Introduction to LINUX ---- shell script syntax

For a beginner in LINUX, I see shell script. Note that the syntax shell scripts is a program written by using shell functions (syntax and command) combined with regular expressions, pipeline commands, data stream redirection, and other functions, is a plain text file that can be executed without compilation. 1. The Service Startup interfaces of linux systems are all in the/etc/init. d/directory. 2. read: the command for reading the keyboard. Similar to C-language scanf and C ++-language cin. Format: read-p "please input...:" filename: Use the content entered by the keyboard as the content of the variable filename. 3 echo: Variable display command. Echo $ (computational formula) is used for the display of numerical calculations. There is no space between (or not executed. 4. variable setting rules:. if the variable content requires other commands to provide information, you should use: variable name = $ (command) or variable name = 'COMMAND '(SLR number here)