1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
|
#include <string.h>
#include <stdio.h>
/**
* htable - hash table routines
*
* A hash table is an efficient structure for looking up keys. This version
* grows with usage and allows efficient deletion.
*
* Example:
* #include <ccan/htable/htable.h>
* #include <ccan/hash/hash.h>
* #include <stdio.h>
* #include <err.h>
* #include <string.h>
*
* struct name_to_digit {
* const char *name;
* unsigned int val;
* };
*
* static struct name_to_digit map[] = {
* { "zero", 0},
* { "one", 1 },
* { "two", 2 },
* { "three", 3 },
* { "four", 4 },
* { "five", 5 },
* { "six", 6 },
* { "seven", 7 },
* { "eight", 8 },
* { "nine", 9 }
* };
*
* // Wrapper for rehash function pointer.
* static size_t rehash(const void *e, void *unused)
* {
* return hash_string(((struct name_to_digit *)e)->name);
* }
*
* // Comparison function.
* static bool streq(const void *e, void *string)
* {
* return strcmp(((struct name_to_digit *)e)->name, string) == 0;
* }
*
* // We let them add their own aliases, eg. --alias=v=5
* static void add_alias(struct htable *ht, const char *alias)
* {
* char *eq;
* struct name_to_digit *n;
*
* n = malloc(sizeof(*n));
* n->name = strdup(alias);
*
* eq = strchr(n->name, '=');
* if (!eq || ((n->val = atoi(eq+1)) == 0 && !strcmp(eq+1, "0")))
* errx(1, "Usage: --alias=<name>=<value>");
* *eq = '\0';
* htable_add(ht, hash_string(n->name), n);
* }
*
* int main(int argc, char *argv[])
* {
* struct htable *ht;
* unsigned int i;
* unsigned long val;
*
* if (argc < 2)
* errx(1, "Usage: %s [--alias=<name>=<val>]... <str>...",
* argv[0]);
*
* // Create and populate hash table.
* ht = htable_new(rehash, NULL);
* for (i = 0; i < sizeof(map)/sizeof(map[0]); i++)
* htable_add(ht, hash_string(map[i].name), &map[i]);
*
* // Add any aliases to the hash table.
* for (i = 1; i < argc; i++) {
* if (!strncmp(argv[i], "--alias=", strlen("--alias=")))
* add_alias(ht, argv[i] + strlen("--alias="));
* else
* break;
* }
*
* // Find the other args in the hash table.
* for (val = 0; i < argc; i++) {
* struct name_to_digit *n;
* n = htable_get(ht, hash_string(argv[i]),
* streq, argv[i]);
* if (!n)
* errx(1, "Invalid digit name %s", argv[i]);
* // Append it to the value we are building up.
* val *= 10;
* val += n->val;
* }
* printf("%lu\n", val);
* return 0;
* }
*
* License: GPLv2 (or later)
* Author: Rusty Russell <rusty@rustcorp.com.au>
*/
int main(int argc, char *argv[])
{
if (argc != 2)
return 1;
if (strcmp(argv[1], "depends") == 0) {
printf("ccan/compiler\n");
return 0;
}
return 1;
}
|
