Question about toupper and tolower

[Hal Perkins]

You can't just turn on or off the high-order bit on any character to
convert between upper and lower case.  You still need to test that the
character you are converting is really a letter, and not a digit or
punctuation mark that should not be changed by toupper and tolower.


Hal Perkins                         UUCP: {decvax|vax135|...}!cornell!hal
Cornell Computer Science            ARPA: hal at cornell  BITNET: hal at crnlcs