added --hostname option

1 files changed, 44 insertions, 14 deletions

diff --git a/src/ipcalc.c b/src/ipcalc.c
index 5640d8c3..2535bb6b 100644
--- a/src/ipcalc.c
+++ b/src/ipcalc.c
@@ -3,18 +3,24 @@
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
+#include <netdb.h>
 
 typedef unsigned int int32;
 
 int main(int argc, char ** argv) {
-    int showBroadcast = 0, showNetwork = 0;
+    int showBroadcast = 0, showNetwork = 0, showHostname = 0;
+    int beSilent = 0;
     int rc;
     poptContext optCon;
     char * ipStr, * netmaskStr, * chptr;
     int32 ip, netmask, network, broadcast;
+    struct hostent * hostinfo;
+    char errBuf[250];
     struct poptOption optionsTable[] = {
 	    { "broadcast", '\0', 0, &showBroadcast, 0 },
+	    { "hostname", '\0', 0, &showHostname, 0 },
 	    { "network", '\0', 0, &showNetwork, 0 },
+	    { "silent", '\0', 0, &beSilent, 0 },
 	    { NULL, '\0', 0, 0, 0 },
     };
 
@@ -22,38 +28,47 @@ int main(int argc, char ** argv) {
     poptReadDefaultConfig(optCon, 1);
 
     if ((rc = poptGetNextOpt(optCon)) < -1) {
-	fprintf(stderr, "ipcalc: bad argument %s: %s\n", 
-		poptBadOption(optCon, POPT_BADOPTION_NOALIAS), 
-		poptStrerror(rc));
+	if (!beSilent)
+	    fprintf(stderr, "ipcalc: bad argument %s: %s\n", 
+		    poptBadOption(optCon, POPT_BADOPTION_NOALIAS), 
+		    poptStrerror(rc));
 	return 1;
     }
 
     if (!(ipStr = poptGetArg(optCon))) {
-	fprintf(stderr, "ipcalc: ip address expected\n");
+	if (!beSilent)
+	    fprintf(stderr, "ipcalc: ip address expected\n");
 	return 1;
     }
 
-    if (!(netmaskStr = poptGetArg(optCon))) {
-	fprintf(stderr, "ipcalc: netmask expected\n");
-	return 1;
+    if (showBroadcast || showNetwork) {
+	if (!(netmaskStr = poptGetArg(optCon))) {
+	    if (!beSilent)
+		fprintf(stderr, "ipcalc: netmask expected\n");
+	    return 1;
+	}
+
+	if (!inet_aton(netmaskStr, (struct in_addr *) &netmask)) {
+	    if (!beSilent)
+		fprintf(stderr, "ipcalc: bad netmask: %s\n", netmaskStr);
+	    return 1;
+	}
     }
 
     if ((chptr = poptGetArg(optCon))) {
-	fprintf(stderr, "ipcalc: unexpected argument: %s\n", chptr);
+	if (!beSilent)
+	    fprintf(stderr, "ipcalc: unexpected argument: %s\n", chptr);
 	return 1;
     }
 
     poptFreeContext(optCon);
 
     if (!inet_aton(ipStr, (struct in_addr *) &ip)) {
-	fprintf(stderr, "ipcalc: bad ip address: %s\n", ipStr);
+	if (!beSilent)
+	    fprintf(stderr, "ipcalc: bad ip address: %s\n", ipStr);
 	return 1;
     }
 
-    if (!inet_aton(netmaskStr, (struct in_addr *) &netmask)) {
-	fprintf(stderr, "ipcalc: bad netmask: %s\n", netmaskStr);
-	return 1;
-    }
 
     if (showBroadcast) {
 	broadcast = (ip & netmask) | ~netmask;
@@ -65,5 +80,20 @@ int main(int argc, char ** argv) {
 	printf("NETWORK=%s\n", inet_ntoa(*((struct in_addr *) &network)));
     }
 
+    if (showHostname) {
+	hostinfo = gethostbyaddr((char *) &ip, sizeof(ip), AF_INET);
+	if (!hostinfo) {
+	    if (!beSilent) {
+		sprintf(errBuf, "ipcalc: cannot find hostname for %s", ipStr);
+		herror(errBuf);
+	    }
+
+	    return 1;
+	}
+
+	printf("HOSTNAME=%s\n", hostinfo->h_name);
+    }
+	
+
     return 0;
 }