fish-shell/share/completions/ln.fish

complete -c ln -s s -l symbolic            -d 'Make symbolic links instead of hard links'
complete -c ln      -l backup              -d 'Make a backup of each existing destination file' -a "none off numbered t existing nil simple never"
complete -c ln -s b                        -d 'Make a backup of each existing destination file'
complete -c ln -s d -l directory           -d 'Allow superuser to attempt to hard link directories'
complete -c ln -s f -l force               -d 'Remove existing destination files'
complete -c ln -s i -l interactive         -d 'Prompt whether to remove destinations'
complete -c ln -s L -l logical             -d 'Dereference TARGETs that are symbolic links'
complete -c ln -s n -l no-dereference      -d 'Treat symlink to directory as if it were a file'
complete -c ln -s P -l physical            -d 'Make hard links directly to symbolic links'
complete -c ln -s S -l suffix              -d 'Override the usual ~ backup suffix'
complete -c ln -s t -l target-directory    -d 'Specify the DIRECTORY in which to create the links' -a '(__fish_complete_directories)'
complete -c ln -s T -l no-target-directory -d 'Treat LINK_NAME as a normal file'
complete -c ln -s v -l verbose             -d 'Print name of each linked file'

complete -c ln -f   -l help                -d 'Display help and exit'
complete -c ln -f   -l version             -d 'Output version information and exit'