Factorio supports the RCON (Remote Console) Protocol for mods to run commands externally.
The official wiki barely documents RCON
The wiki just points to https://developer.valvesoftware.com/wiki/Source_RCON_Protocol
The first RCON client has a special ability to retrieve game logs like chat and commands. Send requests with ID of 0 at a regular interval to retrieve.
Some clients like https://github.com/gorcon/rcon-cli always use ID=0 which may mislead what the response should look like
This may also break your client! Code parsing command responses that does not want logs must avoid ID=0 (eg with sequential ids instead of random). You should not simply skip the first line either as chat messages may be inserted too.
> /time
2024-04-10 02:28:53 [CHAT] <server>: random chat message
1 day, 11 hours, 1 minute and 26 seconds
> /c rcon.print('asdf')
2024-04-10 02:26:58 [CHAT] <server>: random chat message
2024-04-10 02:27:07 [COMMAND] <server> (command): rcon.print('asdf')
asdf
Instead of communicating via script-output files or parsing game.log commands use
the rcon.print() method. Sends messages back to the connection.
Normal /command requests do not include error messages in RCON Response.
A blank response means both "command success" and "error in logs".
This may be surprising when moving from in-game console experiments to modding.
Instead of a normal command use /silent-command which returns most error messages.
For more garantees of success, append rcon.print('done'') validation check at the
end of all commands and confirm it's in the output.
/c
/silent-command
On fresh games achievements disable some console commands.