parse_num.c revision 35d886b67947dcb802da09306b6a85f1e9f99865 
1/*
2 * parse_num.c		- Parse the number of blocks
3 *
4 * Copyright (C) 2004,2005  Theodore Ts'o <tytso@mit.edu>
5 *
6 * %Begin-Header%
7 * This file may be redistributed under the terms of the GNU Library
8 * General Public License, version 2.
9 * %End-Header%
10 */
11
12#include "config.h"
13#include "e2p.h"
14
15#include <stdlib.h>
16
17unsigned long long parse_num_blocks2(const char *arg, int log_block_size)
18{
19	char *p;
20	unsigned long long num;
21
22	num = strtoull(arg, &p, 0);
23
24	if (p[0] && p[1])
25		return 0;
26
27	switch (*p) {		/* Using fall-through logic */
28	case 'T': case 't':
29		num <<= 10;
30		/* fallthrough */
31	case 'G': case 'g':
32		num <<= 10;
33		/* fallthrough */
34	case 'M': case 'm':
35		num <<= 10;
36		/* fallthrough */
37	case 'K': case 'k':
38		if (log_block_size < 0)
39			num <<= 10;
40		else
41			num >>= log_block_size;
42		break;
43	case 's':
44		if (log_block_size < 0)
45			num << 1;
46		else
47			num >>= (1+log_block_size);
48		break;
49	case '\0':
50		break;
51	default:
52		return 0;
53	}
54	return num;
55}
56
57unsigned long parse_num_blocks(const char *arg, int log_block_size)
58{
59	return parse_num_blocks2(arg, log_block_size);
60}
61
62#ifdef DEBUG
63#include <unistd.h>
64#include <stdio.h>
65
66main(int argc, char **argv)
67{
68	unsigned long num;
69	int log_block_size = 0;
70
71	if (argc != 2 && argc != 3) {
72		fprintf(stderr, "Usage: %s arg [log_block_size]\n", argv[0]);
73		exit(1);
74	}
75
76	if (argc == 3) {
77		char *p;
78
79		log_block_size = strtol(argv[2], &p, 0);
80		if (*p) {
81			fprintf(stderr, "Bad log_block_size: %s\n", argv[2]);
82			exit(1);
83		}
84	}
85
86	num = parse_num_blocks(argv[1], log_block_size);
87
88	printf("Parsed number: %lu\n", num);
89	exit(0);
90}
91#endif
92