On Sat, 24 Jul 1999 13:35:03 -0500, Richard E. Hawkins wrote:
>
>> Well, and this one:
>>
>> >+ p->s[i] |= 0x20; /* fill dwarf bits to 32 and */
>> >+ p->s[i] &= 0x7f; /* decapitate all giants ... */
>>
>> This is efficient but random toggles many ascci chars... A bloody
>> massacre of many innocent bits...
>
>
>XOR them all and let the processor sort them out :)
You mean a toggle of all set bits of the mask, so that you can almost
be sure, that at least one non-printable or non-ASCCI will result:
Those file name picky versions of LaTeX will never run, your work will
never be printed...
Although this may be a desirable perspective for some, this is not what
I want at this moment... :)
Problematic are ascii 0-47, 58-64, 91-94, 96, >=123. Did I forget one?
Let's put hacking aside for a moment. Safer is the following method
LString& LString::toAsciiAlnum():
{
for (int i=0; i<length(); i++) {
[...]
LString.C: LString.h:
--------- ---------
p->s[i] &= MASK_RANGE; #define MASK_RANGE 0x7f /* or use
enum */
/* make sure, test result is foreseeable */
if (!isalnum(p->s[i]))
p->s[i] = REPLACER; #define REPLACER _ /* or whatever */
[...]
}
return *this;
}
filetools.C:
-----------
// Substitute chars that LaTeX or shell can't handle with safe ones
LString SpaceLess(LString const & file)
{
LString temp = file;
temp.toAsciiAlnum(); /* AHanses: if >127, subtract
** 127, 255 etc., put REPLACER
*/
return temp;
}
Magic numbers, etc. don't go into the program body, so LString.h is the
right place.
Still a bit complicated, though.
Greets,
Arnd
