aboutsummaryrefslogtreecommitdiffstats
path: root/lib/stdlib/src/c.erl
blob: 38a36c168a647897c1509a128aaafef97a30e5bc (plain) (blame)
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
%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1996-2016. All Rights Reserved.
%%
%% Licensed under the Apache License, Version 2.0 (the "License");
%% you may not use this file except in compliance with the License.
%% You may obtain a copy of the License at
%%
%%     http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing, software
%% distributed under the License is distributed on an "AS IS" BASIS,
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%% See the License for the specific language governing permissions and
%% limitations under the License.
%%
%% %CopyrightEnd%
%%
-module(c).

%% Utilities to use from shell.

%% Avoid warning for local function error/2 clashing with autoimported BIF.
-compile({no_auto_import,[error/2]}).
-export([help/0,lc/1,c/1,c/2,c/3,nc/1,nc/2, nl/1,l/1,i/0,i/1,ni/0,
         y/1, y/2,
	 lc_batch/0, lc_batch/1,
	 i/3,pid/3,m/0,m/1,mm/0,lm/0,
	 bt/1, q/0,
	 erlangrc/0,erlangrc/1,bi/1, flush/0, regs/0, uptime/0,
	 nregs/0,pwd/0,ls/0,ls/1,cd/1,memory/1,memory/0, xm/1]).

-export([display_info/1]).
-export([appcall/4]).

-import(lists, [reverse/1,flatten/1,sublist/3,sort/1,keysort/2,
		max/1,min/1,foreach/2,foldl/3,flatmap/2]).
-import(io, [format/1, format/2]).

%%-----------------------------------------------------------------------

-spec help() -> 'ok'.

help() ->
    io:put_chars(<<"bt(Pid)    -- stack backtrace for a process\n"
		   "c(Mod)     -- compile and load module or file <Mod>\n"
		   "cd(Dir)    -- change working directory\n"
		   "flush()    -- flush any messages sent to the shell\n"
		   "help()     -- help info\n"
		   "i()        -- information about the system\n"
		   "ni()       -- information about the networked system\n"
		   "i(X,Y,Z)   -- information about pid <X,Y,Z>\n"
		   "l(Module)  -- load or reload module\n"
		   "lm()       -- load all modified modules\n"
		   "lc([File]) -- compile a list of Erlang modules\n"
		   "ls()       -- list files in the current directory\n"
		   "ls(Dir)    -- list files in directory <Dir>\n"
		   "m()        -- which modules are loaded\n"
		   "m(Mod)     -- information about module <Mod>\n"
		   "mm()       -- list all modified modules\n"
		   "memory()   -- memory allocation information\n"
		   "memory(T)  -- memory allocation information of type <T>\n"
		   "nc(File)   -- compile and load code in <File> on all nodes\n"
		   "nl(Module) -- load module on all nodes\n"
		   "pid(X,Y,Z) -- convert X,Y,Z to a Pid\n"
		   "pwd()      -- print working directory\n"
		   "q()        -- quit - shorthand for init:stop()\n"
		   "regs()     -- information about registered processes\n"
		   "nregs()    -- information about all registered processes\n"
		   "uptime()   -- print node uptime\n"
		   "xm(M)      -- cross reference check a module\n"
		   "y(File)    -- generate a Yecc parser\n">>).

%% c(Module)
%%  Compile a module/file.

-spec c(Module) -> {'ok', ModuleName} | 'error' when
      Module :: file:name(),
      ModuleName :: module().

c(Module) -> c(Module, []).

-spec c(Module, Options) -> {'ok', ModuleName} | 'error' when
      Module :: file:name(),
      Options :: [compile:option()],
      ModuleName :: module().

c(Module, Opts) when is_atom(Module) ->
    %% either a module name or a source file name (possibly without
    %% suffix); if such a source file exists, it is used to compile from
    %% scratch with the given options, otherwise look for an object file
    Suffix = case filename:extension(Module) of
                 "" -> src_suffix(Opts);
                 S -> S
             end,
    SrcFile = filename:rootname(Module, Suffix) ++ Suffix,
    case filelib:is_file(SrcFile) of
        true ->
            compile_and_load(SrcFile, Opts);
        false ->
            c(Module, Opts, fun (_) -> true end)
    end;
c(Module, Opts) ->
    %% we never interpret a string as a module name, only as a file
    compile_and_load(Module, Opts).

%% This tries to find an existing object file and use its compile_info and
%% source path to recompile the module, overwriting the old object file.
%% The Filter parameter is applied to the old compile options

-spec c(Module, Options, Filter) -> {'ok', ModuleName} | 'error' when
      Module :: atom(),
      Options :: [compile:option()],
      Filter :: fun ((compile:option()) -> boolean()),
      ModuleName :: module().

c(Module, Options, Filter) when is_atom(Module) ->
    case find_beam(Module) of
        BeamFile when is_list(BeamFile) ->
            c(Module, Options, Filter, BeamFile);
        Error ->
            {error, Error}
    end.

c(Module, Options, Filter, BeamFile) ->
    case compile_info(Module, BeamFile) of
        Info when is_list(Info) ->
            case find_source(BeamFile, Info) of
                SrcFile when is_list(SrcFile) ->
                    c(SrcFile, Options, Filter, BeamFile, Info);
                Error ->
                    Error
            end;
        Error ->
            Error
    end.

c(SrcFile, NewOpts, Filter, BeamFile, Info) ->
    %% Filter old options; also remove options that will be replaced.
    %% Write new beam over old beam unless other outdir is specified.
    F = fun (Opt) -> not is_outdir_opt(Opt) andalso Filter(Opt) end,
    Options = (NewOpts ++ [{outdir,filename:dirname(BeamFile)}]
               ++ lists:filter(F, old_options(Info))),
    format("Recompiling ~s\n", [SrcFile]),
    safe_recompile(SrcFile, Options, BeamFile).

old_options(Info) ->
    case lists:keyfind(options, 1, Info) of
        {options, Opts} -> Opts;
        false -> []
    end.

%% prefer the source path in the compile info if the file exists,
%% otherwise do a standard source search relative to the beam file
find_source(BeamFile, Info) ->
    case lists:keyfind(source, 1, Info) of
        {source, SrcFile} ->
            case filelib:is_file(SrcFile) of
                true -> SrcFile;
                false -> find_source(BeamFile)
            end;
        _ ->
            find_source(BeamFile)
    end.

find_source(BeamFile) ->
    case filelib:find_source(BeamFile) of
        {ok, SrcFile} -> SrcFile;
        _ -> {error, no_source}
    end.

%% find the beam file for a module, preferring the path reported by code:which()
%% if it still exists, or otherwise by searching the code path
find_beam(Module) when is_atom(Module) ->
    case code:which(Module) of
        Beam when is_list(Beam), Beam =/= "" ->
            case erlang:module_loaded(Module) of
                false ->
                    Beam;  % code:which/1 found this in the path
                true ->
                    case filelib:is_file(Beam) of
                        true -> Beam;
                        false -> find_beam_1(Module)  % file moved?
                    end
            end;
        Other when Other =:= ""; Other =:= cover_compiled ->
            %% module is loaded but not compiled directly from source
            find_beam_1(Module);
        Error ->
            Error
    end.

find_beam_1(Module) ->
    File = atom_to_list(Module) ++ code:objfile_extension(),
    case code:where_is_file(File) of
        Beam when is_list(Beam) ->
            Beam;
        Error ->
            Error
    end.

%% get the compile_info for a module
%% -will report the info for the module in memory, if loaded
%% -will try to find and examine the beam file if not in memory
%% -will not cause a module to become loaded by accident
compile_info(Module, Beam) when is_atom(Module) ->
    case erlang:module_loaded(Module) of
        true ->
            %% getting the compile info for a loaded module should normally
            %% work, but return an empty info list if it fails
            try erlang:get_module_info(Module, compile)
            catch _:_ -> []
            end;
        false ->
            case beam_lib:chunks(Beam, [compile_info]) of
                {ok, {_Module, [{compile_info, Info}]}} ->
                    Info;
                Error ->
                    Error
            end
    end.

%% compile module, backing up any existing target file and restoring the
%% old version if compilation fails (this should only be used when we have
%% an old beam file that we want to preserve)
safe_recompile(File, Options, BeamFile) ->
    %% Note that it's possible that because of options such as 'to_asm',
    %% the compiler might not actually write a new beam file at all
    Backup = BeamFile ++ ".bak",
    case file:rename(BeamFile, Backup) of
        Status when Status =:= ok; Status =:= {error,enoent} ->
            case compile_and_load(File, Options) of
                {ok, _} = Result ->
                    _ = if Status =:= ok -> file:delete(Backup);
                           true -> ok
                        end,
                    Result;
                Error ->
                    _ = if Status =:= ok -> file:rename(Backup, BeamFile);
                           true -> ok
                        end,
                    Error
            end;
        Error ->
            Error
    end.

%% Compile the file and load the resulting object code (if any).
%% Automatically ensures that there is an outdir option, by default the
%% directory of File, and that a 'from' option will be passed to match the
%% actual source suffix if needed (unless already specified).
compile_and_load(File, Opts0) when is_list(Opts0) ->
    Opts = [report_errors, report_warnings
            | ensure_from(filename:extension(File),
                          ensure_outdir(filename:dirname(File), Opts0))],
    case compile:file(File, Opts) of
	{ok,Mod} ->				%Listing file.
	    purge_and_load(Mod, File, Opts);
	{ok,Mod,_Ws} ->				%Warnings maybe turned on.
	    purge_and_load(Mod, File, Opts);
	Other ->				%Errors go here
	    Other
    end;
compile_and_load(File, Opt) ->
    compile_and_load(File, [Opt]).

ensure_from(Suffix, Opts0) ->
    case lists:partition(fun is_from_opt/1, Opts0++from_opt(Suffix)) of
        {[Opt|_], Opts} -> [Opt | Opts];
        {[], Opts} -> Opts
    end.

ensure_outdir(Dir, Opts0) ->
    {[Opt|_], Opts} = lists:partition(fun is_outdir_opt/1,
                                      Opts0++[{outdir,Dir}]),
    [Opt | Opts].

is_outdir_opt({outdir, _}) -> true;
is_outdir_opt(_) -> false.

is_from_opt(from_core) -> true;
is_from_opt(from_asm) -> true;
is_from_opt(from_beam) -> true;
is_from_opt(_) -> false.

from_opt(".core") -> [from_core];
from_opt(".S")    -> [from_asm];
from_opt(".beam") -> [from_beam];
from_opt(_)       -> [].

%%% Obtain the 'outdir' option from the argument. Return "." if no
%%% such option was given.
-spec outdir([compile:option()]) -> file:filename().

outdir([]) ->
    ".";
outdir([Opt|Rest]) ->
    case Opt of
	{outdir, D} ->
	    D;
	_ ->
	    outdir(Rest)
    end.

%% mimic how suffix is selected in compile:file().
src_suffix([from_core|_]) -> ".core";
src_suffix([from_asm|_])  -> ".S";
src_suffix([from_beam|_]) -> ".beam";
src_suffix([_|Opts]) -> src_suffix(Opts);
src_suffix([]) -> ".erl".

%%% We have compiled File with options Opts. Find out where the
%%% output file went and load it, purging any old version.
purge_and_load(Mod, File, Opts) ->
    Dir = outdir(Opts),
    Base = filename:basename(File, src_suffix(Opts)),
    OutFile = filename:join(Dir, Base),
    case compile:output_generated(Opts) of
	true ->
	    case atom_to_list(Mod) of
		Base ->
		    code:purge(Mod),
                    %% Note that load_abs() adds the object file suffix
		    case code:load_abs(OutFile, Mod) of
                        {error, _R}=Error -> Error;
                        _ -> {ok, Mod}
                    end;
		_OtherMod ->
		    format("** Module name '~p' does not match file name '~tp' **~n",
			   [Mod,File]),
		    {error, badfile}
	    end;
	false ->
	    format("** Warning: No object file created - nothing loaded **~n", []),
	    ok
    end.

%% Compile a list of modules
%% enables the nice unix shell cmd
%% erl -s c lc f1 f2 f3 @d c1=v1 @c2 @i IDir @o ODir -s erlang halt
%% to compile files f1.erl , f2.erl ....... from a unix shell
%% with constant c2 defined, c1=v1 (v1 must be a term!), include dir
%% IDir, outdir ODir.

-spec lc(Files) -> 'ok' | 'error' when
      Files :: [File :: erl_compile:cmd_line_arg()].

lc(Args) ->
    case catch split(Args, [], []) of
	error -> error;
	{Opts, Files} ->
	    COpts = [report_errors, report_warnings | reverse(Opts)],
	    foreach(fun(File) -> compile:file(File, COpts) end, reverse(Files))
    end.

%%% lc_batch/1 works like lc/1, but halts afterwards, with appropriate
%%% exit code. This is meant to be called by "erl -compile".

-spec lc_batch() -> no_return().

lc_batch() ->
    io:format("Error: no files to compile~n"),
    halt(1).

-spec lc_batch([erl_compile:cmd_line_arg()]) -> no_return().

lc_batch(Args) ->
    try split(Args, [], []) of
	{Opts, Files} ->
	    COpts = [report_errors, report_warnings | reverse(Opts)],
            Res = [compile:file(File, COpts) || File <- reverse(Files)],
	    case lists:member(error, Res) of
		true ->
		    halt(1);
		false ->
		    halt(0)
	    end
    catch
	throw:error -> halt(1)
    end.

split(['@i', Dir | T], Opts, Files) ->
    split(T, [{i, atom_to_list(Dir)} | Opts], Files);
split(['@o', Dir | T], Opts, Files) ->
    split(T, [{outdir, atom_to_list(Dir)} | Opts], Files);
split(['@d', Def | T], Opts, Files) ->
    split(T, [split_def(atom_to_list(Def), []) | Opts], Files);
split([File | T], Opts, Files) ->
    split(T, Opts, [File | Files]);
split([], Opts, Files) ->
    {Opts, Files}.

split_def([$= | T], Res) -> {d, list_to_atom(reverse(Res)),make_term(T)};
split_def([H | T], Res) -> split_def(T, [H | Res]);
split_def([], Res) -> {d, list_to_atom(reverse(Res))}.

make_term(Str) ->
    case erl_scan:string(Str) of
	{ok, Tokens, _} ->
	    case erl_parse:parse_term(Tokens ++ [{dot, 1}]) of
		{ok, Term} -> Term;
		{error, {_,_,Reason}} ->
		    io:format("~ts: ~ts~n", [Reason, Str]),
		    throw(error)
	    end;
	{error, {_,_,Reason}, _} ->
	    io:format("~ts: ~ts~n", [Reason, Str]),
	    throw(error)
    end.

-spec nc(File) -> {'ok', Module} | 'error' when
      File :: file:name(),
      Module :: module().

nc(File) -> nc(File, []).

-spec nc(File, Options) -> {'ok', Module} | 'error' when
      File :: file:name(),
      Options :: [Option] | Option,
      Option:: compile:option(),
      Module :: module().

nc(File, Opts0) when is_list(Opts0) ->
    Opts = Opts0 ++ [report_errors, report_warnings],
    case compile:file(File, Opts) of
	{ok,Mod} ->
	    Dir = outdir(Opts),
	    Obj = filename:basename(File, ".erl") ++ code:objfile_extension(),
	    Fname = filename:join(Dir, Obj),
	    case file:read_file(Fname) of
		{ok,Bin} ->
		    rpc:eval_everywhere(code,load_binary,[Mod,Fname,Bin]),
		    {ok,Mod};
		Other ->
		    Other
	    end;
	Other ->                                %Errors go here
	    Other
    end;
nc(File, Opt) when is_atom(Opt) -> 
    nc(File, [Opt]).

%% l(Mod)
%%  Reload module Mod from file of same name
-spec l(Module) -> code:load_ret() when
      Module :: module().

l(Mod) ->
    code:purge(Mod),
    code:load_file(Mod).

%% Network version of l/1
-spec nl(Module) -> abcast | error when
      Module :: module().

nl(Mod) ->
    case code:get_object_code(Mod) of
	{_Module, Bin, Fname} ->
            rpc:eval_everywhere(code, load_binary, [Mod, Fname, Bin]);
	Other ->
	    Other
    end.

-spec i() -> 'ok'.

i() -> i(processes()).

-spec ni() -> 'ok'.

ni() -> i(all_procs()).

-spec i([pid()]) -> 'ok'.

i(Ps) ->
    i(Ps, length(Ps)).

-spec i([pid()], non_neg_integer()) -> 'ok'.

i(Ps, N) when N =< 100 ->
    iformat("Pid", "Initial Call", "Heap", "Reds",
	    "Msgs"),
    iformat("Registered", "Current Function", "Stack", "",
	    ""),
    {R,M,H,S} = foldl(fun(Pid, {R0,M0,H0,S0}) ->
			      {A,B,C,D} = display_info(Pid),
			      {R0+A,M0+B,H0+C,S0+D}
		      end, {0,0,0,0}, Ps),
    iformat("Total", "", w(H), w(R), w(M)),
    iformat("", "", w(S), "", "");
i(Ps, N) ->
    iformat("Pid", "Initial Call", "Heap", "Reds",
	    "Msgs"),
    iformat("Registered", "Current Function", "Stack", "",
	    ""),
    paged_i(Ps, {0,0,0,0}, N, 50).

paged_i([], {R,M,H,S}, _, _) ->
    iformat("Total", "", w(H), w(R), w(M)),
    iformat("", "", w(S), "", "");
paged_i(Ps, Acc, N, Page) ->
    {Pids, Rest, N1} =
	if N > Page ->
		{L1,L2} = lists:split(Page, Ps),
		{L1,L2,N-Page};
	   true ->
		{Ps, [], 0}
	end,
    NewAcc = foldl(fun(Pid, {R,M,H,S}) ->
			   {A,B,C,D} = display_info(Pid),
			   {R+A,M+B,H+C,S+D}
		   end, Acc, Pids),
    case Rest of
	[_|_] ->
	    choice(fun() -> paged_i(Rest, NewAcc, N1, Page) end);
	[] ->
	    paged_i([], NewAcc, 0, Page)
    end.

choice(F) ->
    case get_line('(c)ontinue (q)uit -->', "c\n") of
	"c\n" ->
	    F();
	"q\n" ->
	    quit;
	_ ->
	    choice(F)
    end.

get_line(P, Default) ->
    case line_string(io:get_line(P)) of
	"\n" ->
	    Default;
	L ->
	    L
    end.

%% If the standard input is set to binary mode
%% convert it to a list so we can properly match.
line_string(Binary) when is_binary(Binary) -> unicode:characters_to_list(Binary);
line_string(Other) -> Other.

mfa_string(Fun) when is_function(Fun) ->
    {module,M} = erlang:fun_info(Fun, module),
    {name,F} = erlang:fun_info(Fun, name),
    {arity,A} = erlang:fun_info(Fun, arity),
    mfa_string({M,F,A});
mfa_string({M,F,A}) ->
    io_lib:format("~w:~w/~w", [M,F,A]);
mfa_string(X) ->
    w(X).

display_info(Pid) ->
    case pinfo(Pid) of
	undefined -> {0,0,0,0};
	Info ->
	    Call = initial_call(Info),
	    Curr = case fetch(current_function, Info) of
		       {Mod,F,Args} when is_list(Args) ->
			   {Mod,F,length(Args)};
		       Other ->
			   Other
		   end,
	    Reds = fetch(reductions, Info),
	    LM = length(fetch(messages, Info)),
	    HS = fetch(heap_size, Info),
	    SS = fetch(stack_size, Info),
	    iformat(w(Pid), mfa_string(Call),
		    w(HS),
		    w(Reds), w(LM)),
	    iformat(case fetch(registered_name, Info) of
			0 -> "";
			X -> w(X)
		    end,
		    mfa_string(Curr),
		    w(SS),
		    "",
		    ""),
	    {Reds, LM, HS, SS}
    end.

%% We have to do some assumptions about the initial call.
%% If the initial call is proc_lib:init_p/3,5 we can find more information
%% calling the function proc_lib:initial_call/1.

initial_call(Info)  ->
    case fetch(initial_call, Info) of
	{proc_lib, init_p, _} ->
	    proc_lib:translate_initial_call(Info);
	ICall ->
	    ICall
    end.

iformat(A1, A2, A3, A4, A5) ->
    format("~-21s ~-33s ~8s ~8s ~4s~n", [A1,A2,A3,A4,A5]).

all_procs() ->
    case is_alive() of
	true -> flatmap(fun (N) -> rpc:call(N,erlang,processes,[]) end,
			[node()|nodes()]);
	false -> processes()
    end.

pinfo(Pid) ->
    case is_alive() of
	true -> rpc:call(node(Pid), erlang, process_info, [Pid]);
	false -> process_info(Pid)
    end.

fetch(Key, Info) ->
    case lists:keyfind(Key, 1, Info) of
	{_, Val} -> Val;
	false -> 0
    end.

-spec pid(X, Y, Z) -> pid() when
      X :: non_neg_integer(),
      Y :: non_neg_integer(),
      Z :: non_neg_integer().

pid(X, Y, Z) ->
    list_to_pid("<" ++ integer_to_list(X) ++ "." ++
		integer_to_list(Y) ++ "." ++
		integer_to_list(Z) ++ ">").

-spec i(X, Y, Z) -> [{atom(), term()}] when
      X :: non_neg_integer(),
      Y :: non_neg_integer(),
      Z :: non_neg_integer().

i(X, Y, Z) -> pinfo(pid(X, Y, Z)).

-spec q() -> no_return().

q() ->
    init:stop().

-spec bt(Pid) -> 'ok' | 'undefined' when
      Pid :: pid().

bt(Pid) ->
    case catch erlang:process_display(Pid, backtrace) of
	{'EXIT', _} ->
	    undefined;
	_ ->
	    ok
    end.

-spec m() -> 'ok'.

m() ->
    mformat("Module", "File"),
    foreach(fun ({Mod,File}) -> mformat(Mod, File) end, sort(code:all_loaded())).

mformat(A1, A2) ->
    format("~-20s  ~ts\n", [A1,A2]).

-spec mm() -> [module()].

mm() ->
    code:modified_modules().

-spec lm() -> [code:load_ret()].

lm() ->
    [l(M) || M <- mm()].

%% erlangrc(Home)
%%  Try to run a ".erlang" file, first in the current directory
%%  else in home directory.

erlangrc() ->
    case init:get_argument(home) of
	{ok,[[Home]]} ->
	    erlangrc([Home]);
	_ ->
	    f_p_e(["."], ".erlang")
    end.

erlangrc([Home]) ->
    f_p_e([".",Home], ".erlang").

error(Fmt, Args) ->
    error_logger:error_msg(Fmt, Args).

f_p_e(P, F) ->
    case file:path_eval(P, F) of
	{error, enoent} = Enoent ->
	    Enoent;
	{error, E={Line, _Mod, _Term}} ->
	    error("file:path_eval(~tp,~tp): error on line ~p: ~ts~n",
		  [P, F, Line, file:format_error(E)]),
	    ok;
	{error, E} ->
	    error("file:path_eval(~tp,~tp): ~ts~n",
		  [P, F, file:format_error(E)]),
	    ok;
	Other ->
	    Other
    end.

bi(I) ->
    case erlang:system_info(I) of
	X when is_binary(X) -> io:put_chars(binary_to_list(X));
	X when is_list(X) -> io:put_chars(X);
	X -> format("~w", [X])
    end.

%%
%% Short and nice form of module info
%%
-spec m(Module) -> 'ok' when
      Module :: module().

m(M) ->
    L = M:module_info(),
    {exports,E} = lists:keyfind(exports, 1, L),
    Time = get_compile_time(L),
    COpts = get_compile_options(L),
    format("Module: ~w~n", [M]),
    print_md5(L),
    format("Compiled: "),
    print_time(Time),
    print_object_file(M),
    format("Compiler options:  ~p~n", [COpts]),
    format("Exports: ~n",[]), print_exports(keysort(1, E)).

print_object_file(Mod) ->
    case code:is_loaded(Mod) of
	{file,File} ->
	    format("Object file: ~ts\n", [File]);
	_ ->
	    ignore
    end.

print_md5(L) ->
    case lists:keyfind(md5, 1, L) of
        {md5,<<MD5:128>>} -> io:format("MD5: ~.16b~n",[MD5]);
        _ -> ok
    end.

get_compile_time(L) ->
    case get_compile_info(L, time) of
	{ok,Val} -> Val;
	error -> notime
    end.

get_compile_options(L) ->
    case get_compile_info(L, options) of
	{ok,Val} -> Val;
	error -> []
    end.

get_compile_info(L, Tag) ->
    case lists:keyfind(compile, 1, L) of
	{compile, I} ->
	    case lists:keyfind(Tag, 1, I) of
		{Tag, Val} -> {ok,Val};
		false -> error
	    end;
	false -> error
    end.

print_exports(X) when length(X) > 16 ->
    split_print_exports(X);
print_exports([]) -> ok;
print_exports([{F, A} |Tail]) ->
    format("         ~w/~w~n",[F, A]),
    print_exports(Tail).

split_print_exports(L) ->
    Len = length(L),
    Mid = Len div 2,
    L1 = sublist(L, 1, Mid),
    L2 = sublist(L, Mid +1, Len - Mid + 1),
    split_print_exports(L1, L2).

split_print_exports([], [{F, A}|T]) ->
    Str = " ",
    format("~-30s~w/~w~n", [Str, F, A]),
    split_print_exports([], T);
split_print_exports([{F1, A1}|T1], [{F2, A2} | T2]) ->
    Str = flatten(io_lib:format("~w/~w", [F1, A1])),
    format("~-30s~w/~w~n", [Str, F2, A2]),
    split_print_exports(T1, T2);
split_print_exports([], []) -> ok.

print_time({Year,Month,Day,Hour,Min,_Secs}) ->
    format("~s ~w ~w, ", [month(Month),Day,Year]),
    format("~.2.0w:~.2.0w~n", [Hour,Min]);
print_time(notime) ->
    format("No compile time info available~n",[]).

month(1) -> "January";
month(2) -> "February";
month(3) -> "March";
month(4) -> "April";
month(5) -> "May";
month(6) -> "June";
month(7) -> "July";
month(8) -> "August";
month(9) -> "September";
month(10) -> "October";
month(11) -> "November";
month(12) -> "December".

%% Just because we can't eval receive statements...
-spec flush() -> 'ok'.

flush() ->
    receive
	X ->
            case lists:keyfind(encoding, 1, io:getopts()) of
                {encoding,unicode} ->
                    format("Shell got ~tp~n",[X]);
                _ ->
                    format("Shell got ~p~n",[X])
            end,
	    flush()
    after 0 ->
	    ok
    end.

%% Print formatted info about all registered names in the system
-spec nregs() -> 'ok'.

nregs() ->
    foreach(fun (N) -> print_node_regs(N) end, all_regs()).

-spec regs() -> 'ok'.

regs() ->
    print_node_regs({node(),registered()}).

all_regs() ->
    case is_alive() of
        true -> [{N,rpc:call(N, erlang, registered, [])} ||
                    N <- [node()|nodes()]];
	false -> [{node(),registered()}]
    end.

print_node_regs({N, List}) when is_list(List) ->
    {Pids,Ports,_Dead} = pids_and_ports(N, sort(List), [], [], []),
    %% print process info
    format("~n** Registered procs on node ~w **~n",[N]),
    procformat("Name", "Pid", "Initial Call", "Reds", "Msgs"),
    foreach(fun({Name,PI,Pid}) -> procline(Name, PI, Pid) end, Pids),
    %% print port info
    format("~n** Registered ports on node ~w **~n",[N]),
    portformat("Name", "Id", "Command"),
    foreach(fun({Name,PI,Id}) -> portline(Name, PI, Id) end, Ports).

pids_and_ports(_, [], Pids, Ports, Dead) ->
    {reverse(Pids),reverse(Ports),reverse(Dead)};

pids_and_ports(Node, [Name|Names], Pids, Ports, Dead) ->
    case pwhereis(Node, Name) of
	Pid when is_pid(Pid) ->
	    pids_and_ports(Node, Names, [{Name,pinfo(Pid),Pid}|Pids],
			   Ports, Dead);
	Id when is_port(Id) ->
	    pids_and_ports(Node, Names, Pids, 
			   [{Name,portinfo(Id),Id}|Ports], Dead);
	undefined ->
	    pids_and_ports(Node, Names, Pids, Ports, [Name|Dead])
    end.

pwhereis(Node, Name) ->
    case is_alive() of
	true -> rpc:call(Node, erlang, whereis, [Name]);
	false -> whereis(Name)
    end.

portinfo(Id) ->
    case is_alive() of
	true ->  [ rpc:call(node(Id), erlang, port_info, [Id,name]) ];
	false -> [ erlang:port_info(Id, name) ]
    end.

procline(Name, Info, Pid) ->
    Call = initial_call(Info),
    Reds  = fetch(reductions, Info),
    LM = length(fetch(messages, Info)),
    procformat(io_lib:format("~w",[Name]),
	       io_lib:format("~w",[Pid]),
	       io_lib:format("~s",[mfa_string(Call)]),
	       integer_to_list(Reds), integer_to_list(LM)).

procformat(Name, Pid, Call, Reds, LM) ->
    format("~-21s ~-12s ~-25s ~12s ~4s~n", [Name,Pid,Call,Reds,LM]).

portline(Name, Info, Id) ->
    Cmd = fetch(name, Info),
    portformat(io_lib:format("~w",[Name]), 
	       erlang:port_to_list(Id),
	       Cmd).

portformat(Name, Id, Cmd) ->
    format("~-21s ~-15s ~-40s~n", [Name,Id,Cmd]).

%% pwd()
%% cd(Directory)
%%  These are just wrappers around the file:get/set_cwd functions.

-spec pwd() -> 'ok'.

pwd() ->
    case file:get_cwd() of
	{ok, Str} ->
	    ok = io:format("~ts\n", [Str]);
	{error, _} ->
	    ok = io:format("Cannot determine current directory\n")
    end.

-spec cd(Dir) -> 'ok' when
      Dir :: file:name().

cd(Dir) ->
    _ = file:set_cwd(Dir),
    pwd().

%% ls()
%% ls(Directory)
%%  The strategy is to print in fixed width files.

-spec ls() -> 'ok'.

ls() ->
    ls(".").

-spec ls(Dir) -> 'ok' when
      Dir :: file:name().

ls(Dir) ->
    case file:list_dir(Dir) of
	{ok, Entries} ->
	    ls_print(sort(Entries));
	{error, enotdir} ->
	    ls_print([Dir]);
	{error, Error} ->
	    format("~ts\n", [file:format_error(Error)])
    end.

ls_print([]) -> ok;
ls_print(L) ->
    Width = min([max(lengths(L, [])), 40]) + 5,
    ls_print(L, Width, 0).

ls_print(X, Width, Len) when Width + Len >= 80 ->
    io:nl(),
    ls_print(X, Width, 0);
ls_print([H|T], Width, Len) ->
    io:format("~-*ts",[Width,H]),
    ls_print(T, Width, Len+Width);
ls_print([], _, _) ->
    io:nl().

lengths([H|T], L) -> lengths(T, [length(H)|L]);
lengths([], L)    -> L.

w(X) ->
    io_lib:write(X).

%%
%% memory/[0,1]
%%

-spec memory() -> [{Type, Size}] when
      Type :: atom(),
      Size :: non_neg_integer().

memory() -> erlang:memory().

-spec memory(Type) -> Size when
               Type :: atom(),
               Size :: non_neg_integer()
          ; (Types) -> [{Type, Size}] when
               Types :: [Type],
               Type :: atom(),
               Size :: non_neg_integer().

memory(TypeSpec) -> erlang:memory(TypeSpec).

%%
%% uptime/0
%%

-spec uptime() -> 'ok'.

uptime() ->
    io:format("~s~n", [uptime(get_uptime())]).

uptime({D, {H, M, S}}) ->
    lists:flatten(
      [[ io_lib:format("~p days, ", [D]) || D > 0 ],
       [ io_lib:format("~p hours, ", [H]) || D+H > 0 ],
       [ io_lib:format("~p minutes and ", [M]) || D+H+M > 0 ],
       io_lib:format("~p seconds", [S])]).

get_uptime() ->
    {UpTime, _} = erlang:statistics(wall_clock),
    calendar:seconds_to_daystime(UpTime div 1000).

%%
%% Cross Reference Check
%% 
%%-spec xm(module() | file:filename()) -> xref:m/1 return
xm(M) ->
    appcall(tools, xref, m, [M]).

%%
%% Call yecc 
%% 
%%-spec y(file:name()) -> yecc:file/2 return
y(File) -> y(File, []).

%%-spec y(file:name(), [yecc:option()]) -> yecc:file/2 return
y(File, Opts) ->
    appcall(parsetools, yecc, file, [File, Opts]).


%%
%% Avoid creating strong components in xref and dialyzer by making calls
%% from helper functions to other applications indirect.
%%

appcall(App, M, F, Args) ->
    try
	apply(M, F, Args)
    catch
	error:undef ->
	    case erlang:get_stacktrace() of
		[{M,F,Args,_}|_] ->
		    Arity = length(Args),
		    io:format("Call to ~w:~w/~w in application ~w failed.\n",
			      [M,F,Arity,App]);
		Stk ->
		    erlang:raise(error, undef, Stk)
	    end
    end.