On Fri, 15 Oct 2010 18:14:13 +0000, Grant Edwards wrote: > On 2010-10-15, Martin Gregorie <mar...@address-in-sig.invalid> wrote: >> On Fri, 15 Oct 2010 17:02:07 +0000, Grant Edwards wrote: >> >>> On 2010-10-15, Steven D'Aprano <st...@remove-this-cybersource.com.au> >>> wrote: >>> >>>> In the Unix world, which includes OS X, text tools tend to have >>>> difficulty with tabs. Or try naming a file with a newline or carriage >>>> return in the file name, or a NULL byte. >>> >>> How do you create a file with a name that contains a NULL byte? >> >> Use a language or program that doesn't use null-terminated strings. >> >> Its quite easy in many BASICs, which often delimit strings by >> preceeding it with a with a byte count, and you hit Ctrl-SPACE by >> accident.... > > I don't see what the in-program string representation has to do with it. > The Unix system calls that create files only accept NULL terminated > strings for the path parameter. > Well, obviously you can't have null in a filename if the program is using null-terminated strings.
> Are you saying that there are BASIC implementations for Unix that create > Unix files by directly accessing the disk rather than using the Unix > system calls? > I'm saying that the only BASIC implementations I've looked at the guts of have used count-delimited strings. None were on *nixen but its a safe bet that if they were ported to a UNIX they'd retain their count-delimited nature. Another language that will certainly do this is COBOL, which only uses fixed length, and therefore undelimited, strings. The point I'm making is that in both fixed length and counted string representations you can put any character value at all into the string unless whatever mechanism you're using to read in the values recognises something, i.e. TAB, CR, LF, CRLF as a delimiter, and even then the program can generate a string containing arbitrary gibberish. If you then use the string as a file name you can end up with a file that can't be accessed or deleted if the name flouts the OS's file naming conventions. I've done it in the past with BASIC programs and finger trouble under FLEX09 and CP/M. In both cases I had to use a disk editor to fix the file name before the file could be deleted or accessed. -- martin@ | Martin Gregorie gregorie. | Essex, UK org | -- http://mail.python.org/mailman/listinfo/python-list
