Linux study notes [1] -- simple commands

Linux study notes [1] & mdash; simple command 1. add the environment variable you want to modify in the/etc/profile file to take effect permanently. 2. what is the shell obtained by the user by default? $ Cat/etc/passwd3, bash command memory function, you can press the up or down key to switch to use... linux study notes [1] -- simple command 1. add the environment variable you want to modify in the/etc/profile file to take effect permanently. 2. what is the shell obtained by the user by default? $ Cat/etc/passwd 3. bash command memory function. you can press the up/down key to switch to the used command/where is the usage history of this command ?~ /. Bash_history 4. set the alias of the command: $ alias lm = 'ls-AL'. lm is the command we set. it will be executed like the command on the right. 5. Shell Script. You can execute some input commands several times in a row. Just like a batch file in windows.