[ruby-core:57934] Re: strlen and strnlen in Ruby

Edward Ocampo-Gooding <[e-mail]> wrote:
> (I’ve been dogmatically following the advice of my elders to favour
> strncpy whenever possible since it’s easy to run into security issues
> or accidentally feeding a non-null-byte-terminated string in and
> having the program crash or worse yet, use the result without
> checking.)

strncpy is wrong in many cases used since it pads with trailing zeros.
AFAIK strncpy is a historical artifact from an ancient database format.

There's also strlcpy from OpenBSD.  strlcpy is safe as far as crashes
go, but silently truncating data leads to other problems.

So memcpy is preferable for correctness, and heavily-used in Ruby
already since the length of Ruby strings is known.

I haven't taken the time to audit the existing uses of str*cpy in Ruby,
but I suspect many are for convenience and non-critical paths..