>> This is wrong.
>Mmm - how is it wrong, when you then try and provide an >example to back up my claim?
Well, as I said, if you count a single character as a fixed length buffer, then it isn't. And actually, _any_ input is stored in a keyboard buffer first, there is no way around it being buffered.
> And who said keyboard was my input and DOS was my
> operating system?
I didn't say yours was DOS. I said there is a way to do it in DOS. There is probably a way to do it in *nix if you use the ncurses lib and link with that.
>> buf = malloc( sizeof( char ) * 2 );
>Should be sizeof(char) + 1;
This is the exact same thing. Actually, it isn't. If you have a char that is more than one byte, then your example is wrong. Since it is theoreticly(sp) possible for char to be defined as something larger than 1, mine is correct. In reality, they're both correct. Mine is "safer". I actually had it as +1 first, but changed it.
As the previous poster wrote "Are you sure this compiles?", no I'm not. It's pseudocode. I rarely compile examples I type up. It is a point of refrence.
> And your use of realloc is broken
>> buf = realloc( sizeof( buf ) + 1 );
> 1. buf is a pointer, so sizeof doesn't tell you the right thing
> 2. if realloc returns NULL, you've lost your only pointer to the
> allocated memory.
Yeah, it should have been strlen(). You'd be hard pressed to make realloc fail here (assuming I used strlen()). It's possible, but you're have to be really bored to do so. In reality, you'd likely fill your keyboard buffer before ever running out of memory from a realloc failure.
>> sprintf( buf, "%c%s" buffer, buf );
> Mmm, does this fill up the whole of memory with the first key ?
> I mean, the 2nd parameter is buf, and you treat it as a string,
> but the string keeps growing because it's the same buff you're
> writing to.
Yeah. You're right here. I have those two backwards. You can only use this to append to the string. (I was thinking the other way around.
> It was my impression that fw9189 wanted a function like fgets
> which would allocate space as required. As I stated before,
> there is no standard function to do this.
Actually no one said anything about standards, which is why I replied. You can basicly mimic the fgets() behaviour, but it's ugly and has to be supported by your OS/Libs you're using. (Which is why I mentioned you can do it in DOS.
And yeah, I left a parameter off of my realloc call. It should go something like:
Again, this likely will not compile unless you have a DOS compiler. I don't, so I haven't tried it. I know you _can_ do what the original poster wants, but it is OS / Implementation dependent. It's not the best way to do it, but that, in theory, should work. I wasted a byte there with tbuf, but that's forgiveable and I don't really feel like rewriting this.
char *mykbdreader( )
char *buf=NULL, *tbuf=NULL, c;
while( !kbdhit() )
c = getc();
if( !buf )
buf = malloc( sizeof( char ) * 2 ); //or +1
//either way is correct.
//void *malloc(size_t nbytes);
tbuf = malloc( strlen( buf ) + 1 );
tbuf = c;
strcat( tbuf, buf );
free( buf );
buf = tbuf;
tbuf = NULL;