nextcloud-desktop/doc/options.rst

You have the option of starting your ownCloud desktop client with the owncloud command. The following options are supported:

owncloud -h or owncloud --help

Displays all command options.

The other options are:

--logwindow

Opens a window displaying log output.

--logfile <filename>

Write log output to the file specified. To write to stdout, specify - as the filename.

--logdir <name>

Writes each synchronization log output in a new file in the specified directory.

--logexpire <hours>

Removes logs older than the value specified (in hours). This command is used with --logdir.

--logflush

Clears (flushes) the log file after each write action.

--confdir <dirname>

Uses the specified configuration directory.