Disambiguation: log

Do you mean the log command or the log function?

Form	Meaning
`/log ...`	Create and manage independent logfiles that copy selected display output to disk. With no arguments, list registered logfiles.
`$log(number)`	Return the natural logarithm of a number. This mathematical function does not read, create, or control a logfile.
`/set log on`	Enable session logging through the log setting, using the configured session logfile.
`/window log on`	Enable logging for the selected window through window log.

The two logging controls in the final rows are separate from the independent logs managed by /log. The shared word does not imply shared arguments, defaults, return values, or error handling. Follow the appropriate page for those details.

For example, /echo $log(1) displays 0; it does not start logging. /log displays the independent-log list rather than evaluating a mathematical expression. These are local client interfaces and do not request an IRC server operation by themselves.

Source references

source/logfiles.c: logcmd manages independent logfiles.
source/functions.c: registers log as a mathematical wrapper around the C library's natural logarithm.
source/vars.c: session logging setting.
source/window.c: per-window logging control.