pwait: Fix timeout unit parser

The timeout parser would check the first character after the number and
ignore any subsequent ones.

While here, switch to bool for booleans and fix some style nits.

MFC after:	1 week
Reviewed by:	0mp, markj
Differential Revision:	https://reviews.freebsd.org/D52612

bin/pwait/pwait.c

@@ -39,6 +39,7 @@
 #include <err.h>
 #include <errno.h>
 #include <signal.h>
+#include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -48,7 +49,6 @@
 static void
 usage(void)
 {
-
 	fprintf(stderr, "usage: pwait [-t timeout] [-ov] pid ...\n");
 	exit(EX_USAGE);
 }
@@ -61,15 +61,15 @@ main(int argc, char *argv[])
 {
 	struct itimerval itv;
 	struct kevent *e;
-	int oflag, tflag, verbose;
-	int i, kq, n, nleft, opt, status;
-	long pid;
 	char *end, *s;
 	double timeout;
+	long pid;
+	int i, kq, n, nleft, opt, status;
+	bool oflag, tflag, verbose;
 
-	oflag = 0;
-	tflag = 0;
-	verbose = 0;
+	oflag = false;
+	tflag = false;
+	verbose = false;
 	memset(&itv, 0, sizeof(itv));
 
 	while ((opt = getopt(argc, argv, "ot:v")) != -1) {
@@ -78,25 +78,31 @@ main(int argc, char *argv[])
 			oflag = 1;
 			break;
 		case 't':
-			tflag = 1;
+			tflag = true;
 			errno = 0;
 			timeout = strtod(optarg, &end);
 			if (end == optarg || errno == ERANGE || timeout < 0) {
 				errx(EX_DATAERR, "timeout value");
 			}
-			switch(*end) {
-			case 0:
+			switch (*end) {
+			case '\0':
+				break;
 			case 's':
+				end++;
 				break;
 			case 'h':
 				timeout *= 60;
 				/* FALLTHROUGH */
 			case 'm':
 				timeout *= 60;
+				end++;
 				break;
 			default:
 				errx(EX_DATAERR, "timeout unit");
 			}
+			if (*end != '\0') {
+				errx(EX_DATAERR, "timeout unit");
+			}
 			if (timeout > 100000000L) {
 				errx(EX_DATAERR, "timeout value");
 			}
@@ -106,7 +112,7 @@ main(int argc, char *argv[])
 			    (suseconds_t)(timeout * 1000000UL);
 			break;
 		case 'v':
-			verbose = 1;
+			verbose = true;
 			break;
 		default:
 			usage();
@@ -134,7 +140,7 @@ main(int argc, char *argv[])
 	for (n = 0; n < argc; n++) {
 		s = argv[n];
 		/* Undocumented Solaris compat */
-		if (!strncmp(s, "/proc/", 6)) {
+		if (strncmp(s, "/proc/", 6) == 0) {
 			s += 6;
 		}
 		errno = 0;