How can I generate a comma-delimited, case-insensitive list of the first characters of the names of the files and directories in a directory, excluding initial . items, without duplicates?  I don't need it to be recursive - just one level deep.For example, from a directory where ls producesdrwxr-xr-x+ 10 bryan  staff   340B Jun  6 15:32 .drwxrwx---@ 27 bryan  staff   918B Jun  6 15:29 ..-rw-r--r--@  1 bryan  staff   6.0K Jun  6 15:32 .secretsdrwxr-xr-x+  2 bryan  staff    68B Jun  6 15:30 Apoptosisdrwxr-xr-x+  2 bryan  staff    68B Jun  6 15:32 Fanciful Notions-rwxr-x---@  1 bryan  staff   351B Jun  2 16:57 Pungent-rwxr-x---@  1 bryan  staff   351B Jun  2 16:57 Zoophilia-rwxr-x---@  1 bryan  staff   351B Jun  2 16:57 addled_symbionts-rwxr-x---@  1 bryan  staff   351B Jun  2 16:57 putriddrwxr-xr-x+  2 bryan  staff    68B Jun  6 15:30 zuegma mandegreenI'd like to returna, f, p, zI'm using BSD, am a nube, and can't quite make this work.
Get Comma Delimited List of Initials of Items in Directory?
shell;text processing;ls