The following command can be used to create a SSH Tunneling which forwards any connection to port 1234 on the local machine to port 4321 on localhost via example.com
ssh -N -L 1234:localhost:4321 -p 22 -i ~/.ssh/id_rsa username@example.com
For more information about the flags, please refer https://explainshell.com/explain?cmd=ssh+-L+-N++-f
-EOF-
1. Show current hostname
hostname
2. Edit `/etc/rc.conf`
vim /etc/rc.conf
And modify the hostname
hostname="new-freebsd-hostname"
3. Edit `/etc/hosts`
vim /etc/hosts
and add new hostname mapping
::1 new-freebsd-hostname
127.0.0.1 new-freebsd-hostname
-EOF-
To list clang’s pre-defined macros for clang, run:
clang -x c /dev/null -dM -E
To list gcc’s pre-defined macros for gcc, run:
gcc -x c /dev/null -dM -E
The macros are used for checking which OS(platform) is compiled at compiling time:
Linux and Linux-derived __linux__
Darwin (Mac OS X and iOS) __APPLE__
FreeBSD __FreeBSD__
Ref Guide to predefined macros in C++ compilers (gcc, clang, msvc etc.)
Run the following command in the current terminal:
echo $0
Then it will output something like this:
-sh
OR run:
ps -p $$
To see what shells are available? run:
cat /etc/shells
早期的 Chrome 可以直接在地址栏里点击前面的锁图标就能在查看到网站的SSL证书信息，这么便利的入口后来却被去掉了。在最新版的 Chrome 60 中对该功能做了妥协，需要用户手动开启，开启的方式则是去到 Chrome 的启动设置标记（
chrome://flags/#show-cert-link
）中启用 Show certificate link 功能，并重启 Chrome 。
重启 Chrome 后点击网址前的 Secure 便可以看到 Certificate 菜单。
-EOF-