--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/CSP2/CSP2_env/env-d9b9114564458d9d-741b3de822f2aaca6c6caa4325c4afce/lib/tcl8.6/init.tcl	Tue Mar 18 16:23:26 2025 -0400
@@ -0,0 +1,827 @@
+# init.tcl --
+#
+# Default system startup file for Tcl-based applications.  Defines
+# "unknown" procedure and auto-load facilities.
+#
+# Copyright (c) 1991-1993 The Regents of the University of California.
+# Copyright (c) 1994-1996 Sun Microsystems, Inc.
+# Copyright (c) 1998-1999 Scriptics Corporation.
+# Copyright (c) 2004 Kevin B. Kenny.  All rights reserved.
+#
+# See the file "license.terms" for information on usage and redistribution
+# of this file, and for a DISCLAIMER OF ALL WARRANTIES.
+#
+
+# This test intentionally written in pre-7.5 Tcl
+if {[info commands package] == ""} {
+    error "version mismatch: library\nscripts expect Tcl version 7.5b1 or later but the loaded version is\nonly [info patchlevel]"
+}
+package require -exact Tcl 8.6.13
+
+# Compute the auto path to use in this interpreter.
+# The values on the path come from several locations:
+#
+# The environment variable TCLLIBPATH
+#
+# tcl_library, which is the directory containing this init.tcl script.
+# [tclInit] (Tcl_Init()) searches around for the directory containing this
+# init.tcl and defines tcl_library to that location before sourcing it.
+#
+# The parent directory of tcl_library. Adding the parent
+# means that packages in peer directories will be found automatically.
+#
+# Also add the directory ../lib relative to the directory where the
+# executable is located.  This is meant to find binary packages for the
+# same architecture as the current executable.
+#
+# tcl_pkgPath, which is set by the platform-specific initialization routines
+#	On UNIX it is compiled in
+#       On Windows, it is not used
+#
+# (Ticket 41c9857bdd) In a safe interpreter, this file does not set
+# ::auto_path (other than to {} if it is undefined). The caller, typically
+# a Safe Base command, is responsible for setting ::auto_path.
+
+if {![info exists auto_path]} {
+    if {[info exists env(TCLLIBPATH)] && (![interp issafe])} {
+	set auto_path $env(TCLLIBPATH)
+    } else {
+	set auto_path ""
+    }
+}
+namespace eval tcl {
+    if {![interp issafe]} {
+	variable Dir
+	foreach Dir [list $::tcl_library [file dirname $::tcl_library]] {
+	    if {$Dir ni $::auto_path} {
+		lappend ::auto_path $Dir
+	    }
+	}
+	set Dir [file join [file dirname [file dirname \
+		[info nameofexecutable]]] lib]
+	if {$Dir ni $::auto_path} {
+	    lappend ::auto_path $Dir
+	}
+	if {[info exists ::tcl_pkgPath]} { catch {
+	    foreach Dir $::tcl_pkgPath {
+		if {$Dir ni $::auto_path} {
+		    lappend ::auto_path $Dir
+		}
+	    }
+	}}
+
+	variable Path [encoding dirs]
+	set Dir [file join $::tcl_library encoding]
+	if {$Dir ni $Path} {
+	    lappend Path $Dir
+	    encoding dirs $Path
+	}
+	unset Dir Path
+    }
+
+    # TIP #255 min and max functions
+    namespace eval mathfunc {
+	proc min {args} {
+	    if {![llength $args]} {
+		return -code error \
+		    "not enough arguments to math function \"min\""
+	    }
+	    set val Inf
+	    foreach arg $args {
+		# This will handle forcing the numeric value without
+		# ruining the internal type of a numeric object
+		if {[catch {expr {double($arg)}} err]} {
+		    return -code error $err
+		}
+		if {$arg < $val} {set val $arg}
+	    }
+	    return $val
+	}
+	proc max {args} {
+	    if {![llength $args]} {
+		return -code error \
+		    "not enough arguments to math function \"max\""
+	    }
+	    set val -Inf
+	    foreach arg $args {
+		# This will handle forcing the numeric value without
+		# ruining the internal type of a numeric object
+		if {[catch {expr {double($arg)}} err]} {
+		    return -code error $err
+		}
+		if {$arg > $val} {set val $arg}
+	    }
+	    return $val
+	}
+	namespace export min max
+    }
+}
+
+# Windows specific end of initialization
+
+if {(![interp issafe]) && ($tcl_platform(platform) eq "windows")} {
+    namespace eval tcl {
+	proc EnvTraceProc {lo n1 n2 op} {
+	    global env
+	    set x $env($n2)
+	    set env($lo) $x
+	    set env([string toupper $lo]) $x
+	}
+	proc InitWinEnv {} {
+	    global env tcl_platform
+	    foreach p [array names env] {
+		set u [string toupper $p]
+		if {$u ne $p} {
+		    switch -- $u {
+			COMSPEC -
+			PATH {
+			    set temp $env($p)
+			    unset env($p)
+			    set env($u) $temp
+			    trace add variable env($p) write \
+				    [namespace code [list EnvTraceProc $p]]
+			    trace add variable env($u) write \
+				    [namespace code [list EnvTraceProc $p]]
+			}
+		    }
+		}
+	    }
+	    if {![info exists env(COMSPEC)]} {
+		set env(COMSPEC) cmd.exe
+	    }
+	}
+	InitWinEnv
+    }
+}
+
+# Setup the unknown package handler
+
+
+if {[interp issafe]} {
+    package unknown {::tcl::tm::UnknownHandler ::tclPkgUnknown}
+} else {
+    # Set up search for Tcl Modules (TIP #189).
+    # and setup platform specific unknown package handlers
+    if {$tcl_platform(os) eq "Darwin"
+	    && $tcl_platform(platform) eq "unix"} {
+	package unknown {::tcl::tm::UnknownHandler \
+		{::tcl::MacOSXPkgUnknown ::tclPkgUnknown}}
+    } else {
+	package unknown {::tcl::tm::UnknownHandler ::tclPkgUnknown}
+    }
+
+    # Set up the 'clock' ensemble
+
+    namespace eval ::tcl::clock [list variable TclLibDir $::tcl_library]
+
+    proc ::tcl::initClock {} {
+	# Auto-loading stubs for 'clock.tcl'
+
+	foreach cmd {add format scan} {
+	    proc ::tcl::clock::$cmd args {
+		variable TclLibDir
+		source -encoding utf-8 [file join $TclLibDir clock.tcl]
+		return [uplevel 1 [info level 0]]
+	    }
+	}
+
+	rename ::tcl::initClock {}
+    }
+    ::tcl::initClock
+}
+
+# Conditionalize for presence of exec.
+
+if {[namespace which -command exec] eq ""} {
+
+    # Some machines do not have exec. Also, on all
+    # platforms, safe interpreters do not have exec.
+
+    set auto_noexec 1
+}
+
+# Define a log command (which can be overwitten to log errors
+# differently, specially when stderr is not available)
+
+if {[namespace which -command tclLog] eq ""} {
+    proc tclLog {string} {
+	catch {puts stderr $string}
+    }
+}
+
+# unknown --
+# This procedure is called when a Tcl command is invoked that doesn't
+# exist in the interpreter.  It takes the following steps to make the
+# command available:
+#
+#	1. See if the autoload facility can locate the command in a
+#	   Tcl script file.  If so, load it and execute it.
+#	2. If the command was invoked interactively at top-level:
+#	    (a) see if the command exists as an executable UNIX program.
+#		If so, "exec" the command.
+#	    (b) see if the command requests csh-like history substitution
+#		in one of the common forms !!, !<number>, or ^old^new.  If
+#		so, emulate csh's history substitution.
+#	    (c) see if the command is a unique abbreviation for another
+#		command.  If so, invoke the command.
+#
+# Arguments:
+# args -	A list whose elements are the words of the original
+#		command, including the command name.
+
+proc unknown args {
+    variable ::tcl::UnknownPending
+    global auto_noexec auto_noload env tcl_interactive errorInfo errorCode
+
+    if {[info exists errorInfo]} {
+	set savedErrorInfo $errorInfo
+    }
+    if {[info exists errorCode]} {
+	set savedErrorCode $errorCode
+    }
+
+    set name [lindex $args 0]
+    if {![info exists auto_noload]} {
+	#
+	# Make sure we're not trying to load the same proc twice.
+	#
+	if {[info exists UnknownPending($name)]} {
+	    return -code error "self-referential recursion\
+		    in \"unknown\" for command \"$name\""
+	}
+	set UnknownPending($name) pending
+	set ret [catch {
+		auto_load $name [uplevel 1 {::namespace current}]
+	} msg opts]
+	unset UnknownPending($name)
+	if {$ret != 0} {
+	    dict append opts -errorinfo "\n    (autoloading \"$name\")"
+	    return -options $opts $msg
+	}
+	if {![array size UnknownPending]} {
+	    unset UnknownPending
+	}
+	if {$msg} {
+	    if {[info exists savedErrorCode]} {
+		set ::errorCode $savedErrorCode
+	    } else {
+		unset -nocomplain ::errorCode
+	    }
+	    if {[info exists savedErrorInfo]} {
+		set errorInfo $savedErrorInfo
+	    } else {
+		unset -nocomplain errorInfo
+	    }
+	    set code [catch {uplevel 1 $args} msg opts]
+	    if {$code ==  1} {
+		#
+		# Compute stack trace contribution from the [uplevel].
+		# Note the dependence on how Tcl_AddErrorInfo, etc.
+		# construct the stack trace.
+		#
+		set errInfo [dict get $opts -errorinfo]
+		set errCode [dict get $opts -errorcode]
+		set cinfo $args
+		if {[string bytelength $cinfo] > 150} {
+		    set cinfo [string range $cinfo 0 150]
+		    while {[string bytelength $cinfo] > 150} {
+			set cinfo [string range $cinfo 0 end-1]
+		    }
+		    append cinfo ...
+		}
+		set tail "\n    (\"uplevel\" body line 1)\n    invoked\
+			from within\n\"uplevel 1 \$args\""
+		set expect "$msg\n    while executing\n\"$cinfo\"$tail"
+		if {$errInfo eq $expect} {
+		    #
+		    # The stack has only the eval from the expanded command
+		    # Do not generate any stack trace here.
+		    #
+		    dict unset opts -errorinfo
+		    dict incr opts -level
+		    return -options $opts $msg
+		}
+		#
+		# Stack trace is nested, trim off just the contribution
+		# from the extra "eval" of $args due to the "catch" above.
+		#
+		set last [string last $tail $errInfo]
+		if {$last + [string length $tail] != [string length $errInfo]} {
+		    # Very likely cannot happen
+		    return -options $opts $msg
+		}
+		set errInfo [string range $errInfo 0 $last-1]
+		set tail "\"$cinfo\""
+		set last [string last $tail $errInfo]
+		if {$last < 0 || $last + [string length $tail] != [string length $errInfo]} {
+		    return -code error -errorcode $errCode \
+			    -errorinfo $errInfo $msg
+		}
+		set errInfo [string range $errInfo 0 $last-1]
+		set tail "\n    invoked from within\n"
+		set last [string last $tail $errInfo]
+		if {$last + [string length $tail] == [string length $errInfo]} {
+		    return -code error -errorcode $errCode \
+			    -errorinfo [string range $errInfo 0 $last-1] $msg
+		}
+		set tail "\n    while executing\n"
+		set last [string last $tail $errInfo]
+		if {$last + [string length $tail] == [string length $errInfo]} {
+		    return -code error -errorcode $errCode \
+			    -errorinfo [string range $errInfo 0 $last-1] $msg
+		}
+		return -options $opts $msg
+	    } else {
+		dict incr opts -level
+		return -options $opts $msg
+	    }
+	}
+    }
+
+    if {([info level] == 1) && ([info script] eq "")
+	    && [info exists tcl_interactive] && $tcl_interactive} {
+	if {![info exists auto_noexec]} {
+	    set new [auto_execok $name]
+	    if {$new ne ""} {
+		set redir ""
+		if {[namespace which -command console] eq ""} {
+		    set redir ">&@stdout <@stdin"
+		}
+		uplevel 1 [list ::catch \
+			[concat exec $redir $new [lrange $args 1 end]] \
+			::tcl::UnknownResult ::tcl::UnknownOptions]
+		dict incr ::tcl::UnknownOptions -level
+		return -options $::tcl::UnknownOptions $::tcl::UnknownResult
+	    }
+	}
+	if {$name eq "!!"} {
+	    set newcmd [history event]
+	} elseif {[regexp {^!(.+)$} $name -> event]} {
+	    set newcmd [history event $event]
+	} elseif {[regexp {^\^([^^]*)\^([^^]*)\^?$} $name -> old new]} {
+	    set newcmd [history event -1]
+	    catch {regsub -all -- $old $newcmd $new newcmd}
+	}
+	if {[info exists newcmd]} {
+	    tclLog $newcmd
+	    history change $newcmd 0
+	    uplevel 1 [list ::catch $newcmd \
+		    ::tcl::UnknownResult ::tcl::UnknownOptions]
+	    dict incr ::tcl::UnknownOptions -level
+	    return -options $::tcl::UnknownOptions $::tcl::UnknownResult
+	}
+
+	set ret [catch {set candidates [info commands $name*]} msg]
+	if {$name eq "::"} {
+	    set name ""
+	}
+	if {$ret != 0} {
+	    dict append opts -errorinfo \
+		    "\n    (expanding command prefix \"$name\" in unknown)"
+	    return -options $opts $msg
+	}
+	# Filter out bogus matches when $name contained
+	# a glob-special char [Bug 946952]
+	if {$name eq ""} {
+	    # Handle empty $name separately due to strangeness
+	    # in [string first] (See RFE 1243354)
+	    set cmds $candidates
+	} else {
+	    set cmds [list]
+	    foreach x $candidates {
+		if {[string first $name $x] == 0} {
+		    lappend cmds $x
+		}
+	    }
+	}
+	if {[llength $cmds] == 1} {
+	    uplevel 1 [list ::catch [lreplace $args 0 0 [lindex $cmds 0]] \
+		    ::tcl::UnknownResult ::tcl::UnknownOptions]
+	    dict incr ::tcl::UnknownOptions -level
+	    return -options $::tcl::UnknownOptions $::tcl::UnknownResult
+	}
+	if {[llength $cmds]} {
+	    return -code error "ambiguous command name \"$name\": [lsort $cmds]"
+	}
+    }
+    return -code error -errorcode [list TCL LOOKUP COMMAND $name] \
+	"invalid command name \"$name\""
+}
+
+# auto_load --
+# Checks a collection of library directories to see if a procedure
+# is defined in one of them.  If so, it sources the appropriate
+# library file to create the procedure.  Returns 1 if it successfully
+# loaded the procedure, 0 otherwise.
+#
+# Arguments:
+# cmd -			Name of the command to find and load.
+# namespace (optional)  The namespace where the command is being used - must be
+#                       a canonical namespace as returned [namespace current]
+#                       for instance. If not given, namespace current is used.
+
+proc auto_load {cmd {namespace {}}} {
+    global auto_index auto_path
+
+    if {$namespace eq ""} {
+	set namespace [uplevel 1 [list ::namespace current]]
+    }
+    set nameList [auto_qualify $cmd $namespace]
+    # workaround non canonical auto_index entries that might be around
+    # from older auto_mkindex versions
+    lappend nameList $cmd
+    foreach name $nameList {
+	if {[info exists auto_index($name)]} {
+	    namespace eval :: $auto_index($name)
+	    # There's a couple of ways to look for a command of a given
+	    # name.  One is to use
+	    #    info commands $name
+	    # Unfortunately, if the name has glob-magic chars in it like *
+	    # or [], it may not match.  For our purposes here, a better
+	    # route is to use
+	    #    namespace which -command $name
+	    if {[namespace which -command $name] ne ""} {
+		return 1
+	    }
+	}
+    }
+    if {![info exists auto_path]} {
+	return 0
+    }
+
+    if {![auto_load_index]} {
+	return 0
+    }
+    foreach name $nameList {
+	if {[info exists auto_index($name)]} {
+	    namespace eval :: $auto_index($name)
+	    if {[namespace which -command $name] ne ""} {
+		return 1
+	    }
+	}
+    }
+    return 0
+}
+
+# auto_load_index --
+# Loads the contents of tclIndex files on the auto_path directory
+# list.  This is usually invoked within auto_load to load the index
+# of available commands.  Returns 1 if the index is loaded, and 0 if
+# the index is already loaded and up to date.
+#
+# Arguments:
+# None.
+
+proc auto_load_index {} {
+    variable ::tcl::auto_oldpath
+    global auto_index auto_path
+
+    if {[info exists auto_oldpath] && ($auto_oldpath eq $auto_path)} {
+	return 0
+    }
+    set auto_oldpath $auto_path
+
+    # Check if we are a safe interpreter. In that case, we support only
+    # newer format tclIndex files.
+
+    set issafe [interp issafe]
+    for {set i [expr {[llength $auto_path] - 1}]} {$i >= 0} {incr i -1} {
+	set dir [lindex $auto_path $i]
+	set f ""
+	if {$issafe} {
+	    catch {source [file join $dir tclIndex]}
+	} elseif {[catch {set f [open [file join $dir tclIndex]]}]} {
+	    continue
+	} else {
+	    set error [catch {
+		fconfigure $f -eofchar "\032 {}"
+		set id [gets $f]
+		if {$id eq "# Tcl autoload index file, version 2.0"} {
+		    eval [read $f]
+		} elseif {$id eq "# Tcl autoload index file: each line identifies a Tcl"} {
+		    while {[gets $f line] >= 0} {
+			if {([string index $line 0] eq "#") \
+				|| ([llength $line] != 2)} {
+			    continue
+			}
+			set name [lindex $line 0]
+			set auto_index($name) \
+				"source [file join $dir [lindex $line 1]]"
+		    }
+		} else {
+		    error "[file join $dir tclIndex] isn't a proper Tcl index file"
+		}
+	    } msg opts]
+	    if {$f ne ""} {
+		close $f
+	    }
+	    if {$error} {
+		return -options $opts $msg
+	    }
+	}
+    }
+    return 1
+}
+
+# auto_qualify --
+#
+# Compute a fully qualified names list for use in the auto_index array.
+# For historical reasons, commands in the global namespace do not have leading
+# :: in the index key. The list has two elements when the command name is
+# relative (no leading ::) and the namespace is not the global one. Otherwise
+# only one name is returned (and searched in the auto_index).
+#
+# Arguments -
+# cmd		The command name. Can be any name accepted for command
+#               invocations (Like "foo::::bar").
+# namespace	The namespace where the command is being used - must be
+#               a canonical namespace as returned by [namespace current]
+#               for instance.
+
+proc auto_qualify {cmd namespace} {
+
+    # count separators and clean them up
+    # (making sure that foo:::::bar will be treated as foo::bar)
+    set n [regsub -all {::+} $cmd :: cmd]
+
+    # Ignore namespace if the name starts with ::
+    # Handle special case of only leading ::
+
+    # Before each return case we give an example of which category it is
+    # with the following form :
+    # (inputCmd, inputNameSpace) -> output
+
+    if {[string match ::* $cmd]} {
+	if {$n > 1} {
+	    # (::foo::bar , *) -> ::foo::bar
+	    return [list $cmd]
+	} else {
+	    # (::global , *) -> global
+	    return [list [string range $cmd 2 end]]
+	}
+    }
+
+    # Potentially returning 2 elements to try  :
+    # (if the current namespace is not the global one)
+
+    if {$n == 0} {
+	if {$namespace eq "::"} {
+	    # (nocolons , ::) -> nocolons
+	    return [list $cmd]
+	} else {
+	    # (nocolons , ::sub) -> ::sub::nocolons nocolons
+	    return [list ${namespace}::$cmd $cmd]
+	}
+    } elseif {$namespace eq "::"} {
+	#  (foo::bar , ::) -> ::foo::bar
+	return [list ::$cmd]
+    } else {
+	# (foo::bar , ::sub) -> ::sub::foo::bar ::foo::bar
+	return [list ${namespace}::$cmd ::$cmd]
+    }
+}
+
+# auto_import --
+#
+# Invoked during "namespace import" to make see if the imported commands
+# reside in an autoloaded library.  If so, the commands are loaded so
+# that they will be available for the import links.  If not, then this
+# procedure does nothing.
+#
+# Arguments -
+# pattern	The pattern of commands being imported (like "foo::*")
+#               a canonical namespace as returned by [namespace current]
+
+proc auto_import {pattern} {
+    global auto_index
+
+    # If no namespace is specified, this will be an error case
+
+    if {![string match *::* $pattern]} {
+	return
+    }
+
+    set ns [uplevel 1 [list ::namespace current]]
+    set patternList [auto_qualify $pattern $ns]
+
+    auto_load_index
+
+    foreach pattern $patternList {
+        foreach name [array names auto_index $pattern] {
+            if {([namespace which -command $name] eq "")
+		    && ([namespace qualifiers $pattern] eq [namespace qualifiers $name])} {
+                namespace eval :: $auto_index($name)
+            }
+        }
+    }
+}
+
+# auto_execok --
+#
+# Returns string that indicates name of program to execute if
+# name corresponds to a shell builtin or an executable in the
+# Windows search path, or "" otherwise.  Builds an associative
+# array auto_execs that caches information about previous checks,
+# for speed.
+#
+# Arguments:
+# name -			Name of a command.
+
+if {$tcl_platform(platform) eq "windows"} {
+# Windows version.
+#
+# Note that file executable doesn't work under Windows, so we have to
+# look for files with .exe, .com, or .bat extensions.  Also, the path
+# may be in the Path or PATH environment variables, and path
+# components are separated with semicolons, not colons as under Unix.
+#
+proc auto_execok name {
+    global auto_execs env tcl_platform
+
+    if {[info exists auto_execs($name)]} {
+	return $auto_execs($name)
+    }
+    set auto_execs($name) ""
+
+    set shellBuiltins [list assoc cls copy date del dir echo erase exit ftype \
+	    md mkdir mklink move rd ren rename rmdir start time type ver vol]
+    if {[info exists env(PATHEXT)]} {
+	# Add an initial ; to have the {} extension check first.
+	set execExtensions [split ";$env(PATHEXT)" ";"]
+    } else {
+	set execExtensions [list {} .com .exe .bat .cmd]
+    }
+
+    if {[string tolower $name] in $shellBuiltins} {
+	# When this is command.com for some reason on Win2K, Tcl won't
+	# exec it unless the case is right, which this corrects.  COMSPEC
+	# may not point to a real file, so do the check.
+	set cmd $env(COMSPEC)
+	if {[file exists $cmd]} {
+	    set cmd [file attributes $cmd -shortname]
+	}
+	return [set auto_execs($name) [list $cmd /c $name]]
+    }
+
+    if {[llength [file split $name]] != 1} {
+	foreach ext $execExtensions {
+	    set file ${name}${ext}
+	    if {[file exists $file] && ![file isdirectory $file]} {
+		return [set auto_execs($name) [list $file]]
+	    }
+	}
+	return ""
+    }
+
+    set path "[file dirname [info nameof]];.;"
+    if {[info exists env(SystemRoot)]} {
+	set windir $env(SystemRoot)
+    } elseif {[info exists env(WINDIR)]} {
+	set windir $env(WINDIR)
+    }
+    if {[info exists windir]} {
+	if {$tcl_platform(os) eq "Windows NT"} {
+	    append path "$windir/system32;"
+	}
+	append path "$windir/system;$windir;"
+    }
+
+    foreach var {PATH Path path} {
+	if {[info exists env($var)]} {
+	    append path ";$env($var)"
+	}
+    }
+
+    foreach ext $execExtensions {
+	unset -nocomplain checked
+	foreach dir [split $path {;}] {
+	    # Skip already checked directories
+	    if {[info exists checked($dir)] || ($dir eq "")} {
+		continue
+	    }
+	    set checked($dir) {}
+	    set file [file join $dir ${name}${ext}]
+	    if {[file exists $file] && ![file isdirectory $file]} {
+		return [set auto_execs($name) [list $file]]
+	    }
+	}
+    }
+    return ""
+}
+
+} else {
+# Unix version.
+#
+proc auto_execok name {
+    global auto_execs env
+
+    if {[info exists auto_execs($name)]} {
+	return $auto_execs($name)
+    }
+    set auto_execs($name) ""
+    if {[llength [file split $name]] != 1} {
+	if {[file executable $name] && ![file isdirectory $name]} {
+	    set auto_execs($name) [list $name]
+	}
+	return $auto_execs($name)
+    }
+    foreach dir [split $env(PATH) :] {
+	if {$dir eq ""} {
+	    set dir .
+	}
+	set file [file join $dir $name]
+	if {[file executable $file] && ![file isdirectory $file]} {
+	    set auto_execs($name) [list $file]
+	    return $auto_execs($name)
+	}
+    }
+    return ""
+}
+
+}
+
+# ::tcl::CopyDirectory --
+#
+# This procedure is called by Tcl's core when attempts to call the
+# filesystem's copydirectory function fail.  The semantics of the call
+# are that 'dest' does not yet exist, i.e. dest should become the exact
+# image of src.  If dest does exist, we throw an error.
+#
+# Note that making changes to this procedure can change the results
+# of running Tcl's tests.
+#
+# Arguments:
+# action -              "renaming" or "copying"
+# src -			source directory
+# dest -		destination directory
+proc tcl::CopyDirectory {action src dest} {
+    set nsrc [file normalize $src]
+    set ndest [file normalize $dest]
+
+    if {$action eq "renaming"} {
+	# Can't rename volumes.  We could give a more precise
+	# error message here, but that would break the test suite.
+	if {$nsrc in [file volumes]} {
+	    return -code error "error $action \"$src\" to\
+	      \"$dest\": trying to rename a volume or move a directory\
+	      into itself"
+	}
+    }
+    if {[file exists $dest]} {
+	if {$nsrc eq $ndest} {
+	    return -code error "error $action \"$src\" to\
+	      \"$dest\": trying to rename a volume or move a directory\
+	      into itself"
+	}
+	if {$action eq "copying"} {
+	    # We used to throw an error here, but, looking more closely
+	    # at the core copy code in tclFCmd.c, if the destination
+	    # exists, then we should only call this function if -force
+	    # is true, which means we just want to over-write.  So,
+	    # the following code is now commented out.
+	    #
+	    # return -code error "error $action \"$src\" to\
+	    # \"$dest\": file already exists"
+	} else {
+	    # Depending on the platform, and on the current
+	    # working directory, the directories '.', '..'
+	    # can be returned in various combinations.  Anyway,
+	    # if any other file is returned, we must signal an error.
+	    set existing [glob -nocomplain -directory $dest * .*]
+	    lappend existing {*}[glob -nocomplain -directory $dest \
+		    -type hidden * .*]
+	    foreach s $existing {
+		if {[file tail $s] ni {. ..}} {
+		    return -code error "error $action \"$src\" to\
+		      \"$dest\": file already exists"
+		}
+	    }
+	}
+    } else {
+	if {[string first $nsrc $ndest] >= 0} {
+	    set srclen [expr {[llength [file split $nsrc]] - 1}]
+	    set ndest [lindex [file split $ndest] $srclen]
+	    if {$ndest eq [file tail $nsrc]} {
+		return -code error "error $action \"$src\" to\
+		  \"$dest\": trying to rename a volume or move a directory\
+		  into itself"
+	    }
+	}
+	file mkdir $dest
+    }
+    # Have to be careful to capture both visible and hidden files.
+    # We will also be more generous to the file system and not
+    # assume the hidden and non-hidden lists are non-overlapping.
+    #
+    # On Unix 'hidden' files begin with '.'.  On other platforms
+    # or filesystems hidden files may have other interpretations.
+    set filelist [concat [glob -nocomplain -directory $src *] \
+      [glob -nocomplain -directory $src -types hidden *]]
+
+    foreach s [lsort -unique $filelist] {
+	if {[file tail $s] ni {. ..}} {
+	    file copy -force -- $s [file join $dest [file tail $s]]
+	}
+    }
+    return
+}