diff --git a/vmstat.c b/vmstat.c
index f022928b..e0d3c23f 100644
--- a/vmstat.c
+++ b/vmstat.c
@@ -29,14 +29,15 @@
 #include "proc/sysinfo.h"
 #include "proc/version.h"
 
-static unsigned long dataUnit=1024;
-static char szDataUnit [16];
 #define UNIT_B        1
 #define UNIT_k        1000
 #define UNIT_K        1024
 #define UNIT_m        1000000
 #define UNIT_M        1048576
 
+static unsigned long dataUnit=UNIT_K;
+static char szDataUnit[3] = "K";
+
 #define VMSTAT        0
 #define DISKSTAT      0x00000001
 #define VMSUMSTAT     0x00000002
@@ -354,6 +355,7 @@ static void diskformat(void){
   if ((fDiskstat=fopen("/proc/diskstats", "rb"))){
     fclose(fDiskstat);
     ndisks=getdiskstat(&disks,&partitions);
+    if (!moreheaders) diskheader();
     for(k=0; k<ndisks; k++){
       if (moreheaders && ((k%height)==0)) diskheader();
       printf(format,
@@ -424,6 +426,7 @@ static void slabformat (void){
     return;
   }
 
+  if (!moreheaders) slabheader();
   nSlab = getslabinfo(&slabs);
   for(k=0; k<nSlab; k++){
     if (moreheaders && ((k%height)==0)) slabheader();
@@ -582,12 +585,10 @@ static int winhi(void) {
 ////////////////////////////////////////////////////////////////////////////
 
 int main(int argc, char *argv[]) {
-  char partition[16];
-  argc=0; /* redefined as number of integer arguments */
-  for (argv++;*argv;argv++) {
-    if ('-' ==(**argv)) {
-      switch (*(++(*argv))) {
-    
+  char *partition = NULL;
+  int c;
+
+  while((c = getopt(argc, argv, "VdafmDnp:S:s")) != EOF) switch(c) {
       case 'V':
 	display_version();
 	exit(0);
@@ -603,7 +604,7 @@ int main(int argc, char *argv[]) {
 	fork_format();
         exit(0);
       case 'm':
-        statMode |= SLABSTAT; 	
+        statMode |= SLABSTAT;
 	break;
       case 'D':
         statMode |= DISKSUMSTAT; 	
@@ -614,53 +615,40 @@ int main(int argc, char *argv[]) {
         break;
       case 'p':
         statMode |= PARTITIONSTAT;
-	if (argv[1]){
-	  char *cp = *++argv;
-	  if(!memcmp(cp,"/dev/",5)) cp += 5;
-	  snprintf(partition, sizeof partition, "%s", cp);
-	}else{
-	  fprintf(stderr, "-p requires an argument\n");
-          exit(EXIT_FAILURE);
-	}
+	partition = optarg;
+	if (memcmp(partition, "/dev/", 5) == 0) partition += 5;
         break;
       case 'S':
-	if (argv[1]){
-	      ++argv;
-	 	if (!strcmp(*argv, "k")) dataUnit=UNIT_k;
-	 	else if (!strcmp(*argv, "K")) dataUnit=UNIT_K;
-	 	else if (!strcmp(*argv, "m")) dataUnit=UNIT_m;
-	 	else if (!strcmp(*argv, "M")) dataUnit=UNIT_M;
-		else {fprintf(stderr, "-S requires k, K, m or M (default is kb)\n");
-		     exit(EXIT_FAILURE);
-		}
-		strcpy(szDataUnit, *argv);
-	 }else {fprintf(stderr, "-S requires an argument\n");
-		exit(EXIT_FAILURE);
-	 }
+	switch(optarg[0]) {
+	case 'b': case 'B': dataUnit = UNIT_B; break;
+	case 'k': dataUnit = UNIT_k; break;
+	case 'K': dataUnit = UNIT_K; break;
+	case 'm': dataUnit = UNIT_m; break;
+	case 'M': dataUnit = UNIT_M; break;
+	default:
+	  fprintf(stderr, "-S requires k, K, m or M (default is kb)\n");
+	  exit(EXIT_FAILURE);
+	}
+	szDataUnit[0] = optarg[0];
 	break;
       case 's':
-        statMode |= VMSUMSTAT; 	
+        statMode |= VMSUMSTAT;
 	break;
       default:
 	/* no other aguments defined yet. */
 	usage();
-      }
-   }else{
-      argc++;
-      switch (argc) {
-      case 1:
-        if ((sleep_time = atoi(*argv)) == 0)
-         usage();
-       num_updates = ULONG_MAX;
-       break;
-      case 2:
-        num_updates = atol(*argv);
-       break;
-      default:
-       usage();
-      } /* switch */
   }
-}
+
+  if (optind < argc) {
+    if ((sleep_time = atoi(argv[optind++])) == 0)
+         usage();
+    num_updates = ULONG_MAX;
+  }
+  if (optind < argc)
+    num_updates = atol(argv[optind++]);
+  if (optind < argc)
+     usage();
+
   if (moreheaders) {
       int tmp=winhi()-3;
       height=((tmp>0)?tmp:22);