Change port.

Makefile

@@ -9,7 +9,7 @@ TEST_SRC  = $(wildcard test/*.c)
 TEST_BINS = $(patsubst test/%,bin/%,$(patsubst %.c,%.test,$(TEST_SRC)))
 
 # CFLAGS  = -std=c99 -Ideps -Wall -Wno-unused-function -U__STRICT_ANSI__
-CFLAGS  = -ggdb -std=c99 -Ideps -Ilib -Wall -Wno-unused-function -pedantic 
+CFLAGS  = -ggdb -std=c99 -Ideps -Ilib -Wall -Wno-unused-function -pedantic -D_POSIX_C_SOURCE=200112L
 
 
 all: $(BINS) $(TEST_BINS)

src/hashtable-simple.c

@@ -0,0 +1,154 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+typedef struct hashcell_t {
+	char key[128];
+	void * value;
+	struct hashcell_t* next;
+} HASHCELL;
+
+typedef struct {
+	int capacity;
+	int size;
+	HASHCELL** data;
+} HASHTABLE;
+
+int hash_of_key(HASHTABLE* hashtable, char * key) {
+	int val=0;
+	int idx=0;
+	while (key[idx] != '\0') {
+		val ^= key[idx];
+		idx++;
+	}
+	return (val % hashtable->capacity);
+}
+
+HASHTABLE* hashtable_create(int capacity) {
+	HASHTABLE * hashtable;
+	printf("hashtable_create -- %d\n", capacity);
+
+	hashtable = malloc(sizeof(HASHTABLE));
+	if (!hashtable) return NULL;
+	memset(hashtable, 0, sizeof(HASHTABLE));
+
+	hashtable->data = malloc(capacity * sizeof(HASHCELL*));
+	if (!hashtable->data) return NULL;
+	memset(hashtable->data, 0, capacity * sizeof(HASHCELL*));
+
+	hashtable->capacity = capacity;
+	hashtable->size = 0;
+
+	printf("hashtable_create -- done\n");
+	return hashtable;
+}
+
+void hashtable_destroy(HASHTABLE* hashtable) {
+	printf("hashtable_destroy(%p) -- \n", (void*)hashtable);
+	if (!hashtable) return;
+	if (!hashtable->data) return;
+	free(hashtable->data);
+	free(hashtable);
+	printf("hashtable_destroy(%p) -- done\n", (void*)hashtable);
+}
+
+void hashtable_rehash(HASHTABLE* hashtable) {
+	return;
+}
+
+int hashtable_set(HASHTABLE* hashtable, char* key, void * value) {
+	int idx;
+	HASHCELL* cell;
+
+	printf("hashtable_set(%s, %p) -- \n", key, (void*)value);
+	// get position in hashtable
+	idx = hash_of_key(hashtable, key);
+	hashtable->size += 1;
+
+	printf("hashtable_set -- index [%d/%d]\n", idx, hashtable->capacity);
+	// search value
+	cell = hashtable->data[idx];
+	while(cell) {
+		if (strcmp(cell->key, key) == 0) { break; }
+		cell = cell->next;
+	}
+
+	if (cell) {
+		// if cell exists, then change inner value
+		printf("hashtable_set -- update value\n");
+		cell->value = value;
+	} else {
+		printf("hashtable_set -- create value\n");
+		// create cell & prepend it to the chain
+		cell = malloc(sizeof(HASHCELL));
+		if (!cell) return -1;
+		memset(cell, 0, sizeof(HASHCELL));
+
+		cell->next = hashtable->data[idx];
+		cell->value = value; 
+		strcpy(cell->key, key);
+		hashtable->data[idx] = cell;
+		printf("hashtable_set -- cell@%p{key=%s, value=%p, next=%p}\n", 
+				(void*)cell,
+				cell->key,
+				(void*)cell->value,
+				(void*)cell->next);
+	}
+	printf("hashtable_set(...) -- done\n");
+
+	return 0;
+}
+
+void * hashtable_get(HASHTABLE* hashtable, char* key) {
+	int idx;
+	HASHCELL* cell;
+	printf("hashtable_get(%p, %p) -- \n", hashtable, key);
+	idx = hash_of_key(hashtable, key);
+	printf("hashtable_get(...) -- index [%d/%d]\n", idx, hashtable->capacity);
+	cell = hashtable->data[idx];
+	while(cell) {
+		printf("hashtable_get(...) -- cell@%p{key=%s, value=%p, next=%p}\n", 
+				(void*)cell,
+				cell->key,
+				cell->value,
+				cell->next);
+		if (strcmp(cell->key, key) == 0) { break; }
+		cell = cell->next;
+	}
+	if (cell) { 
+		return cell->value;
+	} else {
+		printf("hashtable_get(...) -- cell not found\n");
+		return NULL;
+	}
+}
+
+int main(int argc, char** argv) {
+	HASHTABLE * hashtable;
+	int x=1, y=2, z=3;
+	int* value;
+
+	printf("Run !\n");
+	hashtable = hashtable_create(1000);
+	hashtable_destroy(hashtable);
+
+	hashtable = hashtable_create(100);
+	hashtable_set(hashtable, "alice", &x);
+	printf("h['alice'] <- %d\n", x);
+	hashtable_set(hashtable, "bob", &y);
+	printf("h['bob'] <- %d\n", y);
+	hashtable_set(hashtable, "charlie", &z);
+	printf("h['charlie'] <- %d\n", z);
+	hashtable_set(hashtable, "alice", &y);
+	printf("h['alice'] <- %d\n", y);
+
+	value = hashtable_get(hashtable, "alice"); 
+	printf("h['alice'] ? %d\n", *value);
+	value = hashtable_get(hashtable, "bob"); 
+	printf("h['bob'] ? %d\n", *value);
+	value = hashtable_get(hashtable, "charlie"); 
+	printf("h['charlie'] ? %d\n", *value);
+
+	return EXIT_SUCCESS;
+}
+

src/udp-client.c

@@ -0,0 +1,68 @@
+/*
+** talker.c -- a datagram "client" demo
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+
+#define SERVERPORT "9119"    // the port users will be connecting to
+
+int main(int argc, char *argv[])
+{
+    int sockfd;
+    struct addrinfo *servinfo, *p;
+    struct addrinfo hints;
+    int rv;
+    int numbytes;
+
+    if (argc != 3) {
+        fprintf(stderr,"usage: talker hostname message\n");
+        exit(1);
+    }
+
+    memset(&hints, 0, sizeof hints);
+    hints.ai_family = AF_UNSPEC;
+    hints.ai_socktype = SOCK_DGRAM;
+
+    if ((rv = getaddrinfo(argv[1], SERVERPORT, &hints, &servinfo)) != 0) {
+        fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(rv));
+        return 1;
+    }
+
+    // loop through all the results and make a socket
+    for(p = servinfo; p != NULL; p = p->ai_next) {
+        if ((sockfd = socket(p->ai_family, p->ai_socktype,
+                p->ai_protocol)) == -1) {
+            perror("talker: socket");
+            continue;
+        }
+
+        break;
+    }
+
+    if (p == NULL) {
+        fprintf(stderr, "talker: failed to create socket\n");
+        return 2;
+    }
+
+    if ((numbytes = sendto(sockfd, argv[2], strlen(argv[2]), 0,
+             p->ai_addr, p->ai_addrlen)) == -1) {
+        perror("talker: sendto");
+        exit(1);
+    }
+
+    freeaddrinfo(servinfo);
+
+    printf("talker: sent %d bytes to %s\n", numbytes, argv[1]);
+    close(sockfd);
+
+    return 0;
+}

src/udp-server.c

@@ -0,0 +1,95 @@
+/*
+** listener.c -- a datagram sockets "server" demo
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+
+#define MYPORT "9119"    // the port users will be connecting to
+
+#define MAXBUFLEN 100
+
+// get sockaddr, IPv4 or IPv6:
+void *get_in_addr(struct sockaddr *sa)
+{
+    if (sa->sa_family == AF_INET) {
+        return &(((struct sockaddr_in*)sa)->sin_addr);
+    }
+
+    return &(((struct sockaddr_in6*)sa)->sin6_addr);
+}
+
+int main(void)
+{
+    int sockfd;
+    struct addrinfo hints, *servinfo, *p;
+    int rv;
+    int numbytes;
+    struct sockaddr_storage their_addr;
+    char buf[MAXBUFLEN];
+    socklen_t addr_len;
+    char s[INET6_ADDRSTRLEN];
+
+    memset(&hints, 0, sizeof hints);
+    hints.ai_family = AF_UNSPEC; // set to AF_INET to force IPv4
+    hints.ai_socktype = SOCK_DGRAM;
+    hints.ai_flags = AI_PASSIVE; // use my IP
+
+    if ((rv = getaddrinfo(NULL, MYPORT, &hints, &servinfo)) != 0) {
+        fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(rv));
+        return 1;
+    }
+
+    // loop through all the results and bind to the first we can
+    for(p = servinfo; p != NULL; p = p->ai_next) {
+        if ((sockfd = socket(p->ai_family, p->ai_socktype,
+                p->ai_protocol)) == -1) {
+            perror("listener: socket");
+            continue;
+        }
+
+        if (bind(sockfd, p->ai_addr, p->ai_addrlen) == -1) {
+            close(sockfd);
+            perror("listener: bind");
+            continue;
+        }
+
+        break;
+    }
+
+    if (p == NULL) {
+        fprintf(stderr, "listener: failed to bind socket\n");
+        return 2;
+    }
+
+    freeaddrinfo(servinfo);
+
+    printf("listener: waiting to recvfrom...\n");
+
+    addr_len = sizeof their_addr;
+    if ((numbytes = recvfrom(sockfd, buf, MAXBUFLEN-1 , 0,
+        (struct sockaddr *)&their_addr, &addr_len)) == -1) {
+        perror("recvfrom");
+        exit(1);
+    }
+
+    printf("listener: got packet from %s\n",
+        inet_ntop(their_addr.ss_family,
+            get_in_addr((struct sockaddr *)&their_addr),
+            s, sizeof s));
+    printf("listener: packet is %d bytes long\n", numbytes);
+    buf[numbytes] = '\0';
+    printf("listener: packet contains \"%s\"\n", buf);
+
+    close(sockfd);
+
+    return 0;
+}