🚀 go-pugleaf

[I predict there will be over 25 followups to Geo's article.]

In article <10285@watcgl.waterloo.edu> gswan@watcgl.waterloo.edu (Geo Swan) writes:
>Let me suggest that our original poster consider using the following macro:
>#define	strins( s1, s2 )	sprintf( s1, "%s%s", s2, s1 )

Can you guarantee that the above macro will work when s2 is longer than s1?
Example:  Let's say s1 is a pointer to an array of 80 bytes, and only the
first two bytes have any characters, the rest are null.  Let's say s2 is
a pointer to a string of 4 bytes.  As sprintf copies s2 into s1, it overwrites
the original string.  If sprintf copies until len(s1), then it will return
a pointer to an 8 byte string - s2 concatenated with s2.  If sprintf copies
until it gets to the null byte, it will never find it - s1 will get an
infinite number of copies of s2.  Or guru.

It's OK to use sprintf as long as the destination does not include any of
the sources.
-- 
Joe Smith (408)922-6220 | SMTP: JMS@F74.TYMNET.COM or jms@tymix.tymnet.com
McDonnell Douglas FSCO  | UUCP: ...!{ames,pyramid}!oliveb!tymix!tardis!jms
PO Box 49019, MS-D21    | PDP-10 support: My car's license plate is "POPJ P,"
San Jose, CA 95161-9019 | narrator.device: "I didn't say that, my Amiga did!"