OT: Trying to learn C -- some questions

[David Fleck]

On Thu, 25 Nov 2004, Tom Parquette wrote:
> I'm trying to learn ANSI C using a book circa 1994.  It is written from 
> a DOS perspective. Someone at work, who knows a little C, told me that 
> the book was "close enough".

I think they are probably wrong.


> 1) gcc complains that <conio.h> was not found.  If I comment out the 
> #include, the program compiles.  Is this a DOSism or something else?

I don't know if it's a DOSism, but it's definitely not a standard header 
file in the UNIX world.  I've never encountered it outside of Microsoft 
systems.


> 2) fprintf is described with stdprn being valid for a default printer. This 
> does not seem to be valid in, at least, the FreeBSD world.  man fprintf did 
> not really help.  I believe I have to create a stream for the print but I'm 
> not clear on how to do it.

Sorry, not sure about this, but again, it sounds like a DOS (or MS) 
specific implementation.


> 3) gets() is used in a number of places.  Using this gets me:
> /var/tmp//cciWrf9n.o(.text+0x20d): In function `get_data':
> : warning: warning: this program uses gets(), which is unsafe.

'gets()' will still work, but its use isn't advised.  If you're just using 
it in test programs, though, it's not a big deal.


> 4) A couple of the home work assignments use getch().  I figured out from the 
> getch man page that I needed "#include <curses.h>" but that changes the 
> errors to:
> /var/tmp//cc1GEzyG.o(.text+0x6a): In function `main':
> : undefined reference to `stdscr'
> /var/tmp//cc1GEzyG.o(.text+0x6f): In function `main':
> : undefined reference to `wgetch'
> I do not know what header file I should be including.
> Or is there something else I'm not understanding?

I think the real problem hear is that the getch() the example is 
referencing is actually a function found in conio.h.  The getch() in 
curses probably isn't the one you want anyway.
(Ref.: http://lists.apple.com/archives/mpw-dev/2001/Aug/msg00182.html)

--
David Fleck
david.fleck at mchsi.com