Double horizontal bar and single horizontal bar in Shell parameters

A shell process is a process that executes other processes, but when a command is executed, the shell process instructs the kernel to execute the specified program separately as another process and write the output to the terminal. With the command options, we can modify the behavior of the command execution. command line options can be divided into short command-line options and long command-line options. Short command-line options are made up of letters, and long command-line options are made up of words. Short command-line options use a single horizontal bar "-" before the option, and a long command-line option before using a double bar "--". If you need to enter a parameter for an option after the option, the short command-line options and parameters are separated by a space, and the long command-line option uses the equals sign "=" connection options and parameters. By adding the option "--help", "-H", or "after the command"-. ", we can get a command of help information.