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comparison libutil/shorthand.c @ 160:b86b3f8890ba

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libutil: shorthand decimal string parsing implemented
author Mychaela Falconia <falcon@freecalypso.org>
date Fri, 26 Feb 2021 21:04:11 +0000
parents libutil/decimal_str.c@2557012666ea
children
comparison
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159:2557012666ea 160:b86b3f8890ba
1 /*
2 * This module implements the function for parsing shorthand decimal strings.
3 */
4
5 #include <sys/types.h>
6 #include <ctype.h>
7 #include <stdio.h>
8 #include <string.h>
9 #include <strings.h>
10
11 parse_decimal_shorthand(arg, dest, maxdigits)
12 char *arg;
13 u_char *dest;
14 unsigned maxdigits;
15 {
16 unsigned n, ntail;
17
18 if (!*arg) {
19 fprintf(stderr,
20 "error: empty argument given for decimal string\n");
21 return(-1);
22 }
23 if (!isdigit(*arg)) {
24 fprintf(stderr,
25 "error: decimal string argument begins with a non-digit\n");
26 return(-1);
27 }
28 for (n = 0; isdigit(*arg); ) {
29 if (n >= maxdigits) {
30 toolong: fprintf(stderr,
31 "error: decimal string exceeds limit of %u digits\n",
32 maxdigits);
33 return(-1);
34 }
35 dest[n++] = *arg++ - '0';
36 }
37 if (!*arg) {
38 if (n != maxdigits) {
39 fprintf(stderr,
40 "error: %u digits required, %u digits given\n",
41 maxdigits, n);
42 return(-1);
43 }
44 return(0);
45 }
46 if (*arg++ != '-') {
47 malformed: fprintf(stderr,
48 "error: malformed shorthand decimal string argument\n");
49 return(-1);
50 }
51 ntail = strlen(arg);
52 if (n + ntail >= maxdigits)
53 goto toolong;
54 while (n < maxdigits - ntail)
55 dest[n++] = 0;
56 if (!isdigit(*arg))
57 goto malformed;
58 while (*arg) {
59 if (!isdigit(*arg))
60 goto malformed;
61 dest[n++] = *arg++ - '0';
62 }
63 return(0);
64 }