Clarify -ipcbind syntax when using max-connections with the default Unix socket #36657

The -ipcbind option supports the default Unix socket address unix and per-address connection limits using the max-connections option.

The examples for the connection-limit syntax use -ipcbind=unix:,max-connections=8, with a colon after unix. It may be worth clarifying whether this colon is required when adding socket options to the default Unix socket address.

Is -ipcbind=unix:,max-connections=8 the intended syntax for setting a connection limit on the default socket, and is the colon required to distinguish the socket address from the following options?

If so, documenting this distinction in the -ipcbind help text could make the syntax easier to understand.

Related PR

#35037

I have not independently tested the alternative syntax. This report is asking for clarification rather than asserting that a confirmed bug exists.

-ipcbind=unix:,max-connections=8 is the intended syntax. Testing both with the colon and without it, the former would bind the default socket to 8 connection slots, while the latter would fail with an unrecognized address error.

The parser only processes inline options for addresses starting with unix:. The empty path after the colon would still select the default socket as it would for unix. Bare unix works as a shorthand when used without the options.

Looking at this, the parser could be updated to use it without the colon, seeing as unix is a valid address. Reasonably speaking, the form without the colon should work. The help text could be further clarified, or the parser could be modified to support it without the colon.