服务器修改本地时间踩坑纪实
一.背景知识
如果大家用过Linux的话就会知道,linux下我们通常是使用date命令来获取系统的时间,但是我们有没有想过这个具体的过程呢?我在Ubuntu下面使用strace跟踪了一下date命令的执行过程如下
```
root@ubuntu:~# strace date
execve("/bin/date", ["date"], [/* 65 vars */]) = 0
brk(NULL) = 0x16a3000
access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=97822, ...}) = 0
mmap(NULL, 97822, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f29e04d8000
close(3) = 0
access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "177ELF2113 3 >