Make pifconfig respect interface arguments from the command line

pifconfig did not pay attention to any arguments give on the command
line, which should only list selected devices.  This patch revamps the
argument parsing, to behave as described in usage and man page.

Signed-off-by: David Sommerseth <davids@redhat.com>

Author: David Sommerseth

man/pifconfig.8.asciidoc

@@ -8,7 +8,7 @@ pifconfig - display information about a network interface
 
 SYNOPSIS
 --------
-pifconfig [INTERFACE]
+pifconfig [INTERFACE [INTERFACE [INTERFACE] ...]]
 
 
 DESCRIPTION
@@ -22,8 +22,8 @@ OPTIONS
 -------
 
 INTERFACE::
-Display information about only this interface. If no interface is given
-then all interfaces are displayed.
+Display information about only the listed interfaces. If no interface is given
+all interfaces are displayed.
 
 -h, --help::
 Show help message and exit.
@@ -39,4 +39,4 @@ AUTHORS
 -------
 Arnaldo Carvalho de Melo <acme@redhat.com>
 
-Man page written by Miroslav Suchý <msuchy@redhat.com>
+Man page written by Miroslav Suchý <msuchy@redhat.com>, David Sommerseth <davids@redhat.com>

pifconfig.py

@@ -15,11 +15,7 @@
 #   General Public License for more details.
 
 import getopt, ethtool, sys
-
-def usage():
-	print '''Usage:
-  pifconfig <interface>
-'''
+from optparse import OptionParser
 
 def flags2str(flags):
 	string = ""
@@ -76,23 +72,21 @@ def show_config(device):
 def main():
 	global all_devices
 
-	try:
-		opts, args = getopt.getopt(sys.argv[1:],
-					   "h",
-					   ("help",))
-	except getopt.GetoptError, err:
-		usage()
-		print str(err)
-		sys.exit(2)
+        usage="usage: %prog [interface [interface [interface] ...]]"
+        parser = OptionParser(usage=usage)
+        (opts, args) = parser.parse_args()
 
-	for o, a in opts:
-		if o in ("-h", "--help"):
-			usage()
-			return
+        if args is None or len(args) == 0:
+                sel_devs = ethtool.get_active_devices()
+        else:
+                sel_devs = args
 
-	active_devices = ethtool.get_active_devices()
-	for device in active_devices:
-		show_config(device)
+	for device in sel_devs:
+                try:
+                        show_config(device)
+                except Exception, ex:
+                        print "** ERROR ** [Device %s]: %s" % (device, str(ex))
+                        sys.exit(2)
 
 if __name__ == '__main__':
     main()