Someone once said that learning Linux without shell programming means that you don't understand Linux. To master shell programming, a lot of practice is required. Beginners can use the shell to print hello world and start learning! Shell script programming requires the following rules:
1. The name of the shell script is generally in English, uppercase and lowercase;
2. Special symbols and spaces cannot be used for naming;
3. The shell script suffix ends with .sh;
4. It is not recommended that the shell be pure numbers, generally named after the script function;
5. The first line of the shell script content starts with #! / Bin / bash;
6. Use uppercase letters for the names of variables in shell scripts. You cannot use "-" between letters, you can use "_";
7. Variable names of shell scripts cannot start with numbers or special symbols.
The following is the first shell script, the script name is: first_shell.sh, the code content is as follows:
#! / bin / bash fixed format, define the shell type used by the script;
#This is my first shell # signifies a comment and has no practical meaning, Shell will not parse it
#By author lee represents the script creator, # signifies comments
echo "Hello World!" script main command, execute the script to present content
