Prefix lengths are much more convenient, support them as an alternative to passing -m separately from -A.
* ifconfig/options.c (parse_opt): Detect prefix length, and in such a case, call parse_opt_set_netmask. Index: inetutils-2.3/ifconfig/options.c =================================================================== --- inetutils-2.3.orig/ifconfig/options.c +++ inetutils-2.3/ifconfig/options.c @@ -547,8 +547,29 @@ parse_opt (int key, char *arg, struct ar break; case 'A': /* Interface address. */ - parse_opt_set_address (ifp, arg); - break; + { + char *netlen = strchr (arg, '/'); + + if (netlen) + { + char *end, *str; + unsigned n; + struct in_addr addr; + + *netlen++ = 0; + + n = strtol (netlen, &end, 10); + if (end == netlen) + error (EXIT_FAILURE, 0, "Wrong netmask length %s", netlen); + + addr.s_addr = htonl (INADDR_BROADCAST << (32-n)); + str = strdup (inet_ntoa (addr)); + parse_opt_set_netmask (ifp, str); + } + + parse_opt_set_address (ifp, arg); + break; + } case 'm': /* Interface netmask. */ parse_opt_set_netmask (ifp, arg);