A Comprehensive Collection of Embedded Linux Command Lines

Embedded Linux Command Line Reference

The embedded Linux command line is a powerful tool for system administrators and developers working with embedded systems. It provides a command-line interface to interact with the underlying operating system and perform various tasks such as file management, process control, and networking. In this article, we will provide a comprehensive reference guide to the most commonly used embedded Linux commands.

File Management Commands

One of the fundamental tasks in embedded Linux is file management. The following are some of the commonly used file management commands:

– `ls`: Lists the contents of a directory. It can display files and directories, along with their attributes such as permissions, ownership, and modification time. For example, `ls -l` shows detailed information about the files and directories.

– `cd`: Changes the current working directory. You can use `cd` followed by the directory path to navigate to a different directory. For example, `cd /home/user` changes the current directory to the `/home/user` directory.

– `mkdir`: Creates a new directory. You can use `mkdir` followed by the directory name to create a new directory. For example, `mkdir new_dir` creates a new directory named `new_dir`.

– `rm`: Removes files or directories. The `rm` command can be used to delete files or directories. Be careful when using `rm` as it permanently deletes the files and cannot be undone. For example, `rm file.txt` deletes the file `file.txt`.

– `cp`: Copies files or directories. The `cp` command is used to copy files or directories from one location to another. You can use `cp` followed by the source file or directory and the destination. For example, `cp source.txt destination.txt` copies the file `source.txt` to `destination.txt`.

– `mv`: Moves or renames files or directories. The `mv` command is used to move files or directories to a different location or rename them. For example, `mv file.txt new_file.txt` moves the file `file.txt` to `new_file.txt` or renames it.

Process Control Commands

Managing processes is another important aspect of embedded Linux. The following are some of the commonly used process control commands:

– `ps`: Displays information about running processes. The `ps` command shows a list of processes currently running on the system. You can use various options with `ps` to get more detailed information. For example, `ps -ef` shows all processes with their full process ID and parent process ID.

– `top`: Displays a dynamic real-time view of running processes. The `top` command provides a constantly updated view of the system’s processes, including CPU usage, memory usage, and process priorities. You can use `top` to monitor system performance and identify processes that are consuming excessive resources.

– `kill`: Sends a signal to a process to terminate it. The `kill` command is used to send a signal to a process to terminate it. You can use the process ID and the signal number to send the signal. For example, `kill -9 1234` sends a SIGKILL signal (signal number 9) to the process with ID 1234 to terminate it immediately.

– `nice`: Sets the priority of a process. The `nice` command is used to set the priority of a process. A lower priority value means a higher priority for the process. You can use `nice` followed by the priority value and the command to run the process with the specified priority. For example, `nice -n 10 command` runs the `command` with a priority of 10.

Networking Commands

Embedded systems often need to communicate over a network. The following are some of the commonly used networking commands in embedded Linux:

– `ifconfig`: Displays and configures network interfaces. The `ifconfig` command is used to display information about network interfaces and configure their IP addresses, subnet masks, and other network parameters. For example, `ifconfig eth0 192.168.1.100 netmask 255.255.255.0` sets the IP address of the eth0 interface to 192.168.1.100 with a subnet mask of 255.255.255.0.

– `ping`: Tests network connectivity. The `ping` command is used to test the connectivity between two network devices by sending ICMP echo requests and receiving responses. For example, `ping 192.168.1.1` tests the connectivity to the IP address 192.168.1.1.

– `route`: Displays and manages routing tables. The `route` command is used to display the system’s routing table and add or delete routes. For example, `route add -net 192.168.2.0 netmask 255.255.255.0 gw 192.168.1.1` adds a route to the 192.168.2.0 network with a subnet mask of 255.255.255.0 via the gateway 192.168.1.1.

– `telnet`: Establishes a remote terminal connection. The `telnet` command is used to establish a remote terminal connection to a remote server. You can use `telnet` followed by the IP address or hostname and the port number to connect. For example, `telnet 192.168.1.100 23` connects to the remote server at IP address 192.168.1.100 on port 23.

Other Useful Commands

In addition to the above commands, there are several other useful commands in embedded Linux:

– `su`: Allows you to switch to a different user. The `su` command is used to switch to a different user with different privileges. You can use `su` followed by the username to switch to that user. For example, `su user` switches to the `user` user.

– `sudo`: Allows you to execute commands with root privileges. The `sudo` command is used to execute commands with root privileges. You need to have the appropriate permissions to use `sudo`. For example, `sudo command` executes the `command` with root privileges.

– `man`: Displays the manual page for a command. The `man` command is used to display the manual page for a specific command. You can use `man` followed by the command name to view the manual page. For example, `man ls` displays the manual page for the `ls` command.

– `history`: Displays the command history. The `history` command is used to display the list of commands that have been executed in the current shell session. You can use the up and down arrows to navigate through the command history and press Enter to execute a command.

Conclusion

The embedded Linux command line provides a powerful set of tools for system administrators and developers working with embedded systems. By mastering these commands, you can perform various tasks such as file management, process control, and networking with ease. This reference guide has covered some of the most commonly used embedded Linux commands, but there are many more commands available depending on the specific requirements of your embedded system. It is recommended to refer to the official documentation and online resources for more detailed information about the embedded Linux command line.