strcmp(1): further error-proofing

src/dj.c

@@ -170,12 +170,6 @@ usage(char *argv0) {
 }
 
 int main(int argc, char *argv[]) {
-#ifdef __OpenBSD__
-	if (pledge("cpath rpath stdio unveil wpath", NULL) == -1) {
-		return oserr(NULL", errno);
-	}
-#endif
-
    	int align;    /* low 8b used, negative if no alignment is being done */
 	int count;    /* -1 if dj(1) runs until no more reads are possible */
 	char *fmt;    /* set to fmt_asv (default) or fmt_human (-H) */
@@ -183,6 +177,12 @@ int main(int argc, char *argv[]) {
 	bool retry;   /* false if exits on partial reads or writes */
 	struct Io io[2 /* { in, out } */];
 
+#ifdef __OpenBSD__
+	if (pledge("cpath rpath stdio unveil wpath", NULL) == -1) {
+		return oserr(NULL, errno);
+	}
+#endif
+
 	/* Set defaults. */
 	align = -1;
 	count = -1;
@@ -217,13 +217,9 @@ int main(int argc, char *argv[]) {
 						break;
 					} else {
 						int fd;
+
 #ifdef __OpenBSD__
-						char *perms = "wc";
+						if (unveil(optarg, i == 0 ? "r" : "wc") == -1) {
-
-						/* modify perms in-place to read-only */
-						if (i == 0) { perms = "r"; }
-
-						if (unveil(optarg, perms) == -1) {
 							return oserr(NULL, errno);
 						}
 #endif
@@ -267,6 +263,7 @@ int main(int argc, char *argv[]) {
 			}
 		}
 	}
+
 #ifdef __OpenBSD__
 	if (unveil(NULL, NULL) == -1) { return oserr(NULL, errno); }
 #endif

src/npc.c

@@ -39,22 +39,20 @@ usage(char *argv0) {
 }
 
 int main(int argc, char *argv[]) {
-#ifdef __OpenBSD__
-	program_name = argv[0] == NULL ? program_name : argv[0];
-
-	if (pledge("stdio", NULL) == -1) {
-		perror(program_name);
-		return EX_OSERR;
-	}
-#endif
 	int c;
 	char showend = 0; /* print a dollar sign before each newline */
 	char showtab = 0; /* prints tab characters in caret notation */
 
-	if (argc > 0) {
+#ifdef __OpenBSD__
-#ifndef __OpenBSD__
+	if (pledge("stdio", NULL) == -1) {
-		program_name = argv[0];
+		perror(argv[0] == NULL ? program_name : argv[0]);
+		return EX_OSERR;
+	}
 #endif
+
+	if (argc > 0) {
+		program_name = argv[0];
+
 		while ((c = getopt(argc, argv, "et")) != -1) {
 			switch (c){
 				case 'e': showend = 1; break;

src/scrut.c

@@ -17,6 +17,7 @@
  * along with this program. If not, see https://www.gnu.org/licenses/.
  */
 
+#include <assert.h> /* assert(3) */
 #include <stdio.h> /* fprintf(3), stderr, NULL */
 #include <stdlib.h> /* EXIT_FAILURE, EXIT_SUCCESS */
 #include <string.h> /* memset(3), strchr(3) */
@@ -29,6 +30,7 @@
 
 char *program_name = "scrut";
 #define OPTS "bcdefgkprsuwxLS"
+/* this is an array so main:sel's size can be known at compile time */
 static char opts[] = OPTS;
 
 static int
@@ -58,7 +60,10 @@ int main(int argc, char *argv[]) {
 		memset(sel, '\0', sizeof sel);
 		for (int c; (c = getopt(argc, argv, opts)) != -1;) {
 			if ((p = strchr(opts, c)) == NULL) { return usage(argv[0]); }
-			else { sel[p - opts] = c; }
+			else {
+				assert(p - opts < sizeof sel / sizeof *sel); /* bounds check */
+				sel[p - opts] = c;
+			}
 		}
 
 		/* straighten out selections; permute out nulls */
@@ -73,7 +78,7 @@ int main(int argc, char *argv[]) {
 
 	if (optind == argc) { return usage(argv[0]); }
 
-	for (argv += optind ; *argv != NULL; ++argv) {
+	for (argv += optind ; *argv != NULL; argv = &argv[1]) {
 		struct stat buf;
 
 #ifdef __OpenBSD__

src/strcmp.c

@@ -26,18 +26,22 @@
 char *program_name = "strcmp";
 
 int main(int argc, char *argv[]) {
-	program_name = argv[0] == NULL ? program_name : argv[0];
+	unsigned int i;
-	int i;
 
 #ifdef __OpenBSD__
 	if (pledge("stdio", NULL) == -1) {
-		perror(program_name);
+		perror(argv[0] == NULL ? program_name : argv[0]);
+
 		return EX_OSERR;
 	}
 #endif
 
 	if (argc < 3) {
-		(void)fprintf(stderr, "Usage: %s string string...\n", program_name);
+		(void)fprintf(
+			stderr,
+			"Usage: %s string string...\n",
+			argv[0] == NULL ? program_name : argv[0]
+		);
 
 		return EX_USAGE;
 	}