Fix the easy warnings:

1) Avoid shadowing index.
2) Constness.
3) Missing prototype for ifcmd.
4) Missing include of string.h.
5) Avoid shadowing error function.
6) ANSI definition for main.

usr.bin/systat/convtbl.c

@@ -55,24 +55,24 @@ get_tbl_ptr(const u_long size, const u_int scale)
 {
 	struct	convtbl *tbl_ptr = NULL;
 	u_long	tmp = 0;
-	u_int	index = scale;
+	u_int	idx = scale;
 
 	/* If our index is out of range, default to auto-scaling. */
-	if (index > SC_AUTO)
-		index = SC_AUTO;
+	if (idx > SC_AUTO)
+		idx = SC_AUTO;
 
-	if (index == SC_AUTO)
+	if (idx == SC_AUTO)
 		/*
 		 * Simple but elegant algorithm.  Count how many times
 		 * we can shift our size value right by a factor of ten,
 		 * incrementing an index each time.  We then use the
 		 * index as the array index into the conversion table.
 		 */
-		for (tmp = size, index = SC_KILOBYTE;
-		     tmp >= MEGA && index <= SC_GIGABYTE;
-		     tmp >>= 10, index++);
+		for (tmp = size, idx = SC_KILOBYTE;
+		     tmp >= MEGA && idx <= SC_GIGABYTE;
+		     tmp >>= 10, idx++);
 
-	tbl_ptr = &convtbl[index];
+	tbl_ptr = &convtbl[idx];
 	return tbl_ptr;
 }
 
@@ -87,7 +87,7 @@ convert(const u_long size, const u_int scale)
 
 }
 
-char *
+const char *
 get_string(const u_long size, const u_int scale)
 {
 	struct	convtbl *tp = NULL;

usr.bin/systat/convtbl.h

@@ -55,13 +55,13 @@
 struct convtbl {
 	u_int	 mul;
 	u_int	 scale;
-	char	*str;
+	const char	*str;
 };
 
 extern	struct convtbl convtbl[];
 
 extern	double 	 convert(const u_long, const u_int);
-extern	char	*get_string(const u_long, const u_int);
+extern	const char	*get_string(const u_long, const u_int);
 
 #endif		/* ! _CONVTBL_H_ */
 /*

usr.bin/systat/extern.h

@@ -108,6 +108,7 @@ void	 fetchpigs(void);
 void	 fetchswap(void);
 void	 fetchtcp(void);
 void	 getsysctl(const char *, void *, size_t);
+int	 ifcmd(const char *cmd, const char *args);
 int	 initicmp(void);
 int	 initicmp6(void);
 int	 initifstat(void);

usr.bin/systat/ifcmds.c

@@ -39,6 +39,7 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <unistd.h>
 #include <float.h>
 #include <err.h>
@@ -55,7 +56,7 @@ static	int selectscale(const char *);
 int
 ifcmd(const char *cmd, const char *args)
 {
-	if (prefix((char *)cmd, (char *)"scale")) {
+	if (prefix(cmd, "scale")) {
 		if (*args != '\0' && selectscale(args) != -1)
 			;
 		else {

usr.bin/systat/ifstat.c

@@ -39,6 +39,7 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <unistd.h>
 #include <float.h>
 #include <err.h>
@@ -56,12 +57,12 @@
 #define C4	60		/* 60-80 */
 #define C5	80		/* Used for label positioning. */
 
-static	int col0 = 0;
-static	int col1 = C1;
-static	int col2 = C2;
-static	int col3 = C3;
-static	int col4 = C4;
-static	int col5 = C5;
+static const int col0 = 0;
+static const int col1 = C1;
+static const int col2 = C2;
+static const int col3 = C3;
+static const int col4 = C4;
+static const int col5 = C5;
 
 
 SLIST_HEAD(, if_stat)		curlist;	
@@ -245,7 +246,6 @@ fetchifstat(void)
 	struct	timeval tv, new_tv, old_tv;
 	double	elapsed = 0.0;
 	u_int	new_inb, new_outb, old_inb, old_outb = 0;
-	u_int	error = 0;
 	u_int	we_need_to_sort_interface_list = 0;
 
 	SLIST_FOREACH(ifp, &curlist, link) {
@@ -257,8 +257,7 @@ fetchifstat(void)
 		old_outb = ifp->if_mib.ifmd_data.ifi_obytes;
 		ifp->tv_lastchanged = ifp->if_mib.ifmd_data.ifi_lastchange;
 
-		error = gettimeofday(&new_tv, (struct timezone *)0);
-		if (error) 
+		if (gettimeofday(&new_tv, (struct timezone *)0) != 0)
 			IFSTAT_ERR(2, "error getting time of day");
 		(void)getifmibdata(ifp->if_row, &ifp->if_mib);
 
@@ -364,7 +363,6 @@ static
 unsigned int
 getifnum(void)
 {
-	int	error   = 0;
 	u_int	data    = 0;
 	size_t	datalen = 0;
 	static	int name[] = { CTL_NET,
@@ -374,13 +372,8 @@ getifnum(void)
 			       IFMIB_IFCOUNT };
 
 	datalen = sizeof(data);
-	error = sysctl(name, 
-		       5,
-		       (void *)&data,
-		       (size_t *)&datalen,
-		       (void *)NULL,
-		       (size_t)0);
-	if (error)
+	if (sysctl(name, 5, (void *)&data, (size_t *)&datalen, (void *)NULL,
+	    (size_t)0) != 0)
 		IFSTAT_ERR(1, "sysctl error");
 	return data;
 }
@@ -388,7 +381,6 @@ getifnum(void)
 static void 
 getifmibdata(int row, struct ifmibdata *data)
 {
-	int	error   = 0;
 	size_t	datalen = 0;
 	static	int name[] = { CTL_NET,
 			       PF_LINK,
@@ -399,13 +391,8 @@ getifmibdata(int row, struct ifmibdata *data)
 	datalen = sizeof(*data);
 	name[4] = row;
 
-	error = sysctl(name,
-		       6,
-		       (void *)data,
-		       (size_t *)&datalen,
-		       (void *)NULL,
-		       (size_t)0);
-	if (error)
+	if (sysctl(name, 6, (void *)data, (size_t *)&datalen, (void *)NULL,
+	    (size_t)0) != 0)
 		IFSTAT_ERR(2, "sysctl error getting interface data");
 }
 

usr.bin/systat/main.c

@@ -82,9 +82,7 @@ int     use_kvm = 1;
 static	WINDOW *wload;			/* one line window for load average */
 
 int
-main(argc, argv)
-	int argc;
-	char **argv;
+main(int argc, char **argv)
 {
 	char errbuf[_POSIX2_LINE_MAX], dummy;
 	size_t	size;