/usr/share/fish/completions/sylpheed.fish is in fish-common 2.4.0-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 | #completion for sylpheed
complete -c sylpheed -l exit --description 'Exit sylpheed'
complete -c sylpheed -l debug --description 'Debug mode'
complete -c sylpheed -l help --description 'Display help and exit'
complete -c sylpheed -l version --description 'Output version information and exit'
complete -r -c sylpheed -l compose --description 'Open composition window with address'
complete -r -c sylpheed -l attach --description 'Open composition window with attached files'
complete -r -c sylpheed -l receive --description 'Receive new messages'
complete -r -c sylpheed -l receive-all --description 'Receive new messages of all accounts'
complete -r -c sylpheed -l send --description 'Send all queued messages'
complete -r -c sylpheed -l status --description 'Show the total number of messages for folder'
complete -r -c sylpheed -l status-full --description 'Show the total number of messages for each folder'
complete -r -c sylpheed -l configdir --description 'Specify directory with configuration files'
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