2.11BSD#431 - /usr/ingres/source/equel/runtime/IIatoi.c

   1: /*
   2: **  IIatoi()
   3: **  ASCII CHARACTER STRING TO 16-BIT INTEGER CONVERSION
   4: **
   5: **	`a' is a pointer to the character string, `i' is a
   6: **	pointer to the word which is to contain the result.
   7: **
   8: **	The return value of the function is:
   9: **		zero:	succesful conversion; `i' contains the integer
  10: **		+1:	numeric overflow; `i' is unchanged
  11: **		-1:	syntax error; `i' is unchanged
  12: **
  13: **	A valid string is of the form:
  14: **		<space>* [+-] <space>* <digit>* <space>*
  15: **
  16: **		Eric's utility routine.
  17: **
  18: */
  19: 
  20: IIatoi(a1, i)
  21: char    *a1;
  22: int *i;
  23: {
  24:     int     sign;       /* flag to indicate the sign */
  25:     register int    x;      /* holds the integer being formed */
  26:     register char   c;
  27:     register char   *a;
  28: 
  29:     a = a1;
  30:     sign = 0;
  31:     /* skip leading blanks */
  32:     while (*a == ' ')
  33:         a++;
  34:     /* check for sign */
  35:     switch (*a)
  36:     {
  37: 
  38:       case '-':
  39:         sign = -1;
  40: 
  41:       case '+':
  42:         while (*++a == ' ');
  43:     }
  44: 
  45:     /* at this point everything had better be numeric */
  46:     x = 0;
  47:     while ((c = *a) <= '9' && c >= '0')
  48:     {
  49:         if (x > 3276 || (x == 3276 && c > '7'))
  50:             return (1);     /* overflow */
  51:         x = x * 10 + c - '0';
  52:         a++;
  53:     }
  54: 
  55:     /* eaten all the numerics; better be all blanks */
  56:     while (c = *a++)
  57:         if(c != ' ')            /* syntax error */
  58:             return (-1);
  59:     *i = sign ? -x : x;
  60:     return (0);     /* successful termination */
  61: }

Defined functions