compare strings, strcmp

Conor P. Cahill cpcahil at virtech.uucp
Tue Nov 21 11:31:45 AEST 1989


In article <5139 at mnetor.UUCP>, lazer at mnetor.UUCP (Lazer Danzinger) writes:

> +This macro is "unsafe" because the macro arguments a and b are used twice,
> +hence possible side effect difficulties...

>     I see no possibility of side effects. What is unsafe is the
>     referencing of the location where a and b point to, without
>     first checking that they are not null pointers. 

wrongo.  you (the programmer) must do that before calling StrEqu.  This macro
was designed to be a replacement for using strcmp directly and therefore has
the same requirements as the strcmp function itself.  Calling
strcmp with a null pointer will result in a core dump on lots of machines
and undefined behavior on all others.

The side effects have been addressed in lots of other posts in this thread.
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