/**
* "break" statement
*/
dobreak() {
loop_t *ptr;
if ((ptr = readloop ()) == 0)
return;
gen_modify_stack (ptr->stack_pointer);
gen_jump (ptr->exit_label);
}
int main(int argc, char** argv)
{
int c;
struct addrinfo* ai;
char* h;
opterr = 0; /* don't want getopt() writing to stderr */
while ((c = getopt(argc, argv, "v")) != -1) {
switch (c) {
case 'v':
verbose++;
break;
case '?':
err_quit("unrecognized option: %c", c);
}
}
if (optind != argc - 1) err_quit("usage: ping [ -v ] <hostname>");
host = argv[optind];
pid = getpid() & 0xffff; /* ICMP ID field is 16 bits */
Signal(SIGALRM, sig_alrm);
ai = Host_serv(host, NULL, 0, 0);
h = Sock_ntop_host(ai->ai_addr, ai->ai_addrlen);
printf("PING %s (%s): %d data bytes\n",
ai->ai_canonname ? ai->ai_canonname : h, h, datalen);
/* 4initialize according to protocol */
if (ai->ai_family == AF_INET) {
pr = &proto_v4;
#ifdef IPV6
} else if (ai->ai_family == AF_INET6) {
pr = &proto_v6;
if (IN6_IS_ADDR_V4MAPPED(
&(((struct sockaddr_in6*)ai->ai_addr)->sin6_addr)))
err_quit("cannot ping IPv4-mapped IPv6 address");
#endif
} else
err_quit("unknown address family %d", ai->ai_family);
pr->sasend = ai->ai_addr;
pr->sarecv = Calloc(1, ai->ai_addrlen);
pr->salen = ai->ai_addrlen;
readloop();
exit(0);
}
/* Read file FN into set<word> S, then print every (word, count)
* pair to stdout.*/
void tokenize_file(const char *fn, set *s, int case_sensitive) {
int fd = open(fn, O_RDONLY, 0);
int skipped, res;
if (fd == -1) { /* warn and skip it */
perror(fn);
printf(" SKIP\n");
} else {
skipped = readloop(fd, s, case_sensitive, scanner);
res = close(fd);
assert(res == 0);
printf(skipped ? " SKIP\n" : " DONE\n");
}
}
/*
* Create a new note
*/
void add_new_note(void) {
struct vnote *v;
v = vnote_new();
if (v) {
v->uid = malloc(128);
generate_uuid(v->uid);
v->color_red = pastel_palette[3][0];
v->color_green = pastel_palette[3][1];
v->color_blue = pastel_palette[3][2];
v->body = strdup(_("Click on any note to edit it."));
write_vnote_to_server(v);
vnote_free(v);
}
readloop(readfwd, eUseDefault);
}
/**
* "for" statement
*/
dofor() {
loop_t loop;
loop_t *p;
loop.symbol_idx = local_table_index;
loop.stack_pointer = stkp;
loop.type = WSFOR;
loop.test_label = getlabel ();
loop.cont_label = getlabel ();
loop.body_label = getlabel ();
loop.exit_label = getlabel ();
addloop (&loop);
p = readloop ();
needbrack ("(");
if (!match (";")) {
expression (YES);
need_semicolon ();
}
generate_label (p->test_label);
if (!match (";")) {
expression (YES);
gen_test_jump (p->body_label, TRUE);
gen_jump (p->exit_label);
need_semicolon ();
} else
p->test_label = p->body_label;
generate_label (p->cont_label);
if (!match (")")) {
expression (YES);
needbrack (")");
gen_jump (p->test_label);
} else
p->cont_label = p->test_label;
generate_label (p->body_label);
statement (NO);
gen_jump (p->cont_label);
generate_label (p->exit_label);
local_table_index = p->symbol_idx;
stkp = gen_modify_stack (p->stack_pointer);
delloop ();
}
int main(int argc, char **argv)
{
int n;
struct addrinfo *ai;
char *h;
opterr = 0; /* don't want getopt() writing to stderr */
/* 只实现ping的一个参数选项-v供查询 */
/* 有关getopt函数的使用可以查阅相关资料 */
while( (n = getopt(argc, argv, "v")) != -1)
{
switch(n)
{
case 'v':
verbose++;
break;
case '?':
printf("unrecognize option: %c\n", n);
exit(1);
}
}
if(optind != argc-1)
{
perror("usage: ping [ -v ] <hostname>");
exit(1);
}
host = argv[optind];
pid = getpid() & 0xffff; /* ICMP ID field is 16 bits */
MySignal(SIGALRM, sig_alrm);
MySignal(SIGINT, statistics);
/* 将主机名和服务名映射到一个地址，并返回指向addrinfo的指针 */
ai = host_serv(host, NULL, 0, 0);
/* 将网络字节序的地址转换为字符串格式地址，并返回该字符串的指针 */
h = Sock_ntop_host(ai->ai_addr, ai->ai_addrlen);
/* 显示PING的主机名、地址与数据字节数 */
printf("PING %s (%s) %d bytes of data.\n", ai->ai_canonname ? ai->ai_canonname : h, h, datalen);
/* initialize according to protocol */
if(ai->ai_family == AF_INET)
{
pr = &proto_v4;/* proto结构指针pr指向对应域的结构，这里是IPv4域的结构 */
#ifdef IPV6
}else if(ai->family == AF_INET6)
{
pr = &proc_v6;
if(IN6_IS_ADDR_V4MAPPED(&(((struct sockaddr_in6 *)ai->ai_addr)->sin6_addr)))
{
perror("connot ping IPv4-mapped IPv6 address");
exit(1);
}
#endif
}else
{
printf("unknown address family %d", ai->ai_family);
exit(1);
}
pr->sasend = ai->ai_addr;/* 发送地址赋值 */
pr->sarecv = (struct sockaddr *)Calloc(1, ai->ai_addrlen);
pr->salen = ai->ai_addrlen;/* 地址的大小 */
/* 处理数据 */
readloop();
exit(0);
}
