For those having source files containing data not encoded in the system encoding (and thus being not recognized correct by source), this small helper proc may help you:

---
 
 proc encsource {source_file encoding} {    
     if {![catch {open $source_file r} fid]} {
       if {![catch {fconfigure $fid -encoding $encoding} msg]} {
         set script [read $fid]
         catch {close $fid}
       } else {
         # make sure channel gets closed
         catch {close $fid}
         return -code error "unknown encoding \"$encoding\""
       }
     } else {
         # return error message similar to source cmd
         return -code error "couldn't read file \"$source_file\": no such file or directory"
     } 
     # not sure if this has to be catched as well to propagate the error code to the caller
     # to imitate the original source cmds behaviour.
     uplevel 1 $script
 }

---
 Usage:
   % encsource "test.tcl" utf-8

----
[Peter K]: I had to develop Tcl code for Windows (shudder) and used existing code on the Mac. Since I had to do a lot of transferring between Mac and cp1252, I wrote a little script to convert files and folders between all possible encodings. Here is the code (encoded in cp1252):

    #############################################################################
    # Visual Tcl v1.20 Project
    #
    #################################
    # GLOBAL VARIABLES
    #
    global Kodierung  ; set Kodierung  3
    global Kodierung1 ; set Kodierung1 cp1252
    global Kodierung2 ; set Kodierung2 macRoman
    global Eingabe ; set Eingabe ""
    global Ausgabe ; set Ausgabe ""
    global Auswahl ; set Auswahl [encoding names]
    #################################
    # USER DEFINED PROCEDURES
    #
    proc {main} {argc argv} {

    }

    #
    #
    #
    proc {Window} {args} {
    #
        set cmd [lindex $args 0]
        set name [lindex $args 1]
        set newname [lindex $args 2]
        set rest [lrange $args 3 end]
        if {$name == "" || $cmd == ""} {return}
        if {$newname == ""} {
            set newname $name
        }
        set exists [winfo exists $newname]
        switch $cmd {
            show {
                if {$exists == "1" && $name != "."} {wm deiconify $name; return}
                if {[info procs vTclWindow(pre)$name] != ""} {
                    eval "vTclWindow(pre)$name $newname $rest"
                }
                if {[info procs vTclWindow$name] != ""} {
                    eval "vTclWindow$name $newname $rest"
                }
                if {[info procs vTclWindow(post)$name] != ""} {
                    eval "vTclWindow(post)$name $newname $rest"
                }
            }
            hide    { if $exists {wm withdraw $newname; return} }
            iconify { if $exists {wm iconify $newname; return} }
            destroy { if $exists {destroy $newname; return} }
        }
    }

    #################################
    # VTCL GENERATED GUI PROCEDURES
    #

    proc vTclWindow. {base} {
        if {$base == ""} {
            set base .
        }
        ###################
        # CREATING WIDGETS
        ###################
        wm focusmodel $base passive
        wm geometry $base 1x1+25+65
        wm maxsize $base 817 594
        wm minsize $base 1 1
        wm overrideredirect $base 0
        wm resizable $base 1 1
        wm withdraw $base
        wm title $base "Wish"
        ###################
        # SETTING GEOMETRY
        ###################
    }

    proc vTclWindow.dialog {base} {
    global Kodierung
    global Kodierung1
    global Kodierung2
    global Eingabe
    global Ausgabe
    global Auswahl
    #
        if {$base == ""} {
            set base .dialog
        }
        if {[winfo exists $base]} {
            wm deiconify $base; return
        }
        ###################
        # CREATING WIDGETS
        ###################
        toplevel $base -class Toplevel -relief groove 
        wm focusmodel $base passive
        wm geometry $base 417x338+101+123
        wm maxsize $base 817 594
        wm minsize $base 1 1
        wm overrideredirect $base 0
        wm resizable $base 1 1
        wm deiconify $base
        wm title $base "Translate Encodings"
        set Verschiebung 1
    #
        frame $base.eingabe \
            -borderwidth 1 -height 30 -relief ridge -width 30 
        entry $base.eingabe.03 \
            -font -Adobe-Helvetica-Medium-R-Normal-*-*-120-*-*-*-*-*-* \
            -textvariable Eingabe -justify center -width 8 -state normal
        button $base.such1 -text "Source File:" \
            -command "Datei_lesen" -height 28
        button $base.such2 -text "Source Directory:" \
            -command "Verzeichnis_lesen" -height 28
    #
    # Das Aufklapp-MenŸ anlegen
    #
        menubutton $base.m1 \
            -menu $base.m1.sub -textvariable Kodierung1 -direction flush \
            -borderwidth 2 -indicatoron 1 -padx 8
        menu $base.m1.sub -tearoff 0
        foreach Eintrag $Auswahl {
            $base.m1.sub add radiobutton \
              -variable Kodierung1 -value $Eintrag -label $Eintrag
        }
        radiobutton $base.b0 \
            -text "MacRoman -> iso8859-1" -cursor left_ptr -anchor w \
            -variable Kodierung -value 0 \
            -command {set Kodierung1 MacRoman; set Kodierung2 iso8859-1}
        radiobutton $base.b1 \
            -text "iso8859-1 -> MacRoman" -cursor left_ptr -anchor w \
            -variable Kodierung -value 1 \
            -command {set Kodierung1 iso8859-1; set Kodierung2 MacRoman}
        radiobutton $base.b2 \
            -text "MacRoman -> cp1252" -cursor left_ptr -anchor w \
            -variable Kodierung -value 2 \
            -command {set Kodierung1 MacRoman; set Kodierung2 cp1252}
        radiobutton $base.b3 \
            -text "cp1252 -> MacRoman" -cursor left_ptr -anchor w \
            -variable Kodierung -value 3 \
            -command {set Kodierung1 cp1252; set Kodierung2 MacRoman}
        menubutton $base.m2 \
            -menu $base.m2.sub -textvariable Kodierung2 -direction flush \
            -borderwidth 2 -indicatoron 1 -padx 8
        menu $base.m2.sub -tearoff 0
        foreach Eintrag $Auswahl {
            $base.m2.sub add radiobutton \
              -variable Kodierung2 -value $Eintrag -label $Eintrag
        }
    #
        frame $base.ausgabe \
            -borderwidth 1 -height 30 -relief ridge -width 30 
        entry $base.ausgabe.03 \
            -font -Adobe-Helvetica-Medium-R-Normal-*-*-120-*-*-*-*-*-* \
            -textvariable Ausgabe -justify center -width 8 -state disabled
        button $base.such3 -text "Target File:" \
            -command "Datei_schreiben" -height 28
        button $base.such4 -text "Target Directory:" \
            -command "Verzeichnis_schreiben" -height 28
        message $base.m -width 377 \
            -text "Warning: Files will be overwritten without warning!"
        bind $base <Return> {Schreiben $Ausgabe}
    ###################
    # SETTING GEOMETRY
    ###################
        place $base.eingabe \
            -x 5 -y 45 -width 408 -height 36
        grid columnconf $base.eingabe 0 -weight 1
        grid rowconf $base.eingabe 0 -weight 1
        grid $base.eingabe.03 \
            -column 0 -row 0 -columnspan 1 -rowspan 1 -sticky nesw 
        place $base.such1 \
            -x  10 -y  16 -width 190 -height 28
        place $base.such2 \
            -x 220 -y  16 -width 190 -height 28
        place $base.m1 \
            -x  20 -y  95 -width 320 -height 29
        place $base.b0 \
            -x  20 -y  138 -anchor w
        place $base.b1 \
            -x  210 -y  138 -anchor w
        place $base.b2 \
            -x  20 -y  168 -anchor w
        place $base.b3 \
            -x  210 -y  168 -anchor w
        place $base.m2 \
            -x  20 -y 185 -width 320 -height 29
        place $base.ausgabe \
            -x   5 -y 255 -width 408 -height 36
        grid columnconf $base.ausgabe 0 -weight 1
        grid rowconf $base.ausgabe 0 -weight 1
        grid $base.ausgabe.03 \
            -column 0 -row 0 -columnspan 1 -rowspan 1 -sticky nesw 
        place $base.such3 \
            -x  10 -y 226 -width 190 -height 28
        place $base.such4 \
            -x 220 -y 226 -width 190 -height 28
        place $base.m \
            -x 20 -y 310 -anchor w
    }
      
    #
    #
    #
    proc fileDialog { w ent operation art } {
        global Namen
      #   Type names        Extension(s)  Mac File Type(s)
      #
      #---------------------------------------------------------
      set types {
        {"All files"        *               }
        {"Text files"       {}          TEXT}
        {"Text files"       {.txt}          }
      }
      if {$operation == "open"} {
            set file [tk_getOpenFile -filetypes $types -parent $w]
      } elseif {$operation == "viele"} {
            set file [tk_chooseDirectory -parent $w]
      } elseif {$operation == "save"} {
            set file [tk_getSaveFile -parent $w -initialfile $Namen]
      } else {
            set file [tk_chooseDirectory -parent $w]
      }
      if [string compare $file ""] {
            if {$art == "entry"} {
                $ent delete 0 end
                $ent insert 0 "$file"
                $ent xview end
            } else {
                set file [join [list $art Datei] {}]
            }
        }
        return $file
    }

    #
    #
    #
    proc Datei_lesen {} {
        global Eingabe
        global Namen
    #
        set Eingabe "[fileDialog .dialog .dialog.eingabe.03 open entry]"
        Einlesen
        set Namen [file tail $Eingabe]
        update
    }

    #
    #
    #
    proc Verzeichnis_lesen {} {
        global Dateiliste
    #
        set Eingabe "[fileDialog .dialog .dialog.eingabe.03 viele entry]"
        set Liste [glob -nocomplain [file join $Eingabe "*"]]
        set Dateiliste   {}
        foreach f $Liste {
            if { ![file isdirectory $f] } {
                lappend Dateiliste $f
            }
        }
    }

    #
    #
    #
    proc Datei_schreiben {} {
        global Ausgabe
        global tcl_platform
    #
        set Ausgabe "[fileDialog .dialog .dialog.ausgabe.03 save entry]"
        Schreiben
        if {$tcl_platform(platform) == "macintosh"} {
            file attributes $Ausgabe -creator "ALFA" -type "TEXT"
        }
    }

    #
    #
    #
    proc Verzeichnis_schreiben {} {
        global Eingabe
        global Ausgabe
        global Dateiliste
        global tcl_platform
    #
        set Ziel "[fileDialog .dialog .dialog.ausgabe.03 viele entry]"
        foreach f $Dateiliste {
            set Eingabe $f
            Einlesen
            set Namen [file tail $Eingabe]
            set Ausgabe [file join $Ziel $Namen]
            Schreiben
            if {$tcl_platform(platform) == "macintosh"} {
                file attributes $Ausgabe -creator "ALFA" -type "TEXT"
            }
        }
    }

    #
    #
    #
    proc Einlesen {} {
        global Kodierung1
        global Eingabe
        global Datei
    #
        encoding system $Kodierung1
    #
        if [catch {open "$Eingabe" r} fileID] {
            tk_messageBox .error -title "Fehler beim …ffnen der Datei" \
              -message "Datei $Eingabe geht nicht auf" -icon error -type ok
        } else {
            set Datei [split [read $fileID] \n]
            close $fileID
        }
    }

    #
    #
    #
    proc Schreiben {} {
        global Kodierung2
        global Ausgabe
        global Datei
    #
        encoding system $Kodierung2
    #
        if [catch {open "$Ausgabe" w} fileID] {
            tk_messageBox .error -title "Fehler beim …ffnen der Datei" \
              -message "Datei $Ausgabe geht nicht auf" -icon error -type ok
        } else {
            foreach Zeile $Datei {
                puts $fileID $Zeile
            }
            close $fileID
        }
    }

    Window show .
    Window show .dialog
    console hide
    main $argc $argv