#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: LGPL (v2.1 or any later version) * 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; }