Teach the argument plumbing how to do -@ for mkfs.vfat

lib/args.c

@@ -84,6 +84,9 @@
 //     + Synonyms (switch on all)          [+abc] means -ab=-abc, -c=-abc
 //     ! More than one in group is error   [!abc] means -ab calls error_exit()
 //       primarily useful if you can switch things back off again.
+//
+//   You may use octal escapes with the high bit (127) set to use a control
+//   character as an option flag. For example, \300 would be the option -@
 
 // Notes from getopt man page
 //   - and -- cannot be arguments.
@@ -128,7 +131,7 @@ struct getoptflagstate
   unsigned excludes, requires;
 };
 
-// Use getoptflagstate to parse parse one command line option from argv
+// Use getoptflagstate to parse one command line option from argv
 static int gotflag(struct getoptflagstate *gof, struct opts *opt)
 {
   int type;
@@ -317,7 +320,7 @@ void parse_optflaglist(struct getoptflagstate *gof)
       continue;
 
     // Claim this option, loop to see what's after it.
-    } else new->c = *options;
+    } else new->c = 127&*options;
 
     options++;
   }

scripts/mkflags.c

@@ -137,6 +137,21 @@ struct flag *digest(char *string)
   return list;
 }
 
+// Parse C-style octal escape
+void octane(char *from)
+{
+  unsigned char *to = (void *)from;
+
+  while (*from) {
+    if (*from == '\\') {
+      *to = 0;
+      while (isdigit(*++from)) *to = (8**to)+*from-'0';
+      to++;
+    } else *to++ = *from++;
+  }
+  *to = 0;
+}
+
 int main(int argc, char *argv[])
 {
   char command[256], flags[1023], allflags[1024];
@@ -158,6 +173,8 @@ int main(int argc, char *argv[])
     *command = *flags = *allflags = 0;
     bit = fscanf(stdin, "%255s \"%1023[^\"]\" \"%1023[^\"]\"\n",
                     command, flags, allflags);
+    octane(flags);
+    octane(allflags);
 
     if (getenv("DEBUG"))
       fprintf(stderr, "command=%s, flags=%s, allflags=%s\n",
@@ -186,12 +203,14 @@ int main(int argc, char *argv[])
            command, command, command);
 
     while (offlist) {
-      struct flag *f = offlist->lopt;
+      char *s = (char []){0, 0, 0, 0};
-      while (f) {
+
-        printf("#undef FLAG_%s\n", f->command);
+      if (!offlist->command) s = offlist->lopt->command;
-        f = f->next;
+      else {
+        *s = *offlist->command;
+        if (127 < (unsigned char)*s) sprintf(s, "X%02X", 127&*s);
       }
-      if (offlist->command) printf("#undef FLAG_%c\n", *offlist->command);
+      printf("#undef FLAG_%s\n", s);
       offlist = offlist->next;
     }
     printf("#endif\n\n");
@@ -201,7 +220,7 @@ int main(int argc, char *argv[])
     out += strlen(out);
 
     while (aflist) {
-      char *llstr = bit>31 ? "LL" : "", *s = (char []){0, 0};
+      char *llstr = bit>31 ? "LL" : "", *s = (char []){0, 0, 0, 0};
       int enabled = 0;
 
       // Output flag macro for bare longopts
@@ -212,6 +231,7 @@ int main(int argc, char *argv[])
       // Output normal flag macro
       } else {
         *s = *aflist->command;
+        if (127 < (unsigned char)*s) sprintf(s, "X%02X", 127&*s);
         if (flist && flist->command && *aflist->command == *flist->command)
           enabled++;
       }