Remove handrolled strcmp()'s

Favor readability over bare-metal.

cat.c

@@ -1,5 +1,6 @@
 /* See LICENSE file for copyright and license details. */
 #include <stdio.h>
+#include <string.h>
 #include <unistd.h>
 
 #include "text.h"
@@ -29,7 +30,7 @@ main(int argc, char *argv[])
 		concat(stdin, "<stdin>", stdout, "<stdout>");
 	} else {
 		for (; *argv; argc--, argv++) {
-			if ((*argv)[0] == '-' && !(*argv)[1]) {
+			if (!strcmp(*argv, "-")) {
 				*argv = "<stdin>";
 				fp = stdin;
 			} else if (!(fp = fopen(*argv, "r"))) {

cksum.c

@@ -1,6 +1,7 @@
 /* See LICENSE file for copyright and license details. */
 #include <inttypes.h>
 #include <stdio.h>
+#include <string.h>
 
 #include "util.h"
 
@@ -96,7 +97,7 @@ main(int argc, char *argv[])
 		cksum(stdin, NULL);
 	} else {
 		for (; *argv; argc--, argv++) {
-			if ((*argv)[0] == '-' && !(*argv)[1]) {
+			if (!strcmp(*argv, "-")) {
 				*argv = "<stdin>";
 				fp = stdin;
 			} else if (!(fp = fopen(*argv, "r"))) {

cmp.c

@@ -1,6 +1,7 @@
 /* See LICENSE file for copyright and license details. */
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 
 #include "util.h"
 
@@ -32,7 +33,7 @@ main(int argc, char *argv[])
 		usage();
 
 	for (n = 0; n < 2; n++) {
-		if (argv[n][0] == '-' && !argv[n][1]) {
+		if (!strcmp(argv[n], "-")) {
 			argv[n] = "<stdin>";
 			fp[n] = stdin;
 		} else {

cols.c

@@ -48,7 +48,7 @@ main(int argc, char *argv[])
 		getlines(stdin, &b);
 	} else {
 		for (; *argv; argc--, argv++) {
-			if ((*argv)[0] == '-' && !(*argv)[1]) {
+			if (!strcmp(*argv, "-")) {
 				*argv = "<stdin>";
 				fp = stdin;
 			} else if (!(fp = fopen(*argv, "r"))) {

comm.c

@@ -50,7 +50,7 @@ main(int argc, char *argv[])
 		usage();
 
 	for (i = 0; i < 2; i++) {
-		if (argv[i][0] == '-' && !argv[i][1]) {
+		if (!strcmp(argv[i], "-")) {
 			argv[i] = "<stdin>";
 			fp[i] = stdin;
 		} else if (!(fp[i] = fopen(argv[i], "r"))) {

cut.c

@@ -187,7 +187,7 @@ main(int argc, char *argv[])
 		cut(stdin, "<stdin>");
 	else {
 		for (; *argv; argc--, argv++) {
-			if ((*argv)[0] == '-' && !(*argv)[1]) {
+			if (!strcmp(*argv, "-")) {
 				*argv = "<stdin>";
 				fp = stdin;
 			} else if (!(fp = fopen(*argv, "r"))) {

expand.c

@@ -1,6 +1,7 @@
 /* See LICENSE file for copyright and license details. */
 #include <stdint.h>
 #include <stdlib.h>
+#include <string.h>
 
 #include "utf.h"
 #include "util.h"
@@ -110,7 +111,7 @@ main(int argc, char *argv[])
 		expand("<stdin>", stdin);
 	} else {
 		for (; *argv; argc--, argv++) {
-			if ((*argv)[0] == '-' && !(*argv)[1]) {
+			if (!strcmp(*argv, "-")) {
 				*argv = "<stdin>";
 				fp = stdin;
 			} else if (!(fp = fopen(*argv, "r"))) {

fold.c

@@ -95,7 +95,7 @@ main(int argc, char *argv[])
 		fold(stdin, "<stdin>");
 	} else {
 		for (; *argv; argc--, argv++) {
-			if ((*argv)[0] == '-' && !(*argv)[1]) {
+			if (!strcmp(*argv, "-")) {
 				*argv = "<stdin>";
 				fp = stdin;
 			} else if (!(fp = fopen(*argv, "r"))) {

grep.c

@@ -260,7 +260,7 @@ main(int argc, char *argv[])
 		match = grep(stdin, "<stdin>");
 	} else {
 		for (; *argv; argc--, argv++) {
-			if ((*argv)[0] == '-' && !(*argv)[1]) {
+			if (!strcmp(*argv, "-")) {
 				*argv = "<stdin>";
 				fp = stdin;
 			} else if (!(fp = fopen(*argv, "r"))) {

head.c

@@ -2,6 +2,7 @@
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 
 #include "util.h"
 
@@ -50,7 +51,7 @@ main(int argc, char *argv[])
 	} else {
 		many = argc > 1;
 		for (newline = 0; *argv; argc--, argv++) {
-			if ((*argv)[0] == '-' && !(*argv)[1]) {
+			if (!strcmp(*argv, "-")) {
 				*argv = "<stdin>";
 				fp = stdin;
 			} else if (!(fp = fopen(*argv, "r"))) {

join.c

@@ -528,7 +528,7 @@ main(int argc, char *argv[])
 		usage();
 
 	for (n = 0; n < 2; n++) {
-		if (argv[n][0] == '-' && !argv[n][1]) {
+		if (!strcmp(argv[n], "-")) {
 			argv[n] = "<stdin>";
 			fp[n] = stdin;
 		} else if (!(fp[n] = fopen(argv[n], "r"))) {

nl.c

@@ -190,7 +190,7 @@ main(int argc, char *argv[])
 	if (!argc) {
 		nl("<stdin>", stdin);
 	} else {
-		if (argv[0][0] == '-' && !argv[0][1]) {
+		if (!strcmp(argv[0], "-")) {
 			argv[0] = "<stdin>";
 			fp = stdin;
 		} else if (!(fp = fopen(argv[0], "r"))) {

paste.c

@@ -116,7 +116,7 @@ main(int argc, char *argv[])
 	dsc = ereallocarray(NULL, argc, sizeof(*dsc));
 
 	for (i = 0; i < argc; i++) {
-		if (argv[i][0] == '-' && !argv[i][1]) {
+		if (!strcmp(argv[i], "-")) {
 			argv[i] = "<stdin>";
 			dsc[i].fp = stdin;
 		} else if (!(dsc[i].fp = fopen(argv[i], "r"))) {

sed.c

@@ -1114,7 +1114,7 @@ next_file(void)
 			if (first) /* given no files, default to stdin */
 				file = stdin;
 			/* else we've used all our files, leave file = NULL */
-		} else if ((*files)[0] == '-' && !(*files)[1]) {
+		} else if (!strcmp(*files, "-")) {
 			file = stdin;
 			files++;
 		} else if (!(file = fopen(*files++, "r"))) {

sort.c

@@ -301,7 +301,7 @@ main(int argc, char *argv[])
 			getlines(stdin, &linebuf);
 		}
 	} else for (; *argv; argc--, argv++) {
-		if ((*argv)[0] == '-' && !(*argv)[1]) {
+		if (!strcmp(*argv, "-")) {
 			*argv = "<stdin>";
 			fp = stdin;
 		} else if (!(fp = fopen(*argv, "r"))) {

strings.c

@@ -2,6 +2,7 @@
 #include <limits.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 
 #include "utf.h"
 #include "util.h"
@@ -79,7 +80,7 @@ main(int argc, char *argv[])
 		strings(stdin, "<stdin>", len);
 	} else {
 		for (; *argv; argc--, argv++) {
-			if ((*argv)[0] == '-' && !(*argv)[1]) {
+			if (!strcmp(*argv, "-")) {
 				*argv = "<stdin>";
 				fp = stdin;
 			} else if (!(fp = fopen(*argv, "r"))) {

tail.c

@@ -115,7 +115,7 @@ main(int argc, char *argv[])
 		if ((many = argc > 1) && fflag)
 			usage();
 		for (newline = 0; *argv; argc--, argv++) {
-			if ((*argv)[0] == '-' && !(*argv)[1]) {
+			if (!strcmp(*argv, "-")) {
 				*argv = "<stdin>";
 				fp = stdin;
 			} else if (!(fp = fopen(*argv, "r"))) {

unexpand.c

@@ -1,6 +1,7 @@
 /* See LICENSE file for copyright and license details. */
 #include <stdint.h>
 #include <stdlib.h>
+#include <string.h>
 
 #include "utf.h"
 #include "util.h"
@@ -153,7 +154,7 @@ main(int argc, char *argv[])
 		unexpand("<stdin>", stdin);
 	} else {
 		for (; *argv; argc--, argv++) {
-			if ((*argv)[0] == '-' && !(*argv)[1]) {
+			if (!strcmp(*argv, "-")) {
 				*argv = "<stdin>";
 				fp = stdin;
 			} else if (!(fp = fopen(*argv, "r"))) {

uudecode.c

@@ -246,7 +246,7 @@ main(int argc, char *argv[])
 	if (argc > 1)
 		usage();
 
-	if (!argc || (argv[0][0] == '-' && !argv[0][1])) {
+	if (!argc || !strcmp(argv[0], "-")) {
 		fp = stdin;
 		ifname = "<stdin>";
 	} else {

uuencode.c

@@ -2,6 +2,7 @@
 #include <sys/stat.h>
 
 #include <stdio.h>
+#include <string.h>
 
 #include "util.h"
 
@@ -114,7 +115,7 @@ main(int argc, char *argv[])
 	if (!argc || argc > 2)
 		usage();
 
-	if (argc == 1 || (argv[0][0] == '-' && !argv[0][1])) {
+	if (argc == 1 || !strcmp(argv[0], "-")) {
 		if (mflag)
 			uuencodeb64(stdin, argv[0], "<stdin>");
 		else

wc.c

@@ -1,4 +1,6 @@
 /* See LICENSE file for copyright and license details. */
+#include <string.h>
+
 #include "utf.h"
 #include "util.h"
 
@@ -84,7 +86,7 @@ main(int argc, char *argv[])
 		wc(stdin, NULL);
 	} else {
 		for (many = (argc > 1); *argv; argc--, argv++) {
-			if ((*argv)[0] == '-' && !(*argv)[1]) {
+			if (!strcmp(*argv, "-")) {
 				*argv = "<stdin>";
 				fp = stdin;
 			} else if (!(fp = fopen(*argv, "r"))) {