How to join multiple lines of file names into one with custom delimiter?

EDIT: Simply "ls -m" If you want your delimiter to be a comma

Ah, the power and simplicity !

ls -1 | tr '\n' ','

Change the comma "," to whatever you want. Note that this includes a "trailing comma" (for lists that end with a newline)

Similar to the very first option but omits the trailing delimiter

ls -1 | paste -sd "," -