4.3BSD - /usr/ingres/source/gutil/scompare.c

   1: # include   <useful.h>
   2: # include   <sccs.h>
   3: 
   4: SCCSID(@(#)scompare.c	8.3	1/17/85)
   5: 
   6: /*
   7: **  STRING COMPARE
   8: **
   9: **	The strings 'a_ptr' and 'b_ptr' are compared.  Blanks are
  10: **	ignored.  The first string may be no longer than 'a_len'
  11: **	bytes, and the second string may be no longer than 'b_len'
  12: **	bytes.  If either length is zero, it is taken to be very
  13: **	long.  A null byte also terminates the scan.
  14: **
  15: **	Compares are based on the ascii ordering.
  16: **
  17: **	Shorter strings are less than longer strings.
  18: **
  19: **	Return value is positive one for a > b, minus one for a < b,
  20: **	and zero for a == b.
  21: **
  22: **	Examples:
  23: **		"abc" > "ab"
  24: **		"  a bc  " == "ab  c"
  25: **		"abc" < "abd"
  26: */
  27: 
  28: scompare(a_ptr, a_len, b_ptr, b_len)
  29: char    *a_ptr;
  30: int a_len;
  31: char    *b_ptr;
  32: int b_len;
  33: {
  34:     char        *ap;
  35:     char        *bp;
  36:     register char   a;
  37:     char        b;
  38:     register int    al;
  39:     register int    bl;
  40: 
  41:     ap = a_ptr;
  42:     bp = b_ptr;
  43:     al = a_len;
  44:     if (al == 0)
  45:         al = MAXI4;
  46:     bl = b_len;
  47:     if (bl == 0)
  48:         bl = MAXI4;
  49: 
  50:     while (1)
  51:     {
  52: 
  53:         /* supress blanks in both strings */
  54:         while ((a = *ap) == ' ' && al > 0)
  55:         {
  56:             al--;
  57:             ap++;
  58:         }
  59:         if (al == 0)
  60:             a = 0;
  61:         while (*bp == ' ' && bl > 0)
  62:         {
  63:             bl--;
  64:             bp++;
  65:         }
  66:         if (bl == 0)
  67:             b = 0;
  68:         else
  69:             b = *bp;
  70: 
  71:         /* do inequality tests */
  72:         if (a < b)
  73:             return (-1);
  74:         if (a > b)
  75:             return (1);
  76:         if (a == 0)
  77:             return (0);
  78: 
  79:         /* go on to the next character */
  80:         ap++;
  81:         al--;
  82:         bp++;
  83:         bl--;
  84:     }
  85: }

Defined functions