os.File clean up + socket.v (dial())

vlib/net/socket.v

@@ -0,0 +1,78 @@
+module net
+
+#include <netdb.h>
+#include <sys/types.h>
+#include <netinet/in.h>
+#include <sys/socket.h>
+#include <errno.h>
+
+struct Conn {
+pub: 
+	sockfd int
+}
+
+struct Listener {
+	listener   int
+	their_addr voidptr
+}
+
+import const ( 
+	AF_UNSPEC 
+	SOCK_STREAM 
+	AI_PASSIVE 
+) 
+
+struct C.addrinfo {
+mut: 
+	ai_family int 
+	ai_socktype int 
+	ai_flags int 
+	ai_protocol int 
+	ai_addrlen int 
+	ai_next voidptr 
+	ai_addr voidptr 
+} 
+
+fn dial(addr string, port int) Conn {
+	println('net.dial("$addr":$port)')
+	mut hints := C.addrinfo{} 
+	servinfo := &C.addrinfo{!} 
+	mut rp := &C.addrinfo{!} 
+	mut sockfd := -1
+	// allow IPv4 or IPv6
+	hints.ai_family = AF_UNSPEC 
+	// avoid name lookup for port
+	// hints.ai_flags = AI_NUMERICSERV 
+	hints.ai_socktype = SOCK_STREAM 
+	hints.ai_flags = AI_PASSIVE 
+	strport := '$port'
+	connbad := Conn{}
+	c_addr := addr.cstr()
+	rv := C.getaddrinfo(c_addr, strport.cstr(), &hints, &servinfo)
+	if rv != 0 { 
+		println('Getaddrinfo failed ')
+		return connbad
+	}
+	// Loop through all the results and connect to the first we can
+	for rp = servinfo; !isnil(rp); rp = rp.ai_next  { 
+		sockfd = C.socket(rp.ai_family, rp.ai_socktype, rp.ai_protocol) 
+		if sockfd == -1 {
+			continue 
+		} 
+		if C.connect(sockfd, rp.ai_addr, rp.ai_addrlen) {
+			C.close(sockfd) 
+			continue 
+		} 
+		break 
+	}
+	if sockfd == -1 {
+		println('socket: Cannot connect to host')
+		return connbad
+	}
+	C.freeaddrinfo(servinfo) 
+	conn := Conn {
+		sockfd: sockfd,
+	}
+	return conn
+}
+