys.exit(1)
        else:
-               if sys.argv[1]=='-P':
-                       prefix=sys.argv[2]
-                       sys.argv[1:3]=[]
-               if len(sys.argv)>3:
+               if len(av.arg)>3:
                        print("Too many arguments")
                        sys.exit(1)
-               inputfile=sys.argv[1]
-               of=sys.stdout
-               if len(sys.argv)>2:
-                       of=open(sys.argv[2],'w')
+               (inputfile, outputfile) = (av.arg + [None]*2)[0:2]
+               if outputfile is None: of=sys.stdout
+               else: of=open(sys.argv[2],'w')
+
+parse_args()
 
 # Classes describing possible datatypes in the configuration file