Bash built-in commands provides users the most essential tools. If you want to utilize the advanced features, you need to utilize the external commands.
If you need a list of bash built-in commands, you can find them here.
If you need a list of bash Shell environment variables, you can find them here.
Here is a list of the external commands.
| Command | Description |
| bzip2 | Compression using the Burrows-Wheeler block sorting text compression algorithm and Huffman coding. |
| cat | List the contents of the specified file. |
| chage | Change the password expiration date for the specified system user account. |
| chfn | Change the specified user account’s comment information. |
| chgrp | Change the default group of the specified file or directory. |
| chmod | Change system security permissions for the specified file or directory. |
| chown | Change the default owner of the specified file or directory. |
| chpasswd | Read a file of login name and password pairs and update the passwords. |
| chsh | Change the specified user account’s default shell. |
| compress | Original Unix file compression utility. |
| cp | Copy the specified files to an alternate location. |
| date | Display the date in various formats. |
| df | Display current disk space statistics for all mounted devices. |
| du | Display disk usage statistics for the specified filepath. |
| file | View the file type of the specified file. |
| find | Perform a recursive search for files. |
| finger | Display information about user accounts on the Linux system or a remote system. |
| free | Check available and used memory on the system. |
| grep | Search a file for the specified text string. |
| groupadd | Create a new system group. |
| groupmod | Modify an existing system group. |
| gzip | The GNU Project’s compression using Lempel-Ziv compression. |
| head | Display the first portion of the specified file’s contents. |
| killall | Send a system signal to a running process based on process name. |
| less | Advanced viewing of file contents. |
| link | Create a link to a file using an alias name. |
| ls | List directory contents. |
| mkdir | Create the specified directory under the current directory. |
| more | List the contents of the specified file, pausing after each screen of data. |
| mount | Display or mount disk devices into the virtual filesystem. |
| mv | Rename a file. |
| nice | Run a command using a different priority level on the system. |
| passwd | Change the password for a system user account. |
| ps | Display information about the running processes on the system. |
| pwd | Display the current directory. |
| renice | Change the priority of a running application on the system. |
| rm | Delete the specified file. |
| rmdir | Delete the specified directory. |
| sort | Organize data in a data file based on the specified order. |
| stat | View the file statistics of the specified file. |
| sudo | Run an application as the root user account. |
| tail | Display the last portion of the specified file’s contents. |
| tar | Archive data and directories into a single file. |
| touch | Create a new empty file, or update the timestamp on an existing file. |
| top | Display the active processes, showing vital system statistics. |
| umount | Remove a mounted disk device from the virtual filesystem. |
| uptime | Display information on how long the system has been running. |
| useradd | Create a new system user account. |
| userdel | Remove an existing system user account. |
| usermod | Modify an existing system user account. |
| vmstat | Produce a detailed report on memory and CPU usage on the system. |
| which | Find the location of an executable file |
| zip | Unix version of the Windows PKZIP program. |
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