Linux shell programming location parameter, linuxshell

Linux shell programming location parameter, linuxshell

Location parameters are a special shell variable used to pass parameters to the program when running shell.

$0 indicates the Script Name;

$1 indicates the first parameter, $2 indicates the second parameter, and so on. When the number is greater than or equal to 10, it must be enclosed in braces, such as $ {10}, ${100 }.

$ @ Is the same as $ *, indicating the values of all parameters starting from $1, separated by spaces.

$ # Indicates the number of parameters passed in when the program is running.

$? Indicates the exit status of the program, 0 indicates no error, and non-0 indicates an error.

$ Indicates the process number that runs the script program.