# Adding "Reboot" command
### Create New Application
**Create New Application**
#### Select Board
**Select Project**
### Coding Explained
You can check the cmd functions in the \`usrcmd.c\` file.
The CLI (Command Line Interface) provides a way for users to interact with the system through text-based commands. Here is the detail of each function:
* `cmd_table_t`: This is a struct that includes a command name, a description, and a function that is executed when the command is entered. The CLI (Command Line Interface) provides a way for users to interact with the system through text-based commands. Here is the detail of each function:
* `cmd_table_t`: This is a struct that includes a command name, a description, and a function that is executed when the command is entered.
* `cmdlist[]`: This is a list of the custom commands available in the shell. Each command corresponds to a specific function that is executed when the command is entered.
* `usrcmd_execute()`: This function executes a given command by looking it up in the cmdlist and calling its corresponding function.
* `usrcmd_ntopt_callback()`: This is the callback function for the command parsing library. It is invoked when a command is entered, and it executes the appropriate function based on the entered command.
* `Command Functions`: Functions like usrcmd\_help(), usrcmd\_info(), usrcmd\_clear(), etc. are the implementations of the custom commands. They are executed when the corresponding command is entered into the shell.
* `usrcmd_task()`: This function is where the command line interface starts. It initializes the shell, sets the prompt, and then starts executing commands.
The new commands that we added are usrcmd\_history(), usrcmd\_reboot(), and usrcmd\_kill().
## ✅ Create the commands of `usrcmd_reboot`
`usrcmd_reboot` reboots the system by using the NVIC\_SystemReset function which resets the processor and all peripheral devices to their default state.
**Step-by-step guide on how to create the `usrcmd_reboot`**
### **1. Function Prototype:**
You have to declare the function prototype for usrcmd\_reboot. The prototype of the function is as follows:
```c
static int usrcmd_reboot(int argc, char **argv);
```
### **2. Function Definition:**
Now let's define the usrcmd\_reboot function. Here, it will print a message and then call NVIC\_SystemReset() to perform a system reboot.
```c
static int usrcmd_reboot(int argc, char **argv)
{
printf("Rebooting the system...\n");
NVIC_SystemReset();
return 0;
}
```
### **3. Command Registration:**
In the `cmdlist[]` structure, register the `reboot` command to map it to the `usrcmd_reboot` function. Add the following line in the `cmdlist[]` structure:
```c
{ "reboot", " Reboot the system of board", usrcmd_reboot },
```
## ✅ Create the commands of `usrcmd_kill`
`usrcmd_reboot` reboots the system by using the NVIC\_SystemReset function which resets the processor and all peripheral devices to their default state.
**Step-by-step guide on how to create the `usrcmd_reboot`**
### **1. Function Prototype:**
Declare the function prototype for `usrcmd_kill`:
```c
static int usrcmd_kill(int argc, char **argv);
```
### **2. Function Definition:**
Define the `usrcmd_kill` function. This function will typically take the process ID as a parameter from the command line arguments and terminate that process.
```c
static int usrcmd_kill(int argc, char **argv)
{
if (argc != 2) {
printf("Usage: kill \n");
return 1;
}
int pid = atoi(argv[1]);
if (kill(pid) != 0) {
printf("Failed to kill process %d\n", pid);
return 1;
}
printf("Process %d killed\n", pid);
return 0;
}
```
### **3. Command Registration:**
Add the `kill` command to the `cmdlist[]` structure to map it to the `usrcmd_kill` function. Add the following line in the `cmdlist[]`
```c
{ "kill", "Kill a process with a specific PID", usrcmd_kill },
```
This registers the kill command such that it will call the usrcmd\_kill function when invoked.
