nextcloud-desktop/doc/options.rst

When invoking the client from the command line, the following options are supported:

-h, --help

shows all the below options (opens a window on Windows)

--logwindow

open a window to show log output.

--logfile <filename>

write log output to file <filename>. To write to stdout, specify - as filename

--logdir <name>

write each sync log output in a new file in directory <name>

--logexpire <hours>

removes logs older than <hours> hours. (to be used with --logdir)

--logflush

flush the log file after every write.

--confdir <dirname>

Use the given configuration directory.