Re: [Libvir] [PATCH] Enhance virBuffer code
"Richard W.M. Jones" <rjones(a)redhat.com> wrote:
Jim Meyering wrote:
> What do you think of using this?
>
> isascii (*p) && isalnum (*p)
I'm not sure I'm qualified to say what this does on EBCDIC, but quite
likely lots of other code breaks there too anyway. This is nicely
self-documenting anyway.
As Daniel suggested, isalnum is locale-sensitive.
If there's a locale with an alphabetic byte that is outside
the logical a-zA-Z range, yet still within 0..127, then the above
expression will give a false-positive for that byte.
I've been inclined to stop worrying about EBCDIC for years, but a quick
search on the web finds that people are still stuck using it, and do
report bugs in ASCII-assuming code.
This is why autoconf goes to the trouble of doing this:
tr abcdefghijklmnopqrstuvwxyz ABCDEFGHIJKLMNOPQRSTUVWXYZ
not this:
tr a-z A-Z
to convert to upper case.