str(1): updates to use pledge(2)

src/str.c

@@ -22,7 +22,11 @@
 #include <stdio.h> /* fprintf(3) */
 #include <stdlib.h> /* size_t, EXIT_FAILURE */
 #include <string.h> /* strcmp(3) */
-#include <sysexits.h> /* EX_USAGE */
+#include <sysexits.h> /* EX_OSERR, EX_USAGE */
+
+#ifdef __OpenBSD__
+#	include <unistd.h> /* pledge(2) */
+#endif
 
 char *program_name = "str";
 
@@ -55,8 +59,16 @@ usage(char *argv0) {
 int main(int argc, char *argv[]) {
 	size_t ctype; // selected from ctypes.h; index of ctype
 	int retval; // initially fail but becomes success on the first valid char
+	program_name = argv[0] == NULL ? program_name : argv[0];
 
-	if (argc < 3) { return usage(argv[0] == NULL ? program_name : argv[0]); }
+#ifdef __OpenBSD__
+	if (pledge("stdio", NULL) == -1) {
+		perror(program_name);
+		return EX_OSERR;
+	}
+#endif
+
+	if (argc < 3) { return usage(program_name); }
 
 	for ( /* iterate ctypes */
 		ctype = 0;