The DIR, LS, and L are commands to list files on a filesystem. DIR was commonly used on MS-DOS, but actually originated from older systems like CP/M and VMS. It is short for "directory". LS is most commonly used to this day on Unix and Linux operating systems. It is short for "list". L is also commonly used to this day on Unix and Linux operating systems. It shows a long directory listing which includes permissions, owner, and file sizes. Since Telehack is simplified, it doesn't matter which OS you're logged into. You may use them interchangeably.
A wildcard is a character which means "unknown" or "all". On Telehack, only the "*" wildcard works, which means "all". For example, to help sort your results to only show all files ending in ".exe", you may use the following:
dir *.exe porthack.exe wardial.exe
You may also search within directory results and within the files themselves by using grep. For example:
dir | grep kit attkit.exe sunoskit.exe
l -l *exe -rwxr-xr-x 1 accentus bin 290600 bsdkit.exe
" l " is a short alternative command for dir include " -l " for a detailed look and " * " to only show this filetype.
This will show you all files with "kit" in the name.