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

3 files changed, 75 insertions, 17 deletions

diff --git a/unprotbas.1 b/unprotbas.1
index 437cfaf..7fb818c 100644
--- a/unprotbas.1
+++ b/unprotbas.1
@@ -32,7 +32,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 unprotbas \- Unprotect or create LIST-protected Atari 8-bit BASIC programs
 .SH SYNOPSIS
 .sp
-unprotbas [\fB\-v\fP] [ [\fB\-f\fP] [\fB\-n\fP] [\fB\-g\fP] [\fB\-c\fP] [\fB\-r\fP | \fB\-w\fP] ] | [ [\fB\-p\fP | \fB\-pc\fP | \fB\-pv\fP] ] \fBinput\-file\fP \fBoutput\-file\fP
+unprotbas [\fB\-v\fP] [ [\fB\-f\fP] [\fB\-n\fP] [\fB\-g\fP] [\fB\-c\fP] [\fB\-r\fP | \fB\-w\fP] ] | [ [\fB\-p\fP | \fB\-pc\fP | \fB\-pv\fP] [\fB\-x\fP[\fIr|XX\fP] ] \fBinput\-file\fP \fBoutput\-file\fP
 .SH DESCRIPTION
 .sp
 \fBunprotbas\fP modifies a LIST\-protected Atari 8\-bit BASIC program,
@@ -55,10 +55,20 @@ tokenized BASIC is binary data and may confuse the terminal).
 Option bundling is not supported, use e.g. \fB\-v \-f\fP, not \fB\-vf\fP\&.
 To use filenames beginning with \fI\-\fP, write them as \fI\&./\-file\fP, or they
 will be treated as options.
+.SS General Options
 .INDENT 0.0
 .TP
+.B \fB\-\-help\fP
+Print usage message and exit.
+.TP
+.B \fB\-\-version\fP
+Print version number and exit.
+.TP
 .B \fB\-v\fP
 Verbose operation.
+.UNINDENT
+.SS Unprotection Options
+.INDENT 0.0
 .TP
 .B \fB\-f\fP
 Force the variable name table to be rebuilt, even if it looks OK.
@@ -87,19 +97,23 @@ generating new ones. See \fBVARIABLE NAMES\fP, below.
 .B \fB\-r\fP
 Read variable names from \fBvarnames.txt\fP, and use them instead of
 generating the names. See \fBVARIABLE NAMES\fP, below.
+.UNINDENT
+.SS Protection Options
+.INDENT 0.0
 .TP
 .B \fB\-p\fP, \fB\-pc\fP, \fB\-pv\fP
 LIST\-protect the program, rather than unprotecting it. \fB\-pc\fP sets
 an invalid (0) next\-line pointer on the last line of code. \fB\-pv\fP
 replaces the variable names with the Atari EOL character (\fB$9B\fP).
 \fB\-p\fP does both. None of the other options except \fB\-v\fP (verbose)
-can be used with these.
+and \fB\-x\fP can be used with these.
 .TP
-.B \fB\-\-help\fP
-Print usage message and exit.
-.TP
-.B \fB\-\-version\fP
-Print version number and exit.
+.B \fB\-xr\fP, \fB\-xXX\fP
+Character to use for variable name protection, with \fB\-p\fP or
+\fB\-pv\fP\&. \fIXX\fP is the character code in hex, e.g. \fB\-x20\fP to use
+a space. Default is \fB9b\fP (the EOL character). \fB\-xr\fP means random
+codes. Do not put a space between the \fB\-x\fP and the hex digits or \fBr\fP\&.
+This option only works if \fB\-p\fP or \fB\-pv\fP is used.
 .UNINDENT
 .SH EXIT STATUS
 .INDENT 0.0
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) {
diff --git a/unprotbas.rst b/unprotbas.rst
index 35a5069..a3f5e28 100644
--- a/unprotbas.rst
+++ b/unprotbas.rst
@@ -11,7 +11,7 @@ Unprotect or create LIST-protected Atari 8-bit BASIC programs
 SYNOPSIS
 ========
 
-unprotbas [**-v**] [ [**-f**] [**-n**] [**-g**] [**-c**] [**-r** | **-w**] ] | [ [**-p** | **-pc** | **-pv**] ] **input-file** **output-file**
+unprotbas [**-v**] [ [**-f**] [**-n**] [**-g**] [**-c**] [**-r** | **-w**] ] | [ [**-p** | **-pc** | **-pv**] [**-x**\[*r|XX*] ] **input-file** **output-file**
 
 DESCRIPTION
 ===========
@@ -39,9 +39,19 @@ Option bundling is not supported, use e.g. **-v -f**, not **-vf**.
 To use filenames beginning with *-*, write them as *./-file*, or they
 will be treated as options.
 
+General Options
+---------------
+**--help**
+  Print usage message and exit.
+
+**--version**
+  Print version number and exit.
+
 **-v**
   Verbose operation.
 
+Unprotection Options
+--------------------
 **-f**
   Force the variable name table to be rebuilt, even if it looks OK.
   This option cannot be combined with **-n**.
@@ -70,18 +80,21 @@ will be treated as options.
   Read variable names from **varnames.txt**, and use them instead of
   generating the names. See **VARIABLE NAMES**, below.
 
+Protection Options
+------------------
 **-p**, **-pc**, **-pv**
   LIST-protect the program, rather than unprotecting it. **-pc** sets
   an invalid (0) next-line pointer on the last line of code. **-pv**
   replaces the variable names with the Atari EOL character (**$9B**).
   **-p** does both. None of the other options except **-v** (verbose)
-  can be used with these.
-
-**--help**
-  Print usage message and exit.
-
-**--version**
-  Print version number and exit.
+  and **-x** can be used with these.
+
+**-xr**, **-xXX**
+  Character to use for variable name protection, with **-p** or
+  **-pv**. *XX* is the character code in hex, e.g. **-x20** to use
+  a space. Default is **9b** (the EOL character). **-xr** means random
+  codes. Do not put a space between the **-x** and the hex digits or **r**.
+  This option only works if **-p** or **-pv** is used.
 
 EXIT STATUS
 ===========