cmd / Clink

Lua and pipes

• Clink's io.popenrw reads are BLOCKING with no peek/timeout in Clink Lua (verified in io_api.cpp). Any protocol consumed from Lua must guarantee a fixed number of records per request - the serve wait-mode contract (exactly 2 records, upheld by Go's renderComplete even on segment panic) exists for this.
• io.popenrw runs the command via %COMSPEC% /c, so 2>nul works in the command string and is REQUIRED - the child's stderr otherwise inherits the console and corrupts the display.
• Clink creates its pipes _O_NOINHERIT and only dups the child ends inheritable (pipe_pair::init), so cmd's death guarantees the daemon's stdin write handle closes.

Windows lifecycle

• There is no SIGPIPE on Windows - stdin EOF is a daemon's ONLY exit signal. Design teardown around fd closure, not signals.
• The cmd feature line for the daemon is serve_enabled = true (Streaming feature in src/shell/cmd.go).

Testing

• luac -p for syntax; a Lua harness with a stubbed Clink API covers logic (lua.exe via winget install DEVCOM.Lua, Clink via winget install chrisant996.Clink).
• Clink itself cannot run headless - live smoke tests stay manual.