Version 14 of info level

info level ?number?

If number is not specified, this command returns a number giving the stack level of the invoking procedure, or 0 if the command is invoked at top-level. If number is specified, then the result is a list consisting of the name and arguments for the procedure call at level number on the stack. If number is positive then it selects a particular stack level (1 refers to the top-most active procedure, 2 to the procedure it called, and so on); otherwise it gives a level relative to the current level (0 refers to the current procedure, -1 to its caller, and so on). See the uplevel command for more information on what stack levels mean.

See also:

• info

MGS [2003/09/09] - Note that 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:

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, 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]