diff --git a/lib/nss.c b/lib/nss.c
index b902e5d7..503f97e6 100644
--- a/lib/nss.c
+++ b/lib/nss.c
@@ -70,14 +70,14 @@ void nss_init(const char *nsswitch_path) {
 		return;
 	}
 	while ((getline(&line, &len, nssfp)) != -1) {
-		if (line[0] == '\0' || line[0] == '#')
+		if (line[0] == '#')
 			continue;
 		if (strlen(line) < 8)
 			continue;
 		if (strncasecmp(line, "subid:", 6) != 0)
 			continue;
 		p = &line[6];
-		while ((*p) && isspace(*p))
+		while (isspace(*p))
 			p++;
 		if (*p != '\0')
 			break;
diff --git a/lib/port.c b/lib/port.c
index 3068ae9d..8a45b67e 100644
--- a/lib/port.c
+++ b/lib/port.c
@@ -243,9 +243,7 @@ static struct port *getportent (void)
 		 * week or the other two values.
 		 */
 
-		for (i = 0;
-		     ('\0' != cp[i]) && ('\0' != cp[i + 1]) && isalpha (cp[i]);
-		     i += 2) {
+		for (i = 0; isalpha(cp[i]) && ('\0' != cp[i + 1]); i += 2) {
 			switch ((cp[i] << 8) | (cp[i + 1])) {
 			case ('S' << 8) | 'u':
 				port.pt_times[j].t_days |= 01;
@@ -294,7 +292,7 @@ static struct port *getportent (void)
 		 * representing the times of day.
 		 */
 
-		for (dtime = 0; ('\0' != cp[i]) && isdigit (cp[i]); i++) {
+		for (dtime = 0; isdigit (cp[i]); i++) {
 			dtime = dtime * 10 + cp[i] - '0';
 		}
 
@@ -304,9 +302,7 @@ static struct port *getportent (void)
 		port.pt_times[j].t_start = dtime;
 		cp = cp + i + 1;
 
-		for (dtime = 0, i = 0;
-		     ('\0' != cp[i]) && isdigit (cp[i]);
-		     i++) {
+		for (dtime = 0, i = 0; isdigit (cp[i]); i++) {
 			dtime = dtime * 10 + cp[i] - '0';
 		}
 
diff --git a/libmisc/setupenv.c b/libmisc/setupenv.c
index b30dae34..b082fe0e 100644
--- a/libmisc/setupenv.c
+++ b/libmisc/setupenv.c
@@ -63,7 +63,7 @@ static void read_env_file (const char *filename)
 
 		cp = buf;
 		/* ignore whitespace and comments */
-		while (('\0' != *cp) && isspace (*cp)) {
+		while (isspace (*cp)) {
 			cp++;
 		}
 		if (('\0' == *cp) || ('#' == *cp)) {