1 /*****************************************************************************
2 * RRDtool 1.1.x Copyright Tobias Oetiker, 1999
3 * This code is stolen from rateup (mrtg-2.x) by Dave Rand
4 *****************************************************************************
5 * diff calculate the difference between two very long integers available as
7 *****************************************************************************
10 * Revision 1.3 2002/04/01 18:31:22 oetiker
11 * "!" takes a higher preference than "||" this means rrd_update N:: would
12 * segfault -- Oliver Cook <ollie@uk.clara.net>
14 * Revision 1.2 2002/02/01 20:34:49 oetiker
15 * fixed version number and date/time
17 * Revision 1.1.1.1 2001/02/25 22:25:05 oetiker
20 * Revision 1.1 1998/10/08 18:21:45 oetiker
23 * Revision 1.3 1998/02/06 21:10:52 oetiker
24 * removed max define .. it is now in rrd_tool.h
26 * Revision 1.2 1997/12/07 20:38:03 oetiker
29 * Revision 1.1 1997/11/28 23:31:59 oetiker
32 *****************************************************************************/
37 rrd_diff(char *a, char *b)
39 char res[LAST_DS_LEN+1], *a1, *b1, *r1, *fix;
42 while (!(isdigit((int)*a) || *a==0))
45 while (isdigit((int)*fix))
47 *fix = 0; /* maybe there is some non digit data in the string */
48 while (!(isdigit((int)*b) || *b==0))
51 while (isdigit((int)*fix))
53 *fix = 0; /* maybe there is some non digit data in the string */
54 if(!isdigit((int)*a) || !isdigit((int)*b))
57 m = max(strlen(a),strlen(b));
58 if (m > LAST_DS_LEN) return DNAN; /* result string too short */
61 for (b1 = res;b1 <= r1; b1++) *b1 = ' ';
63 r1[1] = 0; /* Null terminate result */
66 if (a1 >= a && b1 >= b) {
67 *r1 = ((*a1 - c) - *b1) + '0';
71 *r1 = ('0' - *b1 - c) + '0';
77 if (*r1 > '9') { /* 0 - 10 */
87 for (x=0; isdigit((int)*r1) && x<m; x++,r1--) {
88 *r1 = ('9' - *r1 + c) + '0';