On Monday, 17 November 2014 at 12:49:16 UTC, Ola Fosheim Grøstad
wrote:
On Monday, 17 November 2014 at 12:36:49 UTC, Paulo Pinto wrote:
On Monday, 17 November 2014 at 11:43:45 UTC, Ola Fosheim
Grøstad wrote:
Remember that the alternative to zero-terminated strings at
that time was to have 2 string types, one with a one byte
length and one with a larger length. So I think C made the
right choice for it's time, to have a single string type
without a length.
Black hat hackers, virus and security tools vendors around the
world rejoice of that decision...
It was anything but right.
I don't think buffer overflow and string fundamentals are
closely related, if used reasonably, but I'm not surprised you
favour Pascal's solution of having two string types: one for
strings up to 255 bytes and another one for longer strings.
Anyway, here is the real reason for how C implemented strings:
«None of BCPL, B, or C supports character data strongly in the
language; each treats strings much like vectors of integers and
supplements general rules by a few conventions. In both BCPL
and B a string literal denotes the address of a static area
initialized with the characters of the string, packed into
cells. In BCPL, the first packed byte contains the number of
characters in the string; in B, there is no count and strings
are terminated by a special character, which B spelled `*e'.
This change was made partially to avoid the limitation on the
length of a string caused by holding the count in an 8- or
9-bit slot, and partly because maintaining the count seemed, in
our experience, less convenient than using a terminator.
Individual characters in a BCPL string were usually manipulated
by spreading the string out into another array, one character
per cell, and then repacking it later; B provided corresponding
routines, but people more often used other library functions
that accessed or replaced individual characters in a string.»
http://cm.bell-labs.com/cm/cs/who/dmr/chist.html
I am fully aware how UNIX designers decided to ignore the systems
programming being done in Algol variants, PL/I variants and many
other wannabe systems programming languages that came before C.
Which they are repeating again with Go.
--
Paulo
