Re: encapsulating directory operations

Tim Rentsch <tr.17687@z991.linuxsc.com> writes:

Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:

Richard Harnden <richard.harnden@gmail.invalid> writes:

On 22/05/2025 23:32, Keith Thompson wrote:

[...]

In one of your library's headers:
extern const char ESCAPE;
In the corresponding *.c file:
const char ESCAPE = ('z' - 'a' == 25 ? '\x1b' : '\x27');
Change the name if you prefer.

>
Wouldn't that be a reserved identifier?

>
Yes, it would.  Good catch.
>
(Identifiers starting with E followed by either a digit or an uppercase
letter are reserved;  they could be defined as macros in <errno.h>.)

>
They are reserved only as macros, and only if <errno.h> has
been #include'd.
>
For this particular use, it's easy to make the definition work,
simply by adding
>
    #undef ESCAPE
>
before the declaration in the header file, and before the
definition in the source file (assuming of course that if
there are any #include <errno.h> they precede the #undef's).

It would be even easier to pick a different name.

If I had a time machine and sufficient influence, I might make all
the errno macros start with something more distinct, like E_ or ERR.
But I don't.

--
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
void Void(void) { Void(); } /* The recursive call of the void */