Tcl - How to get the list of all possible sub-commands/switches for a given tcl command (including user defined commands)

Question

For a given tcl user-defined command (for instance, "user_command -switch_A -switch_B") I would like to get all the possible sub-commands/switches to be used with that command as a list. Below is an example of the tcl regexp switches available: Regexp valid switches

I would like to use it to compare "implemented and public sub-commands/switches VS documented and public sub-commands/switches" for a given program.

I can get the available commands from "info commands" command, but I'm struggling to get possible valid sub-commands/switches for a given command.

Answer 1

The normal way is to use a deliberately wrong option name (such as -! ) and to catch and parse the result.

proc listOptions args {
    try {
        {*}$args -!
    } on error msg {
        if {[regexp {should be one of (.*)} $msg -> items]} {
            return [string map {{, or } { } , {}} $items]
        }
    }
    error "no option list from $args"
}

puts [listOptions chan configure stdout]

Answer 2

To find subcommands for commands that are implemented as namespace ensemble s, you can do:

set cmd "string"
set map [namespace ensemble configure $cmd -map]
dict keys $map
# => bytelength cat compare equal first index is last length map match range repeat replace reverse tolower toupper totitle trim trimleft trimright wordend wordstart