Information about procs - info

The 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 procname
Returns a list of the names of the arguments to the procedure procname.
info body procname
Returns the body of the procedure procname.
info default procname arg varName
Returns 1 if the argument arg 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"