SL>         Be warned...  I am a "newbie" to C.  (Please don't hurt me
 SL> too much...)
Cool... a user from my own BBS... I'll only hurt you locally.  ;->
 SL>     char *sTemp;
 SL>     int iTemp;
 SL>     printf("Enter a number: ");
 SL>     scanf("%s", sTemp);
Ooo.... so far, so bad.  sTemp doesn't point anywhere.  You need to give it 
some memory.
#define TEMP_LEN 30
char* sTemp = malloc(TEMP_LEN) * sizeof(char)); /* remember to free it 
afterwards */
Next problem: scanf.  If the user types in more characters than the array has 
room for, you'll overwrite it.  You could do the following:
scanf("%" STR(TEMP_LEN) "s", sTemp);
Where STR is:
#define _STR(x) #x
#define STR(x) _STR(x)
(A pair of defines are available in Snippets which are close to this [perhaps 
a name change] - I should have Snippets available for download, if not, bug 
me in private mail and I'll find it for ya.)
Anyway, this is getting ugly.  However, there is a reason to this madness, 
and it is a point on how to get really ugly code that works.  ;-)
Let's try two different solutions at this point.
1. Use scanf.
int main()
{
  int iTemp;
  int iScanned;
  printf("Enter a number: ");
  /* Note: you may want to fflush(stdout) if you use non-ANSI functions
   *       for reading, such as kbhit/getch[e] */
  iScanned = scanf("%d",&iTemp);
  if (iScanned != 1)
  {
   /* digits weren't scanned - was non-numeric */
  }
  else
  {
   /* digits were scanned, but there could be more after at least one digit. 
*/
  }
}
This shows the use of scanf's family's return codes.  It will return the 
number of variables read - in this case, we want 1.  Any other number (only 0 
is possible) means that fewer than all were read... meaning something 
"unexpected" happened.  In this case, it would mean that a character not 
conforming to the %d specifier was found first.
2. Parse everything manually
This is the form I generaly use because I find it easier to give proper error 
messages in complex inputs.  i.e., if I'm expecting a single letter followed 
by 1 or more digits followed by a dash followed by ... and I miss the dash, I 
will be able to tell the user what I was missing a lot easier than using 
scanf.
#define INPUT_LEN 30
int main()
{
  char input[INPUT_LEN];  /* allocate memory on stack, no need to free */
  int  value;
  char* pCurrentPos = input; /* iterator to walk through the input string */
  char* pLastPos = pCurrentPos; /* iterator for last position */
  printf("Enter a number: ");
  /* see note from #1 - fgets is ANSI */
  fgets(input, sizeof(input), stdin);
  /* remove the ending \n. */
  {
    int cr = strlen(input);
    if (input[cr] == '\n')
      input[cr] = '\0';
  }
  /* parse the string for digits, etc. */
  value = (int)strtol(pLastPos, &pCurrentPos, 10);
  /* we think we're done. */
  if (pCurrentPos == pLastPos)
  {
    /* in this case, the last strtol did not find any digits.  We
     * started with a non-digit. */
  }
  else if (*pCurrentPos != '\0')
  {
    /* in this case, we found some digits (because of the else), but
     * there are characters following the digits that were not parsed.
     * i.e., the user entered "10q" - pCurrentpos would be pointing at
     * the q. */
  }
  else
  {
    /* everything was parsed completely and correctly. */
    printf("You typed %d\n", value);
  }
  return 0;
}
  What a lot of work to do error-correction (error-protection?)!  Thus 
the reason for so many generic user-entry modules... so we don't have to 
continually do all of this... :-)
 SL>         Is there a way of doing this using a standard function, or
 SL> do I have to check for a zero (\0x30?) in sTemp if atoi returns a 0?
You could do this - the only reason for the longer solutions above is to help 
you should you want more than just a single number... :-)
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