<div dir="ltr"><div dir="ltr">There's nothing special about the header files, including them just<br>copy-pastes forward definitions into your file. You can forward declare<br>any function, just make sure the types match up with the type the</div><div>function is defined with. </div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Wed, Sep 8, 2021 at 9:03 PM Jan Schaumann <<a href="mailto:jschauma@stevens.edu" target="_blank">jschauma@stevens.edu</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Timothy Wang <<a href="mailto:twang77@stevens.edu" target="_blank">twang77@stevens.edu</a>> wrote:<br>
<br>
> This leads me to believe that the underlying<br>
> implementation of getlogin is written in the OS<br>
> itself and C code will only have to declare the<br>
> function either through unistd.h or writing ?char *<br>
> getlogin(void);?.<br>
<br>
Any other takers?<br>
<br>
What about other functions, like, say, "printf" or<br>
"open" and "close"?<br>
<br>
Can we forward declare those ourselves, or must we<br>
include a header for them?<br>
<br>
-Jan<br>
_______________________________________________<br>
cs631apue mailing list<br>
<a href="mailto:cs631apue@lists.stevens.edu" target="_blank">cs631apue@lists.stevens.edu</a><br>
<a href="https://lists.stevens.edu/mailman/listinfo/cs631apue" rel="noreferrer" target="_blank">https://lists.stevens.edu/mailman/listinfo/cs631apue</a><br>
</blockquote></div>
</div>