summaryrefslogtreecommitdiffstats
path: root/library/init.tcl
blob: 397ed41ad162069dc49e158b61f35240035b2bf4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
# init.tcl --
#
# Default system startup file for Tcl-based applications.  Defines
# "unknown" procedure and auto-load facilities.
#
# SCCS: %Z% $Id: init.tcl,v 1.3 1998/07/02 17:52:32 escoffon Exp $ 
#
# Copyright (c) 1991-1993 The Regents of the University of California.
# Copyright (c) 1994-1996 Sun Microsystems, Inc.
#
# See the file "license.terms" for information on usage and redistribution
# of this file, and for a DISCLAIMER OF ALL WARRANTIES.
#

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 8.0

# Compute the auto path to use in this interpreter.
# (auto_path could be already set, in safe interps for instance)

if {![info exists auto_path]} {
    if {[catch {set auto_path $env(TCLLIBPATH)}]} {
	set auto_path ""
    }
}
if {[lsearch -exact $auto_path [info library]] < 0} {
    lappend auto_path [info library]
}
catch {
    foreach __dir $tcl_pkgPath {
	if {[lsearch -exact $auto_path $__dir] < 0} {
	    lappend auto_path $__dir
	}
    }
    unset __dir
}

# Windows specific end of initialization

if {(![interp issafe]) && ($tcl_platform(platform) == "windows")} {
    namespace eval tcl {
	proc envTraceProc {lo n1 n2 op} {
	    set x $::env($n2)
	    set ::env($lo) $x
	    set ::env([string toupper $lo]) $x
	}
    }
    foreach p [array names env] {
	set u [string toupper $p]
	if {$u != $p} {
	    switch -- $u {
		COMSPEC -
		PATH {
		    if {![info exists env($u)]} {
			set env($u) $env($p)
		    }
		    trace variable env($p) w [list tcl::envTraceProc $p]
		    trace variable env($u) w [list tcl::envTraceProc $p]
		}
	    }
	}
    }
    if {![info exists env(COMSPEC)]} {
	if {$tcl_platform(os) == {Windows NT}} {
	    set env(COMSPEC) cmd.exe
	} else {
	    set env(COMSPEC) command.com
	}
    }
}


# Setup the unknown package handler

package unknown tclPkgUnknown

# Conditionalize for presence of exec.

if {[info commands exec] == ""} {

    # Some machines, such as the Macintosh, do not have exec. Also, on all
    # platforms, safe interpreters do not have exec.

    set auto_noexec 1
}
set errorCode ""
set errorInfo ""

# Define a log command (which can be overwitten to log errors
# differently, specially when stderr is not available)

if {[info commands tclLog] == ""} {
    proc tclLog {string} {
	catch {puts stderr $string}
    }
}

# The procs defined in this file that have a leading space
# are 'hidden' from auto_mkindex because they are not
# auto-loadable.


# 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 {
    global auto_noexec auto_noload env unknown_pending tcl_interactive
    global errorCode errorInfo

    # Save the values of errorCode and errorInfo variables, since they
    # may get modified if caught errors occur below.  The variables will
    # be restored just before re-executing the missing command.

    set savedErrorCode $errorCode
    set savedErrorInfo $errorInfo
    set name [lindex $args 0]
    if {![info exists auto_noload]} {
	#
	# Make sure we're not trying to load the same proc twice.
	#
	if {[info exists unknown_pending($name)]} {
	    return -code error "self-referential recursion in \"unknown\" for command \"$name\"";
	}
	set unknown_pending($name) pending;
	set ret [catch {auto_load $name [uplevel 1 {namespace current}]} msg]
	unset unknown_pending($name);
	if {$ret != 0} {
	    return -code $ret -errorcode $errorCode \
		"error while autoloading \"$name\": $msg"
	}
	if {![array size unknown_pending]} {
	    unset unknown_pending
	}
	if {$msg} {
	    set errorCode $savedErrorCode
	    set errorInfo $savedErrorInfo
	    set code [catch {uplevel 1 $args} msg]
	    if {$code ==  1} {
		#
		# Strip the last five lines off the error stack (they're
		# from the "uplevel" command).
		#

		set new [split $errorInfo \n]
		set new [join [lrange $new 0 [expr {[llength $new] - 6}]] \n]
		return -code error -errorcode $errorCode \
			-errorinfo $new $msg
	    } else {
		return -code $code $msg
	    }
	}
    }

    if {([info level] == 1) && ([info script] == "") \
	    && [info exists tcl_interactive] && $tcl_interactive} {
	if {![info exists auto_noexec]} {
	    set new [auto_execok $name]
	    if {$new != ""} {
		set errorCode $savedErrorCode
		set errorInfo $savedErrorInfo
		set redir ""
		if {[info commands console] == ""} {
		    set redir ">&@stdout <@stdin"
		}
		return [uplevel exec $redir $new [lrange $args 1 end]]
	    }
	}
	set errorCode $savedErrorCode
	set errorInfo $savedErrorInfo
	if {$name == "!!"} {
	    set newcmd [history event]
	} elseif {[regexp {^!(.+)$} $name dummy event]} {
	    set newcmd [history event $event]
	} elseif {[regexp {^\^([^^]*)\^([^^]*)\^?$} $name dummy old new]} {
	    set newcmd [history event -1]
	    catch {regsub -all -- $old $newcmd $new newcmd}
	}
	if {[info exists newcmd]} {
	    tclLog $newcmd
	    history change $newcmd 0
	    return [uplevel $newcmd]
	}

	set ret [catch {set cmds [info commands $name*]} msg]
	if {[string compare $name "::"] == 0} {
	    set name ""
	}
	if {$ret != 0} {
	    return -code $ret -errorcode $errorCode \
		"error in unknown while checking if \"$name\" is a unique command abbreviation: $msg"
	}
	if {[llength $cmds] == 1} {
	    return [uplevel [lreplace $args 0 0 $cmds]]
	}
	if {[llength $cmds] != 0} {
	    if {$name == ""} {
		return -code error "empty command name \"\""
	    } else {
		return -code error \
			"ambiguous command name \"$name\": [lsort $cmds]"
	    }
	}
    }
    return -code error "invalid command name \"$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_oldpath auto_path env errorInfo errorCode

    if {[string length $namespace] == 0} {
	set namespace [uplevel {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)]} {
	    uplevel #0 $auto_index($name)
	    return [expr {[info commands $name] != ""}]
	}
    }
    if {![info exists auto_path]} {
	return 0
    }
    if {[info exists auto_oldpath]} {
	if {$auto_oldpath == $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 {
		set id [gets $f]
		if {$id == "# Tcl autoload index file, version 2.0"} {
		    eval [read $f]
		} elseif {$id == \
		    "# Tcl autoload index file: each line identifies a Tcl"} {
		    while {[gets $f line] >= 0} {
			if {([string index $line 0] == "#")
				|| ([llength $line] != 2)} {
			    continue
			}
			set name [lindex $line 0]
			set auto_index($name) \
			    "source [file join $dir [lindex $line 1]]"
		    }
		} else {
		    error \
		      "[file join $dir tclIndex] isn't a proper Tcl index file"
		}
	    } msg]
	    if {$f != ""} {
		close $f
	    }
	    if {$error} {
		error $msg $errorInfo $errorCode
	    }
	}
    }
    foreach name $nameList {
	if {[info exists auto_index($name)]} {
	    uplevel #0 $auto_index($name)
	    if {[info commands $name] != ""} {
		return 1
	    }
	}
    }
    return 0
}

# 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 {[regexp {^::(.*)$} $cmd x tail]} {
	if {$n > 1} {
	    # ( ::foo::bar , * ) -> ::foo::bar
	    return [list $cmd]
	} else {
	    # ( ::global , * ) -> global
	    return [list $tail]
	}
    }
    
    # Potentially returning 2 elements to try  :
    # (if the current namespace is not the global one)

    if {$n == 0} {
	if {[string compare $namespace ::] == 0} {
	    # ( nocolons , :: ) -> nocolons
	    return [list $cmd]
	} else {
	    # ( nocolons , ::sub ) -> ::sub::nocolons nocolons
	    return [list ${namespace}::$cmd $cmd]
	}
    } else {
	if {[string compare $namespace ::] == 0} {
	    #  ( foo::bar , :: ) -> ::foo::bar
	    return [list ::$cmd]
	} else {
	    # ( foo::bar , ::sub ) -> ::sub::foo::bar ::foo::bar
	    return [list ${namespace}::$cmd ::$cmd]
	}
    }
}

if {[string compare $tcl_platform(platform) windows] == 0} {

# 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.

# Windows version.
#
# Note that info 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) ""

    if {[lsearch -exact {cls copy date del erase dir echo mkdir md rename 
	    ren rmdir rd time type ver vol} $name] != -1} {
	return [set auto_execs($name) [list $env(COMSPEC) /c $name]]
    }

    if {[llength [file split $name]] != 1} {
	foreach ext {{} .com .exe .bat} {
	    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(WINDIR)]} {
	set windir $env(WINDIR) 
    }
    if {[info exists windir]} {
	if {$tcl_platform(os) == "Windows NT"} {
	    append path "$windir/system32;"
	}
	append path "$windir/system;$windir;"
    }

    if {[info exists env(PATH)]} {
	append path $env(PATH)
    }

    foreach dir [split $path {;}] {
	if {$dir == ""} {
	    set dir .
	}
	foreach ext {{} .com .exe .bat} {
	    set file [file join $dir ${name}${ext}]
	    if {[file exists $file] && ![file isdirectory $file]} {
		return [set auto_execs($name) [list $file]]
	    }
	}
    }
    return ""
}

} else {

# auto_execok --
#
# Returns string that indicates name of program to execute if 
# name corresponds to an executable in the path. Builds an associative 
# array auto_execs that caches information about previous checks, 
# for speed.
#
# Arguments: 
# name -			Name of a command.

# 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 == ""} {
	    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 ""
}

}
# auto_reset --
# Destroy all cached information for auto-loading and auto-execution,
# so that the information gets recomputed the next time it's needed.
# Also delete any procedures that are listed in the auto-load index
# except those defined in this file.
#
# Arguments: 
# None.

proc auto_reset {} {
    global auto_execs auto_index auto_oldpath
    foreach p [info procs] {
	if {[info exists auto_index($p)] && ![string match auto_* $p]
		&& ([lsearch -exact {unknown pkg_mkIndex tclPkgSetup
			tclMacPkgSearch tclPkgUnknown} $p] < 0)} {
	    rename $p {}
	}
    }
    catch {unset auto_execs}
    catch {unset auto_index}
    catch {unset auto_oldpath}
}

# auto_mkindex --
# Regenerate a tclIndex file from Tcl source files.  Takes as argument
# the name of the directory in which the tclIndex file is to be placed,
# followed by any number of glob patterns to use in that directory to
# locate all of the relevant files. It does not parse or source the file
# so the generated index will not contain the appropriate namespace qualifiers
# if you don't explicitly specify it.
#
# Arguments: 
# dir -			Name of the directory in which to create an index.
# args -		Any number of additional arguments giving the
#			names of files within dir.  If no additional
#			are given auto_mkindex will look for *.tcl.

proc auto_mkindex {dir args} {
    global errorCode errorInfo
    set oldDir [pwd]
    cd $dir
    set dir [pwd]
    append index "# Tcl autoload index file, version 2.0\n"
    append index "# This file is generated by the \"auto_mkindex\" command\n"
    append index "# and sourced to set up indexing information for one or\n"
    append index "# more commands.  Typically each line is a command that\n"
    append index "# sets an element in the auto_index array, where the\n"
    append index "# element name is the name of a command and the value is\n"
    append index "# a script that loads the command.\n\n"
    if {$args == ""} {
	set args *.tcl
    }
    foreach file [eval glob $args] {
	set f ""
	set error [catch {
	    set f [open $file]
	    while {[gets $f line] >= 0} {
		if {[regexp {^proc[ 	]+([^ 	]*)} $line match procName]} {
		    set procName [lindex [auto_qualify $procName "::"] 0]
		    append index "set [list auto_index($procName)]"
		    append index " \[list source \[file join \$dir [list $file]\]\]\n"
		}
	    }
	    close $f
	} msg]
	if {$error} {
	    set code $errorCode
	    set info $errorInfo
	    catch {close $f}
	    cd $oldDir
	    error $msg $info $code
	}
    }
    set f ""
    set error [catch {
	set f [open tclIndex w]
	puts $f $index nonewline
	close $f
	cd $oldDir
    } msg]
    if {$error} {
	set code $errorCode
	set info $errorInfo
	catch {close $f}
	cd $oldDir
	error $msg $info $code
    }
}

# pkg_mkIndex --
# This procedure creates a package index in a given directory.  The
# package index consists of a "pkgIndex.tcl" file whose contents are
# a Tcl script that sets up package information with "package require"
# commands.  The commands describe all of the packages defined by the
# files given as arguments.
#
# Arguments:
# -direct		(optional) If this flag is present, the generated
#			code in pkgMkIndex.tcl will cause the package to be
#			loaded when "package require" is executed, rather
#			than lazily when the first reference to an exported
#			procedure in the package is made.
# -nopkgrequire		(optional) If this flag is present, "package require"
#			commands are ignored. This flag is useful in some
#			situations, for example when there is a circularity
#			in package requires (package a requires package b,
#			which in turns requires package a).
# dir -			Name of the directory in which to create the index.
# args -		Any number of additional arguments, each giving
#			a glob pattern that matches the names of one or
#			more shared libraries or Tcl script files in
#			dir.

proc pkg_mkIndex {args} {
    global errorCode errorInfo
    set usage {"pkg_mkIndex ?-nopkgrequire? ?-direct? dir ?pattern ...?"};

    set argCount [llength $args]
    if {$argCount < 1} {
	return -code error "wrong # args: should be\n$usage"
    }

    set more ""
    set direct 0
    set noPkgRequire 0
    for {set idx 0} {$idx < $argCount} {incr idx} {
	set flag [lindex $args $idx]
	switch -glob -- $flag {
	    -- {
		# done with the flags
		incr idx
		break
	    }

	    -direct {
		set direct 1
		append more " -direct"
	    }

	    -nopkgrequire {
		set noPkgRequire 1
		append more " -nopkgrequire"
	    }

	    -* {
		return -code error "unknown flag $flag: should be\n$usage"
	    }

	    default {
		# done with the flags
		break
	    }
	}
    }

    set dir [lindex $args $idx]
    set patternList [lrange $args [expr $idx + 1] end]
    if {[llength $patternList] == 0} {
	set patternList [list "*.tcl" "*[info sharedlibextension]"]
    }

    append index "# Tcl package index file, version 1.1\n"
    append index "# This file is generated by the \"pkg_mkIndex$more\" command\n"
    append index "# and sourced either when an application starts up or\n"
    append index "# by a \"package unknown\" script.  It invokes the\n"
    append index "# \"package ifneeded\" command to set up package-related\n"
    append index "# information so that packages will be loaded automatically\n"
    append index "# in response to \"package require\" commands.  When this\n"
    append index "# script is sourced, the variable \$dir must contain the\n"
    append index "# full path name of this file's directory.\n"
    set oldDir [pwd]
    cd $dir

    # In order to support building of index files from scratch, we make
    # repeated passes on the files to index, until either all have been
    # indexed, or we can no longer make any headway.

    foreach file [eval glob $patternList] {
	set toProcess($file) 1
    }

    while {[array size toProcess] > 0} {
	set processed 0

	foreach file [array names toProcess] {
	    # For each file, figure out what commands and packages it provides.
	    # To do this, create a child interpreter, load the file into the
	    # interpreter, and get a list of the new commands and packages
	    # that are defined. The interpeter uses a special version of
	    # tclPkgSetup to force loading of required packages at require
	    # time rather than lazily, so that we can keep track of commands
	    # and packages that are defined indirectly rather than from the
	    # file itself.

	    set c [interp create]

	    # Load into the child all packages currently loaded in the parent
	    # interpreter, in case the extension depends on some of them.

	    foreach pkg [info loaded] {
		if {[lindex $pkg 1] == "Tk"} {
		    $c eval {set argv {-geometry +0+0}}
		}
		load [lindex $pkg 0] [lindex $pkg 1] $c
	    }





















		    }
		    proc __dummy args {}
		    package unknown __dummy
		}
	    } else {
		$c eval {
		    rename package __package_orig
		    proc package {what args} {
			switch -- $what {
			    require {
				eval __package_orig require $args

				# a package that was required needs to be
				# placed in the list of packages to ignore.
				# tclPkgSetup is unable to do it, so do it
				# here.

				set ::__ignorePkgs([lindex $args 0]) 1
			    }

			    provide {
				# if package provide is called at level 1 and
				# with two arguments, then this package is
				# being provided by one of the files we are
				# indexing, and therefore we need to add it
				# to the list of packages to write out.
				# We need to do this check because otherwise
				# packages that are spread over multiple
				# files are indexed only by their first file
				# loaded.
				# Note that packages that this cannot catch
				# packages that are implemented by a
				# combination of TCL files and DLLs

				if {([info level] == 1) \
					&& ([llength $args] == 2)} {
				    lappend ::__providedPkgs [lindex $args 0]
				}

				eval __package_orig provide $args
			    }

			    default { eval __package_orig {$what} $args }
			}
		    }
		}
	    }

	    $c eval [list set __file $file]
	    $c eval [list set __direct $direct]
	    if {[catch {
		$c eval {
		    set __doingWhat "loading or sourcing"

		    # override the tclPkgSetup procedure (which is called by
		    # package ifneeded statements from pkgIndex.tcl) to force
		    # loads of packages, and also keep track of
		    # packages/namespaces/commands that the load generated

		    proc tclPkgSetup {dir pkg version files} {
			# remember the current set of packages and commands,
			# so that we can add any that were defined by the
			# package files to the list of packages and commands
			# to ignore

			foreach __p [package names] {
			    set __localIgnorePkgs($__p) 1
			}
			foreach __ns [__pkgGetAllNamespaces] {
			    set __localIgnoreNs($__ns) 1
			}
			foreach __cmd [info commands] {
			    set __localIgnoreCmds($__cmd) 1
			}
			
			# load the files that make up the package

			package provide $pkg $version
			foreach __fileInfo $files {
			    set __f [lindex $__fileInfo 0]
			    set __type [lindex $__fileInfo 1]
			    if {$__type == "load"} {
				load [file join $dir $__f] $pkg
			    } else {
				source [file join $dir $__f]
			    }
			}

			# packages and commands that were defined by these
			# files are to be ignored.

			foreach __p [package names] {
			    if {[info exists __localIgnorePkgs($__p)] == 0} {
				set ::__ignorePkgs($__p) 1
			    }
			}
			foreach __ns [__pkgGetAllNamespaces] {
			    if {([info exists __localIgnoreNs($__ns)] == 0) \
				&& ([info exists ::__ignoreNs($__ns)] == 0)} {
				namespace import ${__ns}::*
				set ::__ignoreNs($__ns) 1
			    }
			}
			foreach __cmd [info commands] {
			    if {[info exists __localIgnoreCmds($__cmd)] == 0} {
				lappend ::__ignoreCmds $__cmd
			    }
			}
		    }

		    # we need to track command defined by each package even in
		    # the -direct case, because they are needed internally by
		    # the "partial pkgIndex.tcl" step above.

		    proc __pkgGetAllNamespaces {{root {}}} {
			set __list $root
			foreach __ns [namespace children $root] {
			    eval lappend __list [__pkgGetAllNamespaces $__ns]
			}
			return $__list
		    }
		    set ::__ignoreCmds [info commands]

		    # initialize the list of packages to ignore; these are
		    # packages that are present before the script/dll is loaded

		    set ::__ignorePkgs(Tcl) 1
		    set ::__ignorePkgs(Tk) 1
		    foreach __pkg [package names] {
			set ::__ignorePkgs($__pkg) 1
		    }

		    # before marking the original commands, import all the
		    # namespaces that may have been loaded from the parent;
		    # these namespaces and their commands are to be ignored

		    foreach __ns [__pkgGetAllNamespaces] {
			set ::__ignoreNs($__ns) 1
			namespace import ${__ns}::*
		    }

		    set dir ""		;# in case file is pkgIndex.tcl

		    # Try to load the file if it has the shared library
		    # extension, otherwise source it.  It's important not to
		    # try to load files that aren't shared libraries, because
		    # on some systems (like SunOS) the loader will abort the
		    # whole application when it gets an error.

		    set __pkgs {}
		    set __providedPkgs {}
		    if {[string compare [file extension $__file] \
			    [info sharedlibextension]] == 0} {

			# The "file join ." command below is necessary.
			# Without it, if the file name has no \'s and we're
			# on UNIX, the load command will invoke the
			# LD_LIBRARY_PATH search mechanism, which could cause
			# the wrong file to be used.

			set __doingWhat loading
			load [file join . $__file]
			set __type load
		    } else {
			set __doingWhat sourcing
			source $__file
			set __type source
		    }

		    # Using __ variable names to avoid potential namespaces
		    # clash, even here in post processing because the
		    # loaded package could have set up traces,...

		    foreach __ns [__pkgGetAllNamespaces] {
			if {[info exists ::__ignoreNs($__ns)] == 0} {
			    namespace import ${__ns}::*
			}
		    }
		    foreach __i [info commands] {
			set __cmds($__i) 1
		    }
		    foreach __i $::__ignoreCmds {
			catch {unset __cmds($__i)}
		    }
		    foreach __i [array names __cmds] {
			# reverse engineer which namespace a command comes from
			set __absolute [namespace origin $__i]
			if {[string compare $__i $__absolute] != 0} {
			    set __cmds($__absolute) 1
			    unset __cmds($__i)
			}
		    }

		    foreach __i $::__providedPkgs {
			lappend __pkgs [list $__i [package provide $__i]]
			set __ignorePkgs($__i) 1
		    }
		    foreach __i [package names] {
			if {([string compare [package provide $__i] ""] != 0) \
				&& ([info exists ::__ignorePkgs($__i)] == 0)} {
			    lappend __pkgs [list $__i [package provide $__i]]
			}
		    }
		}
	    } msg] == 1} {
		set what [$c eval set __doingWhat]
		tclLog "warning: error while $what $file: $msg"
	    } else {
		set type [$c eval set __type]
		set cmds [lsort [$c eval array names __cmds]]
		set pkgs [$c eval set __pkgs]
		if {[llength $pkgs] > 1} {
		    tclLog "warning: \"$file\" provides more than one package ($pkgs)"
		}
		foreach pkg $pkgs {
		    # cmds is empty/not used in the direct case
		    lappend files($pkg) [list $file $type $cmds]
		}

		incr processed
		unset toProcess($file)
	    }

	    tclLog "error while loading or sourcing $file: $msg"
	}

	if {$processed == 0} {
	    tclLog "this iteration could not process any files: giving up here"
	    break
	}
    }

    foreach pkg [lsort [array names files]] {
	append index "\npackage ifneeded $pkg "
	if {$direct} {
	    set cmdList {}
	    foreach elem $files($pkg) {
		set file [lindex $elem 0]
		set type [lindex $elem 1]
		lappend cmdList "\[list $type \[file join \$dir\
			[list $file]\]\]"
	    }
	    append index [join $cmdList "\\n"]
	} else {
	    append index "\[list tclPkgSetup \$dir [lrange $pkg 0 0]\
		    [lrange $pkg 1 1] [list $files($pkg)]\]"
	}
    }
    set f [open pkgIndex.tcl w]
    puts $f $index
    close $f
    cd $oldDir
}

# tclPkgSetup --
# This is a utility procedure use by pkgIndex.tcl files.  It is invoked
# as part of a "package ifneeded" script.  It calls "package provide"
# to indicate that a package is available, then sets entries in the
# auto_index array so that the package's files will be auto-loaded when
# the commands are used.
#
# Arguments:
# dir -			Directory containing all the files for this package.
# pkg -			Name of the package (no version number).
# version -		Version number for the package, such as 2.1.3.
# files -		List of files that constitute the package.  Each
#			element is a sub-list with three elements.  The first
#			is the name of a file relative to $dir, the second is
#			"load" or "source", indicating whether the file is a
#			loadable binary or a script to source, and the third
#			is a list of commands defined by this file.

proc tclPkgSetup {dir pkg version files} {
    global auto_index

    package provide $pkg $version
    foreach fileInfo $files {
	set f [lindex $fileInfo 0]
	set type [lindex $fileInfo 1]
	foreach cmd [lindex $fileInfo 2] {
	    if {$type == "load"} {
		set auto_index($cmd) [list load [file join $dir $f] $pkg]
	    } else {
		set auto_index($cmd) [list source [file join $dir $f]]
	    } 
	}
    }
}

# tclMacPkgSearch --
# The procedure is used on the Macintosh to search a given directory for files
# with a TEXT resource named "pkgIndex".  If it exists it is sourced in to the
# interpreter to setup the package database.

proc tclMacPkgSearch {dir} {
    foreach x [glob -nocomplain [file join $dir *.shlb]] {
	if {[file isfile $x]} {
	    set res [resource open $x]
	    foreach y [resource list TEXT $res] {
		if {$y == "pkgIndex"} {source -rsrc pkgIndex}
	    }
	    catch {resource close $res}
	}
    }
}

# tclPkgUnknown --
# This procedure provides the default for the "package unknown" function.
# It is invoked when a package that's needed can't be found.  It scans
# the auto_path directories and their immediate children looking for
# pkgIndex.tcl files and sources any such files that are found to setup
# the package database.  (On the Macintosh we also search for pkgIndex
# TEXT resources in all files.)
#
# Arguments:
# name -		Name of desired package.  Not used.
# version -		Version of desired package.  Not used.
# exact -		Either "-exact" or omitted.  Not used.

proc tclPkgUnknown {name version {exact {}}} {
    global auto_path tcl_platform env

    if {![info exists auto_path]} {
	return
    }
    for {set i [expr {[llength $auto_path] - 1}]} {$i >= 0} {incr i -1} {
	# we can't use glob in safe interps, so enclose the following
	# in a catch statement
	catch {
	    foreach file [glob -nocomplain [file join [lindex $auto_path $i] \
		    * pkgIndex.tcl]] {
		set dir [file dirname $file]
		if {[catch {source $file} msg]} {
		    tclLog "error reading package index file $file: $msg"
		}
	    }
        }
	set dir [lindex $auto_path $i]
	set file [file join $dir pkgIndex.tcl]
	# safe interps usually don't have "file readable", nor stderr channel
	if {[interp issafe] || [file readable $file]} {
	    if {[catch {source $file} msg] && ![interp issafe]}  {
		tclLog "error reading package index file $file: $msg"
	    }
	}
	# On the Macintosh we also look in the resource fork 
	# of shared libraries
	# We can't use tclMacPkgSearch in safe interps because it uses glob
	if {(![interp issafe]) && ($tcl_platform(platform) == "macintosh")} {
	    set dir [lindex $auto_path $i]
	    tclMacPkgSearch $dir
	    foreach x [glob -nocomplain [file join $dir *]] {
		if {[file isdirectory $x]} {
		    set dir $x
		    tclMacPkgSearch $dir
		}
	    }
	}
    }
}