netsplit script

Synopsis

/load netsplit

Description

When a netsplit occurs, an IRC server commonly sends quit messages for people on the disconnected side, followed by join messages when they return. This can cause a lot of scrolling. The netsplit script reduces that output by tracking apparent splits and displaying a timestamped Netsplit message and a subsequent Netjoined message instead of individual departures and returns.

Detection depends on the server's quit text. The script's channel_signoff hook matches a channel, nickname, and two apparent server names containing periods. It rejects names matching its bogus-pattern list or containing consecutive periods. This is a heuristic, not a verified report of network topology: ordinary quit text can resemble a split, and other server formats may not be recognized.

For an accepted split, the script remembers each channel and nickname and groups departures by the ordered pair of server names. It prints one Netsplit at HH:MM:SS (servers) line while that pair's split flag is set. The first remembered person to rejoin clears that flag and prints Netjoined at HH:MM:SS (servers); other remembered returns are silent. This announces the first observed return, not proof that everyone has returned. A further departure for that pair can start another announcement cycle.

Unrecognized signoffs retain normal handling. A candidate rejected by the bogus checks gets the script's replacement signoff line, potentially once per shared channel. The script replaces all join output: unremembered joins receive its own ordinary join line. It does not change server membership or suppress server mode changes.

Commands

These aliases become available after loading:

The script also defines internal aliases and the helper functions $currtime() and $lformat(width text). The former returns local time as HH:MM:SS; the latter pads short text on the right without truncating longer text. Loading can replace aliases with these names, including the generic purge helper.

Cleanup and limitations

A serial-70 timer hook runs netclean on clock events, ordinarily once per observed minute. Expiration is measured from the latest recorded departure for a server pair. There is no guaranteed ten-minute cleanup schedule: disabled clock updates or a stalled client can delay cleanup, and entries expire only when the elapsed time exceeds five minutes. A returning person whose record has expired is displayed as an ordinary join.

Tracking is shared across all server connections and does not include a server reference number. Identical channel/nickname combinations or server pairs on different connections can interfere. Channels are lowercased for keys, while nicknames are encoded without first being lowercased; a change in nickname spelling or case can prevent a return from matching its saved record.

The announcements explicitly use the opnotes output level. Their visibility and destination depend on window level routing. Other hooks, especially replacements for the same serial-zero join or channel-signoff hooks, can change or displace this behavior. Suppressing a channel signoff also prevents the later ordinary signoff hook for that quit.

The encode and decode helpers from builtins must already be loaded; netsplit does not load that dependency itself. No additional package or optional platform feature is required. This is an optional script, not a built-in netsplit detector, and loading it does not create a server-side request. There are no script-specific settings or command return values.

Examples

/load netsplit
/boguspat *bonk* *thud*
/wholeft
/netpurge

boguspat applies to the apparent server names in quit reasons, not to nicknames or channels.

History

This script first appeared in ircII. The retained source identifies itself as version VII and credits Daemon, poxaV, mycroft, and other contributors; its dated modification note is July 3, 1993.

Source references

• script/netsplit: detection, tracking, output, aliases, and cleanup.
• source/parse.c: p_quit and p_join supply hook arguments and implement default output suppression.
• script/builtins: encode and decode wrappers used for tracking keys.
• source/functions.c: userhost supplies the current message's prefix userhost for replacement join output.
• source/clock.c: clock updates dispatch timer hooks.
• source/hook.c: hook matching, serial numbers, and suppression.
• source/levels.c: opnotes output level.