if 0 {[Richard Suchenwirth] 2003-02-28 - In a [wish] on the [iPAQ], a plain [puts] raises the error
 cannot find channel named "stdout"
But as [puts] is a frequent and useful command, we want to have it working. So here�s a substitute that redirects the output to a specified text widget:
}
 proc redef_puts w {
    set ::putsw $w
    if ![llength [info command ::tcl::puts]] {
       rename puts ::tcl::puts
       proc puts args {
          set la [llength $args]
          if {$la<1 || $la>3} {
             error "usage: puts ?-nonewline? ?channel? string"
          }
          set nl \n
          if {[lindex $args 0]=="-nonewline"} {
             set nl ""
             set args [lrange $args 1 end]
          }
          if {[llength $args]==1} {
             set args [list stdout $args]
          }
          foreach {channel s} $args break
          if {$channel=="stdout" || $channel=="stderr"} {
             $::putsw insert end $s$nl
          } else {
             set cmd ::tcl::puts
             if {$nl==""} {lappend cmd -nonewline}
             lappend cmd $channel $s
             eval $cmd
          }
       }
    }
 }
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[Arts and Crafts of Tcl-Tk Programming]