proc ::pd_connect::pd_readsocket {} {
    variable pd_socket
    variable cmds_from_pd
    if {[eof $pd_socket]} {
        # if we lose the socket connection, that means pd quit, so we quit
        close $pd_socket
        exit
    }
    append cmds_from_pd [read $pd_socket]
    if {[string index $cmds_from_pd end] ne "\n" || \
            ![info complete $cmds_from_pd]} {
        puts -nonewline stderr "A"
    } else {
        if {![catch {uplevel #0 $cmds_from_pd} errorname]} {
            set cmds_from_pd ""
            puts -nonewline stderr "e"
        } else {
            global errorInfo
            switch -regexp -- $errorname {
                "missing close-brace" {
                    puts -nonewline stderr "M"
                } "^invalid command name" {
                    ::pdwindow::fatal \
                        [concat [_ "(Tcl) INVALID COMMAND NAME: "] $errorInfo "\n"]
                } default {
                    ::pdwindow::fatal \
                        [concat [_ "(Tcl) UNHANDLED ERROR: "] $errorInfo "\n"]
                }
            }
        }
    }
}