ipcalc: more correct checking for proper number of arguments

function                                             old     new   delta
ipcalc_main                                          581     569     -12

Signed-off-by: Steve Bennett <steveb@workware.net.au>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 12 insertions, 11 deletions

diff --git a/networking/ipcalc.c b/networking/ipcalc.c
index 78558495e..17b216354 100644
--- a/networking/ipcalc.c
+++ b/networking/ipcalc.c
@@ -63,13 +63,13 @@ int get_prefix(unsigned long netmask);
 
 #if ENABLE_FEATURE_IPCALC_LONG_OPTIONS
         static const char ipcalc_longopts[] ALIGN1 =
-                "netmask\0"   No_argument "m"
-                "broadcast\0" No_argument "b"
-                "network\0"   No_argument "n"
+                "netmask\0"   No_argument "m" // netmask from IP (assuming complete class A, B, or C network)
+                "broadcast\0" No_argument "b" // broadcast from IP [netmask]
+                "network\0"   No_argument "n" // network from IP [netmask]
 # if ENABLE_FEATURE_IPCALC_FANCY
-                "prefix\0"    No_argument "p"
-                "hostname\0"  No_argument "h"
-                "silent\0"    No_argument "s"
+                "prefix\0"    No_argument "p" // prefix from IP[/prefix] [netmask]
+                "hostname\0"  No_argument "h" // hostname from IP
+                "silent\0"    No_argument "s" // don’t ever display error messages
 # endif
                 ;
 #endif
@@ -92,15 +92,16 @@ int ipcalc_main(int argc UNUSED_PARAM, char **argv)
 #if ENABLE_FEATURE_IPCALC_LONG_OPTIONS
         applet_long_options = ipcalc_longopts;
 #endif
+        opt_complementary = "-1:?2"; /* minimum 1 arg, maximum 2 args */
         opt = getopt32(argv, "mbn" IF_FEATURE_IPCALC_FANCY("phs"));
         argv += optind;
         if (opt & SILENT)
                 logmode = LOGMODE_NONE; /* suppress error_msg() output */
-        if (opt & (BROADCAST | NETWORK | NETPREFIX)) {
-                if (!argv[0] || !argv[1] || argv[2])
-                        bb_show_usage();
-        } else {
-                if (!argv[0] || argv[1])
+        opt &= ~SILENT;
+        if (!(opt & (BROADCAST | NETWORK | NETPREFIX))) {
+                /* if no options at all or
+                 * (no broadcast,network,prefix) and (two args)... */
+                if (!opt || argv[1])
                         bb_show_usage();
         }