npc(1): adds null unveil

src/npc.c

@@ -20,7 +20,7 @@
 #include <stdio.h> /* fprintf(3), fputs(3), getc(3), perror(3), putc(3), stdin,
                     * stdout, EOF */
 #include <sysexits.h> /* EX_IOERR, EX_OK, EX_OSERR, EX_USAGE */
-#include <unistd.h> /* pledge(2), getopt(3) */
+#include <unistd.h> /* NULL, getopt(3), pledge(2), unveil(2) */
 
 char *program_name = "npc";
 
@@ -44,7 +44,7 @@ int main(int argc, char *argv[]) {
 	char showtab = 0; /* prints tab characters in caret notation */
 
 #ifdef __OpenBSD__
-	if (pledge("stdio", NULL) == -1) {
+	if (pledge("stdio unveil", NULL) == -1 || unveil(NULL, NULL)) {
 		perror(argv[0] == NULL ? program_name : argv[0]);
 		return EX_OSERR;
 	}