What command would you use to check current disk usage?

The command used to check current disk usage is 'df.' This command stands for "disk free" and it provides a summary of available and used disk space on filesystems. When executed without any options, 'df' displays the filesystem names, their sizes, the amount of space used, available space, and the percentage of space used. It is particularly useful for understanding how much disk space is utilized and how much is free across all mounted filesystems.

'du' is also a command related to disk usage, but it is used to estimate file and directory space usage rather than providing an overview of the entire filesystem as 'df' does. If you want to check how much space individual files or directories consume, 'du' would be the appropriate choice.

The other options, 'checkdisk' and 'diskusage,' are not valid commands in Linux. 'checkdisk' is not a native Linux command; it is associated with Windows operating systems. Similarly, 'diskusage' is not a standard command in Linux. Hence, 'df' is the correct command for checking current disk usage accurately across filesystems.