therion is not a graphical program and can be executed from a shell (a command line prompt). The syntax is
By default the configuration file is thconfig. For instance xtherion invokes therion with the command "therion -x thconfig".

therion has several options (these can be given in long form too):

• -v: displays the version of the program;
• -h: (help) writes a short summary of the command options;
• -d: activates the debug mode;
• -g: generates a new configuration file;
• -u: update the configuration file;
• -l log_file: writes the logs on log_file;
• -L: does not generates any log;
• -q: (quiet) executes with fewer messages;
• -i: ignores the comments when writing a configuration file;
• -x: generates the file .xth-thconfig with the info for xtherion
• -p path: specifies the search path
• -s file: specifies a source file.

There are also options to display the configuration:

• --print-encodings
• --print-tex-encoding
• --print-init-file
• --print-environment