'''`[info] [level]`''' indicates the current [level], and can also describe the command for the current level. 



** See also **

   [uplevel]:   


** synopsis **

    :   '''`info [level]`''' ?''`number`''?



** Description **

If ''number'' is specified, `[info] levels` returns a list consisting of words of the command for the level indicated by ''number''.  A number greater than `0` indicates the level identified by that number.  `0` indicates the current level, `-1` indicates one level prior to the current level, `-2` indicates the level prior to that one, and so on.

If ''number'' is not specified, `[info] level` returns a number indicating the current [level], i.e. the level from which `[info] level` was called.  `0` is top level, and each subsequent level is incremented by 1.


** Discussion **

[MGS] 2003-09-09: '''`info level 0`''' does not return values for optional arguments (if they have not been specified):

======
proc foo {bar {baz NULL}} {
    puts "info level 0 = \[[info level 0]\]"
}

# example1
foo abc def
# example2
foo abc
======

prints:

======none
info level 0 = [foo abc def]
info level 0 = [foo abc]
======

[DGP] Correct.  `info level $level` returns the substituted list of values that make up the actual command as evaluated.  

To get values for non-specified default arguments, you have to do quite a bit more work using `[info args]` and `[info default]`.

This proc will print out info for all args in the calling proc ('''note''': does not handle being called from global level).

======
proc arginfo {} {
    set proc [lindex [info level -1] 0]
    set which [uplevel [list namespace which -command $proc]]
    puts "proc \[$which\]"
    set i -1
    foreach arg [info args $which] {
        incr i
        set value [uplevel [list set $arg]]
        if { [info default $which $arg def] } {
            puts "  arg\[$i\] \[$arg\] = \[$value\] default = \[$def\]"
        } else {
            puts "  arg\[$i\] \[$arg\] = \[$value\]"
        }
    }
}

# test code
proc test {foo {"bar baz" "BAR BAZ"}} {
    arginfo
}

test abc
test abc def

hich prints the output:

proc [::test]
    arg[0] [foo] = [abc]
    arg[1] [bar baz] = [BAR BAZ] default = [BAR BAZ]
proc [::test]
    arg[0] [foo] = [abc]
    arg[1] [bar baz] = [def] default = [BAR BAZ]
======

<<categories>> Command | Tcl syntax