linux嵌入式系统修改时区

一. 网址参考

　　1. 修改系统时区 /etc/localtime

二. 实践

　　1. 对/etc/localtime修改软链接，命令如下：

//1. 先判断/etc/localtime是否存在，如果存在，则先删除
    if （access("/etc/localtime", F_OK) == 0）
        ret = unlink("/etc/localtime");

//2. 重新创建软链接
    ret = symlink("/usr/share/zoneinfo/posix/Etc/GMT-8", "/etc/localtime");     //注意：其GMT-8对应于GMT+8(东八区)

　　2. 注意：当时区设置为GMT+8(东八区)， 用posix/Etc方式需要把软链接设置为GMT-8，刚好相反；表格如下：

 1 typedef struct _sdmp_tz_list {
 2     char *display;
 3     char *actual;
 4 }sdmp_tz_list_t;
 5 
 6 static sdmp_tz_list_t tz_list[] = {
 7     {"GMT-12", "GMT+12"}, {"GMT-11", "GMT+11"}, {"GMT-10", "GMT+10"},
 8     {"GMT-9",  "GMT+9"},  {"GMT-8",  "GMT+8"},  {"GMT-7",  "GMT+7"},
 9     {"GMT-6",  "GMT+6"},  {"GMT-5",  "GMT+5"},  {"GMT-4",  "GMT+4"},
10     {"GMT-3",  "GMT+3"},  {"GMT-2",  "GMT+2"},  {"GMT-1",  "GMT+1"},
11     {"GMT-0",  "GMT+0"},  {"GMT+0",  "GMT-0"},  {"GMT+1",  "GMT-1"},
12     {"GMT+2",  "GMT-2"},  {"GMT+3",  "GMT-3"},  {"GMT+4",  "GMT-4"},
13     {"GMT+5",  "GMT-5"},  {"GMT+6",  "GMT-6"},  {"GMT+7",  "GMT-7"},
14     {"GMT+8",  "GMT-8"},  {"GMT+9",  "GMT-9"},  {"GMT+10", "GMT-10"},
15     {"GMT+11", "GMT-11"}, {"GMT+12", "GMT-12"}
16 };