info command includes a set of
subcommands that will provide all the info you could want about a
proc. These subcommands will return the body of a proc, the
arguments to the proc, and the value of any default arguments. These subcommands can be used to:
Info commands that return information about a proc
info args
procnameprocname.info body
procnameprocname.info default procname arg
varNamearg in
procedure procName has a default, and sets
varName to the default. Otherwise, returns
0.
proc demo {argument1 {default "DefaultValue"} } {
puts "This is a demo proc. It is being called with $argument1 and $default"
#
# We can use [info level] to find out if a value was given for
# the optional argument "default" ...
#
puts "Actual call: [info level [info level]]"
}
puts "The args for demo are: [info args demo]\n"
puts "The body for demo is: [info body demo]\n"
set arglist [info args demo]
foreach arg $arglist {
if {[info default demo $arg defaultval]} {
puts "$arg has a default value of $defaultval"
} else {
puts "$arg has no default"
}
}