good starting point, finished the guide

1 files changed, 72 insertions, 0 deletions

diff --git a/reference.c b/reference.c
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+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netdb.h>
+#include <arpa/inet.h>
+#include <netinet/in.h>
+
+struct addrinfo {
+    int              ai_flags;     // AI_PASSIVE, AI_CANONNAME, etc.
+    int              ai_family;    // AF_INET, AF_INET6, AF_UNSPEC
+    int              ai_socktype;  // SOCK_STREAM, SOCK_DGRAM
+    int              ai_protocol;  // use 0 for "any"
+    size_t           ai_addrlen;   // size of ai_addr in bytes
+    struct sockaddr *ai_addr;      // struct sockaddr_in or _in6
+    char            *ai_canonname; // full canonical hostname
+
+    struct addrinfo *ai_next;      // linked list, next node
+};
+
+struct sockaddr {
+    unsigned short    sa_family;    // address family, AF_xxx
+    char              sa_data[14];  // 14 bytes of protocol address
+}; 
+
+struct sockaddr_in {
+    short int          sin_family;  // Address family, AF_INET
+    unsigned short int sin_port;    // Port number
+    struct in_addr     sin_addr;    // Internet address
+    unsigned char      sin_zero[8]; // Same size as struct sockaddr
+};
+
+// (IPv4 only--see struct in6_addr for IPv6)
+// Internet address (a structure for historical reasons)
+struct in_addr {
+    uint32_t s_addr; // that's a 32-bit int (4 bytes)
+};
+
+struct sockaddr_storage {
+    sa_family_t  ss_family;     // address family
+
+    // all this is padding, implementation specific, ignore it:
+    char      __ss_pad1[_SS_PAD1SIZE];
+    int64_t   __ss_align;
+    char      __ss_pad2[_SS_PAD2SIZE];
+};
+
+int getaddrinfo(const char *node,     // e.g. "www.example.com" or IP
+                const char *service,  // e.g. "http" or port number
+                const struct addrinfo *hints,
+                struct addrinfo **res);
+
+
+// sockets!
+#include <sys/types.h>
+#include <sys/socket.h>
+
+int socket(int domain, int type, int protocol); 
+
+int s;
+struct addrinfo hints, *res;
+
+// do the lookup
+// [pretend we already filled out the "hints" struct]
+getaddrinfo("www.example.com", "http", &hints, &res);
+
+// again, you should do error-checking on getaddrinfo(), and walk
+// the "res" linked list looking for valid entries instead of just
+// assuming the first one is good (like many of these examples do).
+// See the section on client/server for real examples.
+
+s = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
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