In MPlayer, you can use the -shuffle command line option to play files in a random order. For example, to play all the files in the current directory in a random order, you can use the following command:
mplayer -shuffle *
You can also use the -playlist command line option to play files from a playlist file in a random order:
mplayer -shuffle -playlist myplaylist.m3u
Another way is to use the -random command line option to play files in a random order.
mplayer -random *
You can also use the -loop command line option to repeat the random playback indefinitely.
mplayer -shuffle -loop 0 *
Please note that if you want to shuffle a specific set of files, you need to specify the files in the command line.
Also, you can use the -playlist option to specify the files that you want to shuffle.
It is also recommended to check the MPlayer documentation for more information about the available command line options.