getc in BSD (was FLEX issues)
keramida at ceid.upatras.gr
Tue Jul 4 00:25:45 UTC 2006
On 2006-07-03 20:06, Mike Meyer <mwm-keyword-freebsdhackers2.e313df at mired.org> wrote:
> In <44A9AC43.3090606 at jamesbailie.com>, James Bailie <jimmy at jamesbailie.com> typed:
> > Randall Hyde wrote:
> > > This kind of gives me the impression that "getc" is defined a bit
> > > differently under FreeBSD than other environments? Any ideas?
> > Yes. It's defined as a macro.
> Linux says that getc "may be implemented as a macro". Anything that
> needs a function should be using fgetc, not getc. But
The C99 standard (actually the latest public draft) allows
getc() to be a macro:
| §220.127.116.11 The getc function
| 1 #include <stdio.h>
| int getc(FILE *stream);
| 2 The getc function is equivalent to fgetc, except that if it is
| implemented as a macro, it may evaluate stream more than once,
| so the argument should never be an expression with side
This means one shouldn't depend on getc() being a function.
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