unprotbas: don't allow -x without -p or -pv, group options in doc.

1 files changed, 33 insertions, 2 deletions

diff --git a/unprotbas.c b/unprotbas.c
index 37013cf..b2b3d98 100644
--- a/unprotbas.c
+++ b/unprotbas.c
@@ -3,6 +3,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <ctype.h>
+#include <time.h>
 
 /* attempt to fix a "list-protected" Atari 8-bit BASIC program.
 	we don't fully detokenize, so this won't fix truly corrupted
@@ -54,6 +55,9 @@ unsigned char badcode[] = {
 	0x16,         /* end-of-line token      */
 };
 
+/* for -p/-pv */
+int varname_char = 0x9b;
+
 /* for the -r option */
 #define MAP_FILE "varnames.txt"
 unsigned char varnames[BUFSIZE];
@@ -630,8 +634,13 @@ void scramble_vars(void) {
 		exit(2);
 	}
 
+	if(varname_char == -1) srand(time(NULL));
+
 	for(i = vnstart; i < vvstart - 1; i++)
-		data[i] = '\x9b';
+		if(varname_char == -1)
+			data[i] = (rand() >> 8) & 0xff;
+		else
+			data[i] = varname_char & 0xff;
 
 	if(verbose) {
 		i -= vnstart;
@@ -652,6 +661,8 @@ void print_help(void) {
 	fprintf(stderr, "-w: write variable names to varnames.txt\n");
 	fprintf(stderr, "-r: read variable names from varnames.txt\n");
 	fprintf(stderr, "-pc/-pv/-p: protect code/variables/both\n");
+	fprintf(stderr, "-xXX: hex code XX for variable names, with -p/-pc\n");
+	fprintf(stderr, "-xr: random variable names, with -p/-pc\n");
 	fprintf(stderr, "Use - as a filename to read from stdin and/or write to stdout\n");
 }
 
@@ -706,6 +717,7 @@ void open_output(const char *name) {
 
 void parse_args(int argc, char **argv) {
 	char *p;
+	int xopt_used = 0;
 
 	self = *argv;
 	p = strrchr(self, '/');
@@ -749,6 +761,23 @@ void parse_args(int argc, char **argv) {
 								 }
 							 }
 							 break;
+				case 'x': {
+								 xopt_used++;
+								 switch((*argv)[2]) {
+									case 'r':
+										varname_char = -1; break;
+									case 0:
+										die("-x option requires a hex number or 'r' (e.g. -x20, not -x 20)"); break;
+									default:
+										{
+											char *e;
+											varname_char = (int)strtol(&(*argv)[2], &e, 16);
+											if(*e != 0 || varname_char > 0xff)
+												die("invalid hex character for -x option (range is 0 to ff)");
+										}
+								 }
+							 }
+							 break;
 				case 0:
 							 if(!input_file)
 								 open_input(NULL);
@@ -776,8 +805,10 @@ void parse_args(int argc, char **argv) {
 	if(readmap && keepvars) die("-r and -n are mutually exclusive (maybe you want -w?)");
 	if(protect_code || protect_vars) {
 		if(checkonly || keepvars || forcevars || readmap || writemap || !keepgarbage)
-			die("-p, -pc, -pv options can't be combined with other options except -v");
+			die("-p, -pc, -pv options can't be combined with other options except -x, -v");
 	}
+	if(xopt_used && !protect_vars)
+		die("-x option requires -p or -pv");
 }
 
 int main(int argc, char **argv) {