Jim Meyering wrote:
"Richard W.M. Jones" <rjones 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.
Another factor to consider here is that it doesn't matter if this function over-escapes, but it does matter if the function under-escapes. That is to say, it could escape every character as a %xx hex code, which would be ugly and slightly inefficient but not wrong.
Rich. -- Emerging Technologies, Red Hat - http://et.redhat.com/~rjones/ Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SL4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 03798903
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