summaryrefslogtreecommitdiff
path: root/ext/etc/etc.c
blob: 94b9cc34f001644f0dba7118f1520a4610c10e42 (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
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
/************************************************

  etc.c -

  $Author$
  created at: Tue Mar 22 18:39:19 JST 1994

************************************************/

#include "ruby.h"
#include "ruby/encoding.h"
#include "ruby/io.h"

#include <sys/types.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#ifdef HAVE_GETPWENT
#include <pwd.h>
#endif

#ifdef HAVE_GETGRENT
#include <grp.h>
#endif

#include <errno.h>

#ifdef HAVE_SYS_UTSNAME_H
#include <sys/utsname.h>
#endif

static VALUE sPasswd;
#ifdef HAVE_GETGRENT
static VALUE sGroup;
#endif

#ifdef _WIN32
#include <shlobj.h>
#ifndef CSIDL_COMMON_APPDATA
#define CSIDL_COMMON_APPDATA 35
#endif
#define HAVE_UNAME 1
#endif

#ifndef _WIN32
char *getenv();
#endif
char *getlogin();

#include "constdefs.h"

/* call-seq:
 *	getlogin	->  String
 *
 * Returns the short user name of the currently logged in user.
 * Unfortunately, it is often rather easy to fool ::getlogin.
 *
 * Avoid ::getlogin for security-related purposes.
 *
 * If ::getlogin fails, try ::getpwuid.
 *
 * See the unix manpage for <code>getpwuid(3)</code> for more detail.
 *
 * e.g.
 *   Etc.getlogin -> 'guest'
 */
static VALUE
etc_getlogin(VALUE obj)
{
    char *login;

#ifdef HAVE_GETLOGIN
    login = getlogin();
    if (!login) login = getenv("USER");
#else
    login = getenv("USER");
#endif

    if (login)
	return rb_tainted_str_new2(login);
    return Qnil;
}

#if defined(HAVE_GETPWENT) || defined(HAVE_GETGRENT)
static VALUE
safe_setup_str(const char *str)
{
    if (str == 0) str = "";
    return rb_tainted_str_new2(str);
}

static VALUE
safe_setup_locale_str(const char *str)
{
    if (str == 0) str = "";
    return rb_locale_str_new_cstr(str);
}

static VALUE
safe_setup_filesystem_str(const char *str)
{
    if (str == 0) str = "";
    return rb_filesystem_str_new_cstr(str);
}
#endif

#ifdef HAVE_GETPWENT
static VALUE
setup_passwd(struct passwd *pwd)
{
    if (pwd == 0) rb_sys_fail("/etc/passwd");
    return rb_struct_new(sPasswd,
			 safe_setup_locale_str(pwd->pw_name),
#ifdef HAVE_STRUCT_PASSWD_PW_PASSWD
			 safe_setup_str(pwd->pw_passwd),
#endif
			 UIDT2NUM(pwd->pw_uid),
			 GIDT2NUM(pwd->pw_gid),
#ifdef HAVE_STRUCT_PASSWD_PW_GECOS
			 safe_setup_locale_str(pwd->pw_gecos),
#endif
			 safe_setup_filesystem_str(pwd->pw_dir),
			 safe_setup_filesystem_str(pwd->pw_shell),
#ifdef HAVE_STRUCT_PASSWD_PW_CHANGE
			 INT2NUM(pwd->pw_change),
#endif
#ifdef HAVE_STRUCT_PASSWD_PW_QUOTA
			 INT2NUM(pwd->pw_quota),
#endif
#ifdef HAVE_STRUCT_PASSWD_PW_AGE
			 PW_AGE2VAL(pwd->pw_age),
#endif
#ifdef HAVE_STRUCT_PASSWD_PW_CLASS
			 safe_setup_locale_str(pwd->pw_class),
#endif
#ifdef HAVE_STRUCT_PASSWD_PW_COMMENT
			 safe_setup_locale_str(pwd->pw_comment),
#endif
#ifdef HAVE_STRUCT_PASSWD_PW_EXPIRE
			 INT2NUM(pwd->pw_expire),
#endif
			 0		/*dummy*/
	);
}
#endif

/* call-seq:
 *	getpwuid(uid)	->  Passwd
 *
 * Returns the /etc/passwd information for the user with the given integer +uid+.
 *
 * The information is returned as a Passwd struct.
 *
 * If +uid+ is omitted, the value from <code>Passwd[:uid]</code> is returned
 * instead.
 *
 * See the unix manpage for <code>getpwuid(3)</code> for more detail.
 *
 * === Example:
 *
 *	Etc.getpwuid(0)
 *	#=> #<struct Etc::Passwd name="root", passwd="x", uid=0, gid=0, gecos="root",dir="/root", shell="/bin/bash">
 */
static VALUE
etc_getpwuid(int argc, VALUE *argv, VALUE obj)
{
#if defined(HAVE_GETPWENT)
    VALUE id;
    rb_uid_t uid;
    struct passwd *pwd;

    if (rb_scan_args(argc, argv, "01", &id) == 1) {
	uid = NUM2UIDT(id);
    }
    else {
	uid = getuid();
    }
    pwd = getpwuid(uid);
    if (pwd == 0) rb_raise(rb_eArgError, "can't find user for %d", (int)uid);
    return setup_passwd(pwd);
#else
    return Qnil;
#endif
}

/* call-seq:
 *	getpwnam(name)	->  Passwd
 *
 * Returns the /etc/passwd information for the user with specified login
 * +name+.
 *
 * The information is returned as a Passwd struct.
 *
 * See the unix manpage for <code>getpwnam(3)</code> for more detail.
 *
 * === Example:
 *
 *	Etc.getpwnam('root')
 *	#=> #<struct Etc::Passwd name="root", passwd="x", uid=0, gid=0, gecos="root",dir="/root", shell="/bin/bash">
 */
static VALUE
etc_getpwnam(VALUE obj, VALUE nam)
{
#ifdef HAVE_GETPWENT
    struct passwd *pwd;

    SafeStringValue(nam);
    pwd = getpwnam(RSTRING_PTR(nam));
    if (pwd == 0) rb_raise(rb_eArgError, "can't find user for %"PRIsVALUE, nam);
    return setup_passwd(pwd);
#else
    return Qnil;
#endif
}

#ifdef HAVE_GETPWENT
static int passwd_blocking = 0;
static VALUE
passwd_ensure(void)
{
    endpwent();
    passwd_blocking = (int)Qfalse;
    return Qnil;
}

static VALUE
passwd_iterate(void)
{
    struct passwd *pw;

    setpwent();
    while (pw = getpwent()) {
	rb_yield(setup_passwd(pw));
    }
    return Qnil;
}

static void
each_passwd(void)
{
    if (passwd_blocking) {
	rb_raise(rb_eRuntimeError, "parallel passwd iteration");
    }
    passwd_blocking = (int)Qtrue;
    rb_ensure(passwd_iterate, 0, passwd_ensure, 0);
}
#endif

/* call-seq:
 *	Etc.passwd { |struct| block }	->  Passwd
 *	Etc.passwd			->  Passwd
 *
 * Provides a convenient Ruby iterator which executes a block for each entry
 * in the /etc/passwd file.
 *
 * The code block is passed an Passwd struct.
 *
 * See ::getpwent above for details.
 *
 * Example:
 *
 *     require 'etc'
 *
 *     Etc.passwd {|u|
 *       puts u.name + " = " + u.gecos
 *     }
 *
 */
static VALUE
etc_passwd(VALUE obj)
{
#ifdef HAVE_GETPWENT
    struct passwd *pw;

    if (rb_block_given_p()) {
	each_passwd();
    }
    else if (pw = getpwent()) {
	return setup_passwd(pw);
    }
#endif
    return Qnil;
}

/* call-seq:
 *	Etc::Passwd.each { |struct| block }	->  Passwd
 *	Etc::Passwd.each			->  Enumerator
 *
 * Iterates for each entry in the /etc/passwd file if a block is given.
 *
 * If no block is given, returns the Enumerator.
 *
 * The code block is passed an Passwd struct.
 *
 * See ::getpwent above for details.
 *
 * Example:
 *
 *     require 'etc'
 *
 *     Etc::Passwd.each {|u|
 *       puts u.name + " = " + u.gecos
 *     }
 *
 *     Etc::Passwd.collect {|u| u.gecos}
 *     Etc::Passwd.collect {|u| u.gecos}
 *
 */
static VALUE
etc_each_passwd(VALUE obj)
{
#ifdef HAVE_GETPWENT
    RETURN_ENUMERATOR(obj, 0, 0);
    each_passwd();
#endif
    return obj;
}

/* Resets the process of reading the /etc/passwd file, so that the next call
 * to ::getpwent will return the first entry again.
 */
static VALUE
etc_setpwent(VALUE obj)
{
#ifdef HAVE_GETPWENT
    setpwent();
#endif
    return Qnil;
}

/* Ends the process of scanning through the /etc/passwd file begun with
 * ::getpwent, and closes the file.
 */
static VALUE
etc_endpwent(VALUE obj)
{
#ifdef HAVE_GETPWENT
    endpwent();
#endif
    return Qnil;
}

/* Returns an entry from the /etc/passwd file.
 *
 * The first time it is called it opens the file and returns the first entry;
 * each successive call returns the next entry, or +nil+ if the end of the file
 * has been reached.
 *
 * To close the file when processing is complete, call ::endpwent.
 *
 * Each entry is returned as a Passwd struct.
 *
 */
static VALUE
etc_getpwent(VALUE obj)
{
#ifdef HAVE_GETPWENT
    struct passwd *pw;

    if (pw = getpwent()) {
	return setup_passwd(pw);
    }
#endif
    return Qnil;
}

#ifdef HAVE_GETGRENT
static VALUE
setup_group(struct group *grp)
{
    VALUE mem;
    char **tbl;

    mem = rb_ary_new();
    tbl = grp->gr_mem;
    while (*tbl) {
	rb_ary_push(mem, safe_setup_locale_str(*tbl));
	tbl++;
    }
    return rb_struct_new(sGroup,
			 safe_setup_locale_str(grp->gr_name),
#ifdef HAVE_STRUCT_GROUP_GR_PASSWD
			 safe_setup_str(grp->gr_passwd),
#endif
			 GIDT2NUM(grp->gr_gid),
			 mem);
}
#endif

/* call-seq:
 *	getgrgid(group_id)  ->	Group
 *
 * Returns information about the group with specified integer +group_id+,
 * as found in /etc/group.
 *
 * The information is returned as a Group struct.
 *
 * See the unix manpage for <code>getgrgid(3)</code> for more detail.
 *
 * === Example:
 *
 *	Etc.getgrgid(100)
 *	#=> #<struct Etc::Group name="users", passwd="x", gid=100, mem=["meta", "root"]>
 *
 */
static VALUE
etc_getgrgid(int argc, VALUE *argv, VALUE obj)
{
#ifdef HAVE_GETGRENT
    VALUE id;
    gid_t gid;
    struct group *grp;

    if (rb_scan_args(argc, argv, "01", &id) == 1) {
	gid = NUM2GIDT(id);
    }
    else {
	gid = getgid();
    }
    grp = getgrgid(gid);
    if (grp == 0) rb_raise(rb_eArgError, "can't find group for %d", (int)gid);
    return setup_group(grp);
#else
    return Qnil;
#endif
}

/* call-seq:
 *	getgrnam(name)	->  Group
 *
 * Returns information about the group with specified +name+, as found in
 * /etc/group.
 *
 * The information is returned as a Group struct.
 *
 * See the unix manpage for <code>getgrnam(3)</code> for more detail.
 *
 * === Example:
 *
 *	Etc.getgrnam('users')
 *	#=> #<struct Etc::Group name="users", passwd="x", gid=100, mem=["meta", "root"]>
 *
 */
static VALUE
etc_getgrnam(VALUE obj, VALUE nam)
{
#ifdef HAVE_GETGRENT
    struct group *grp;

    SafeStringValue(nam);
    grp = getgrnam(RSTRING_PTR(nam));
    if (grp == 0) rb_raise(rb_eArgError, "can't find group for %"PRIsVALUE, nam);
    return setup_group(grp);
#else
    return Qnil;
#endif
}

#ifdef HAVE_GETGRENT
static int group_blocking = 0;
static VALUE
group_ensure(void)
{
    endgrent();
    group_blocking = (int)Qfalse;
    return Qnil;
}


static VALUE
group_iterate(void)
{
    struct group *pw;

    setgrent();
    while (pw = getgrent()) {
	rb_yield(setup_group(pw));
    }
    return Qnil;
}

static void
each_group(void)
{
    if (group_blocking) {
	rb_raise(rb_eRuntimeError, "parallel group iteration");
    }
    group_blocking = (int)Qtrue;
    rb_ensure(group_iterate, 0, group_ensure, 0);
}
#endif

/* Provides a convenient Ruby iterator which executes a block for each entry
 * in the /etc/group file.
 *
 * The code block is passed an Group struct.
 *
 * See ::getgrent above for details.
 *
 * Example:
 *
 *     require 'etc'
 *
 *     Etc.group {|g|
 *       puts g.name + ": " + g.mem.join(', ')
 *     }
 *
 */
static VALUE
etc_group(VALUE obj)
{
#ifdef HAVE_GETGRENT
    struct group *grp;

    if (rb_block_given_p()) {
	each_group();
    }
    else if (grp = getgrent()) {
	return setup_group(grp);
    }
#endif
    return Qnil;
}

#ifdef HAVE_GETGRENT
/* call-seq:
 *	Etc::Group.each { |group| block }   ->	obj
 *	Etc::Group.each			    ->	Enumerator
 *
 * Iterates for each entry in the /etc/group file if a block is given.
 *
 * If no block is given, returns the Enumerator.
 *
 * The code block is passed a Group struct.
 *
 * Example:
 *
 *     require 'etc'
 *
 *     Etc::Group.each {|g|
 *       puts g.name + ": " + g.mem.join(', ')
 *     }
 *
 *     Etc::Group.collect {|g| g.name}
 *     Etc::Group.select {|g| !g.mem.empty?}
 *
 */
static VALUE
etc_each_group(VALUE obj)
{
    RETURN_ENUMERATOR(obj, 0, 0);
    each_group();
    return obj;
}
#endif

/* Resets the process of reading the /etc/group file, so that the next call
 * to ::getgrent will return the first entry again.
 */
static VALUE
etc_setgrent(VALUE obj)
{
#ifdef HAVE_GETGRENT
    setgrent();
#endif
    return Qnil;
}

/* Ends the process of scanning through the /etc/group file begun by
 * ::getgrent, and closes the file.
 */
static VALUE
etc_endgrent(VALUE obj)
{
#ifdef HAVE_GETGRENT
    endgrent();
#endif
    return Qnil;
}

/* Returns an entry from the /etc/group file.
 *
 * The first time it is called it opens the file and returns the first entry;
 * each successive call returns the next entry, or +nil+ if the end of the file
 * has been reached.
 *
 * To close the file when processing is complete, call ::endgrent.
 *
 * Each entry is returned as a Group struct
 */
static VALUE
etc_getgrent(VALUE obj)
{
#ifdef HAVE_GETGRENT
    struct group *gr;

    if (gr = getgrent()) {
	return setup_group(gr);
    }
#endif
    return Qnil;
}

#define numberof(array) (sizeof(array) / sizeof(*(array)))

#ifdef _WIN32
VALUE rb_w32_special_folder(int type);
UINT rb_w32_system_tmpdir(WCHAR *path, UINT len);
VALUE rb_w32_conv_from_wchar(const WCHAR *wstr, rb_encoding *enc);
#endif

/*
 * Returns system configuration directory.
 *
 * This is typically "/etc", but is modified by the prefix used when Ruby was
 * compiled. For example, if Ruby is built and installed in /usr/local, returns
 * "/usr/local/etc".
 */
static VALUE
etc_sysconfdir(VALUE obj)
{
#ifdef _WIN32
    return rb_w32_special_folder(CSIDL_COMMON_APPDATA);
#else
    return rb_filesystem_str_new_cstr(SYSCONFDIR);
#endif
}

/*
 * Returns system temporary directory; typically "/tmp".
 */
static VALUE
etc_systmpdir(void)
{
    VALUE tmpdir;
#ifdef _WIN32
    WCHAR path[_MAX_PATH];
    UINT len = rb_w32_system_tmpdir(path, numberof(path));
    if (!len) return Qnil;
    tmpdir = rb_w32_conv_from_wchar(path, rb_filesystem_encoding());
#else
    const char default_tmp[] = "/tmp";
    const char *tmpstr = default_tmp;
    size_t tmplen = strlen(default_tmp);
# if defined _CS_DARWIN_USER_TEMP_DIR
    #ifndef MAXPATHLEN
    #define MAXPATHLEN 1024
    #endif
    char path[MAXPATHLEN];
    size_t len;
    len = confstr(_CS_DARWIN_USER_TEMP_DIR, path, sizeof(path));
    if (len > 0) {
	tmpstr = path;
	tmplen = len - 1;
    }
# endif
    tmpdir = rb_filesystem_str_new(tmpstr, tmplen);
#endif
    FL_UNSET(tmpdir, FL_TAINT);
    return tmpdir;
}

#ifdef HAVE_UNAME
/*
 * Returns the system information obtained by uname system call.
 *
 * The return value is a hash which has 5 keys at least:
 *   :sysname, :nodename, :release, :version, :machine
 *
 * Example:
 *
 *   require 'etc'
 *   require 'pp'
 *
 *   pp Etc.uname
 *   #=> {:sysname=>"Linux",
 *   #    :nodename=>"boron",
 *   #    :release=>"2.6.18-6-xen-686",
 *   #    :version=>"#1 SMP Thu Nov 5 19:54:42 UTC 2009",
 *   #    :machine=>"i686"}
 *
 */
static VALUE
etc_uname(VALUE obj)
{
#ifdef _WIN32
    OSVERSIONINFOW v;
    SYSTEM_INFO s;
    const char *sysname, *mach;
    VALUE result, release, version;
    VALUE vbuf, nodename = Qnil;
    DWORD len = 0;
    WCHAR *buf;

    v.dwOSVersionInfoSize = sizeof(v);
    if (!GetVersionExW(&v))
        rb_sys_fail("GetVersionEx");

    result = rb_hash_new();
    switch (v.dwPlatformId) {
      case VER_PLATFORM_WIN32s:
	sysname = "Win32s";
	break;
      case VER_PLATFORM_WIN32_NT:
	sysname = "Windows_NT";
	break;
      case VER_PLATFORM_WIN32_WINDOWS:
      default:
	sysname = "Windows";
	break;
    }
    rb_hash_aset(result, ID2SYM(rb_intern("sysname")), rb_str_new_cstr(sysname));
    release = rb_sprintf("%lu.%lu.%lu", v.dwMajorVersion, v.dwMinorVersion, v.dwBuildNumber);
    rb_hash_aset(result, ID2SYM(rb_intern("release")), release);
    version = rb_sprintf("%s Version %"PRIsVALUE": %"PRIsVALUE, sysname, release,
			 rb_w32_conv_from_wchar(v.szCSDVersion, rb_utf8_encoding()));
    rb_hash_aset(result, ID2SYM(rb_intern("version")), version);

# if defined _MSC_VER && _MSC_VER < 1300
#   define GET_COMPUTER_NAME(ptr, plen) GetComputerNameW(ptr, plen)
# else
#   define GET_COMPUTER_NAME(ptr, plen) GetComputerNameExW(ComputerNameDnsFullyQualified, ptr, plen)
# endif
    GET_COMPUTER_NAME(NULL, &len);
    buf = ALLOCV_N(WCHAR, vbuf, len);
    if (GET_COMPUTER_NAME(buf, &len)) {
	nodename = rb_w32_conv_from_wchar(buf, rb_utf8_encoding());
    }
    ALLOCV_END(vbuf);
    if (NIL_P(nodename)) nodename = rb_str_new(0, 0);
    rb_hash_aset(result, ID2SYM(rb_intern("nodename")), nodename);

# ifndef PROCESSOR_ARCHITECTURE_AMD64
#   define PROCESSOR_ARCHITECTURE_AMD64 9
# endif
# ifndef PROCESSOR_ARCHITECTURE_IA64
#   define PROCESSOR_ARCHITECTURE_IA64 6
# endif
# ifndef PROCESSOR_ARCHITECTURE_INTEL
#   define PROCESSOR_ARCHITECTURE_INTEL 0
# endif
    GetSystemInfo(&s);
    switch (s.wProcessorArchitecture) {
      case PROCESSOR_ARCHITECTURE_AMD64:
	mach = "x64";
	break;
      case PROCESSOR_ARCHITECTURE_ARM:
	mach = "ARM";
	break;
      case PROCESSOR_ARCHITECTURE_IA64:
	mach = "IA64";
	break;
      case PROCESSOR_ARCHITECTURE_INTEL:
	mach = "x86";
	break;
      default:
	mach = "unknown";
	break;
    }

    rb_hash_aset(result, ID2SYM(rb_intern("machine")), rb_str_new_cstr(mach));
#else
    struct utsname u;
    int ret;
    VALUE result;

    ret = uname(&u);
    if (ret == -1)
        rb_sys_fail("uname");

    result = rb_hash_new();
    rb_hash_aset(result, ID2SYM(rb_intern("sysname")), rb_str_new_cstr(u.sysname));
    rb_hash_aset(result, ID2SYM(rb_intern("nodename")), rb_str_new_cstr(u.nodename));
    rb_hash_aset(result, ID2SYM(rb_intern("release")), rb_str_new_cstr(u.release));
    rb_hash_aset(result, ID2SYM(rb_intern("version")), rb_str_new_cstr(u.version));
    rb_hash_aset(result, ID2SYM(rb_intern("machine")), rb_str_new_cstr(u.machine));
#endif

    return result;
}
#else
#define etc_uname rb_f_notimplement
#endif

#ifdef HAVE_SYSCONF
/*
 * Returns system configuration variable using sysconf().
 *
 * _name_ should be a constant under <code>Etc</code> which begins with <code>SC_</code>.
 *
 * The return value is an integer or nil.
 * nil means indefinite limit.  (sysconf() returns -1 but errno is not set.)
 *
 *   Etc.sysconf(Etc::SC_ARG_MAX) #=> 2097152
 *   Etc.sysconf(Etc::SC_LOGIN_NAME_MAX) #=> 256
 *
 */
static VALUE
etc_sysconf(VALUE obj, VALUE arg)
{
    int name;
    long ret;

    name = NUM2INT(arg);

    errno = 0;
    ret = sysconf(name);
    if (ret == -1) {
        if (errno == 0) /* no limit */
            return Qnil;
        rb_sys_fail("sysconf");
    }
    return LONG2NUM(ret);
}
#else
#define etc_sysconf rb_f_notimplement
#endif

#ifdef HAVE_CONFSTR
/*
 * Returns system configuration variable using confstr().
 *
 * _name_ should be a constant under <code>Etc</code> which begins with <code>CS_</code>.
 *
 * The return value is a string or nil.
 * nil means no configuration-defined value.  (confstr() returns 0 but errno is not set.)
 *
 *   Etc.confstr(Etc::CS_PATH) #=> "/bin:/usr/bin"
 *
 *   # GNU/Linux
 *   Etc.confstr(Etc::CS_GNU_LIBC_VERSION) #=> "glibc 2.18"
 *   Etc.confstr(Etc::CS_GNU_LIBPTHREAD_VERSION) #=> "NPTL 2.18"
 *
 */
static VALUE
etc_confstr(VALUE obj, VALUE arg)
{
    int name;
    char localbuf[128], *buf = localbuf;
    size_t bufsize = sizeof(localbuf), ret;
    VALUE tmp;

    name = NUM2INT(arg);

    errno = 0;
    ret = confstr(name, buf, bufsize);
    if (bufsize < ret) {
        bufsize = ret;
        buf = ALLOCV_N(char, tmp, bufsize);
        errno = 0;
        ret = confstr(name, buf, bufsize);
    }
    if (bufsize < ret)
        rb_bug("required buffer size for confstr() changed dynamically.");
    if (ret == 0) {
        if (errno == 0) /* no configuration-defined value */
            return Qnil;
        rb_sys_fail("confstr");
    }
    return rb_str_new_cstr(buf);
}
#else
#define etc_confstr rb_f_notimplement
#endif

#ifdef HAVE_FPATHCONF
/*
 * Returns pathname configuration variable using fpathconf().
 *
 * _name_ should be a constant under <code>Etc</code> which begins with <code>PC_</code>.
 *
 * The return value is an integer or nil.
 * nil means indefinite limit.  (fpathconf() returns -1 but errno is not set.)
 *
 *   require 'etc'
 *   IO.pipe {|r, w|
 *     p w.pathconf(Etc::PC_PIPE_BUF) #=> 4096
 *   }
 *
 */
static VALUE
io_pathconf(VALUE io, VALUE arg)
{
    int name;
    long ret;
    rb_io_t *fptr;

    name = NUM2INT(arg);

    GetOpenFile(io, fptr);

    errno = 0;
    ret = fpathconf(fptr->fd, name);
    if (ret == -1) {
        if (errno == 0) /* no limit */
            return Qnil;
        rb_sys_fail("fpathconf");
    }
    return LONG2NUM(ret);
}
#else
#define io_pathconf rb_f_notimplement
#endif

#if (defined(HAVE_SYSCONF) && defined(_SC_NPROCESSORS_ONLN)) || defined(_WIN32)
/*
 * Returns the number of online processors.
 *
 * The result is intended as the number of processes to
 * use all available processors.
 *
 * This method is implemented as:
 * - sysconf(_SC_NPROCESSORS_ONLN): GNU/Linux, NetBSD, FreeBSD, OpenBSD, DragonFly BSD, OpenIndiana, Mac OS X, AIX
 *
 * Example:
 *
 *   require 'etc'
 *   p Etc.nprocessors #=> 4
 *
 */
static VALUE
etc_nprocessors(VALUE obj)
{
    long ret;

#if !defined(_WIN32)
    errno = 0;
    ret = sysconf(_SC_NPROCESSORS_ONLN);
    if (ret == -1) {
        rb_sys_fail("sysconf(_SC_NPROCESSORS_ONLN)");
    }
#else
    SYSTEM_INFO si;
    GetSystemInfo(&si);
    ret = (long)si.dwNumberOfProcessors;
#endif
    return LONG2NUM(ret);
}
#else
#define etc_nprocessors rb_f_notimplement
#endif

/*
 * The Etc module provides access to information typically stored in
 * files in the /etc directory on Unix systems.
 *
 * The information accessible consists of the information found in the
 * /etc/passwd and /etc/group files, plus information about the system's
 * temporary directory (/tmp) and configuration directory (/etc).
 *
 * The Etc module provides a more reliable way to access information about
 * the logged in user than environment variables such as +$USER+.
 *
 * == Example:
 *
 *     require 'etc'
 *
 *     login = Etc.getlogin
 *     info = Etc.getpwnam(login)
 *     username = info.gecos.split(/,/).first
 *     puts "Hello #{username}, I see your login name is #{login}"
 *
 * Note that the methods provided by this module are not always secure.
 * It should be used for informational purposes, and not for security.
 *
 * All operations defined in this module are class methods, so that you can
 * include the Etc module into your class.
 */
void
Init_etc(void)
{
    VALUE mEtc;

    mEtc = rb_define_module("Etc");
    init_constants(mEtc);

    rb_define_module_function(mEtc, "getlogin", etc_getlogin, 0);

    rb_define_module_function(mEtc, "getpwuid", etc_getpwuid, -1);
    rb_define_module_function(mEtc, "getpwnam", etc_getpwnam, 1);
    rb_define_module_function(mEtc, "setpwent", etc_setpwent, 0);
    rb_define_module_function(mEtc, "endpwent", etc_endpwent, 0);
    rb_define_module_function(mEtc, "getpwent", etc_getpwent, 0);
    rb_define_module_function(mEtc, "passwd", etc_passwd, 0);

    rb_define_module_function(mEtc, "getgrgid", etc_getgrgid, -1);
    rb_define_module_function(mEtc, "getgrnam", etc_getgrnam, 1);
    rb_define_module_function(mEtc, "group", etc_group, 0);
    rb_define_module_function(mEtc, "setgrent", etc_setgrent, 0);
    rb_define_module_function(mEtc, "endgrent", etc_endgrent, 0);
    rb_define_module_function(mEtc, "getgrent", etc_getgrent, 0);
    rb_define_module_function(mEtc, "sysconfdir", etc_sysconfdir, 0);
    rb_define_module_function(mEtc, "systmpdir", etc_systmpdir, 0);
    rb_define_module_function(mEtc, "uname", etc_uname, 0);
    rb_define_module_function(mEtc, "sysconf", etc_sysconf, 1);
    rb_define_module_function(mEtc, "confstr", etc_confstr, 1);
    rb_define_method(rb_cIO, "pathconf", io_pathconf, 1);
    rb_define_module_function(mEtc, "nprocessors", etc_nprocessors, 0);

    sPasswd =  rb_struct_define_under(mEtc, "Passwd",
				      "name",
#ifdef HAVE_STRUCT_PASSWD_PW_PASSWD
				      "passwd",
#endif
				      "uid",
				      "gid",
#ifdef HAVE_STRUCT_PASSWD_PW_GECOS
				      "gecos",
#endif
				      "dir",
				      "shell",
#ifdef HAVE_STRUCT_PASSWD_PW_CHANGE
				      "change",
#endif
#ifdef HAVE_STRUCT_PASSWD_PW_QUOTA
				      "quota",
#endif
#ifdef HAVE_STRUCT_PASSWD_PW_AGE
				      "age",
#endif
#ifdef HAVE_STRUCT_PASSWD_PW_CLASS
				      "uclass",
#endif
#ifdef HAVE_STRUCT_PASSWD_PW_COMMENT
				      "comment",
#endif
#ifdef HAVE_STRUCT_PASSWD_PW_EXPIRE
				      "expire",
#endif
				      NULL);
#if 0
    /* Define-const: Passwd
     *
     * Passwd is a Struct that contains the following members:
     *
     * name::
     *	    contains the short login name of the user as a String.
     * passwd::
     *	    contains the encrypted password of the user as a String.
     *	    an 'x' is returned if shadow passwords are in use. An '*' is returned
     *      if the user cannot log in using a password.
     * uid::
     *	    contains the integer user ID (uid) of the user.
     * gid::
     *	    contains the integer group ID (gid) of the user's primary group.
     * dir::
     *	    contains the path to the home directory of the user as a String.
     * shell::
     *	    contains the path to the login shell of the user as a String.
     *
     * === The following members below are optional, and must be compiled with special flags:
     *
     * gecos::
     *     contains a longer String description of the user, such as
     *	   a full name. Some Unix systems provide structured information in the
     *     gecos field, but this is system-dependent.
     *     must be compiled with +HAVE_STRUCT_PASSWD_PW_GECOS+
     * change::
     *     password change time(integer) must be compiled with +HAVE_STRUCT_PASSWD_PW_CHANGE+
     * quota::
     *     quota value(integer) must be compiled with +HAVE_STRUCT_PASSWD_PW_QUOTA+
     * age::
     *     password age(integer) must be compiled with +HAVE_STRUCT_PASSWD_PW_AGE+
     * class::
     *     user access class(string) must be compiled with +HAVE_STRUCT_PASSWD_PW_CLASS+
     * comment::
     *     comment(string) must be compiled with +HAVE_STRUCT_PASSWD_PW_COMMENT+
     * expire::
     *	    account expiration time(integer) must be compiled with +HAVE_STRUCT_PASSWD_PW_EXPIRE+
     */
    rb_define_const(mEtc, "Passwd", sPasswd);
#endif
    rb_define_const(rb_cStruct, "Passwd", sPasswd); /* deprecated name */
    rb_extend_object(sPasswd, rb_mEnumerable);
    rb_define_singleton_method(sPasswd, "each", etc_each_passwd, 0);

#ifdef HAVE_GETGRENT
    sGroup = rb_struct_define_under(mEtc, "Group", "name",
#ifdef HAVE_STRUCT_GROUP_GR_PASSWD
				    "passwd",
#endif
				    "gid", "mem", NULL);

#if 0
    /* Define-const: Group
     *
     * Group is a Struct that is only available when compiled with +HAVE_GETGRENT+.
     *
     * The struct contains the following members:
     *
     * name::
     *	    contains the name of the group as a String.
     * passwd::
     *	    contains the encrypted password as a String. An 'x' is
     *	    returned if password access to the group is not available; an empty
     *	    string is returned if no password is needed to obtain membership of
     *	    the group.
     *
     *	    Must be compiled with +HAVE_STRUCT_GROUP_GR_PASSWD+.
     * gid::
     *	    contains the group's numeric ID as an integer.
     * mem::
     *	    is an Array of Strings containing the short login names of the
     *	    members of the group.
     */
    rb_define_const(mEtc, "Group", sGroup);
#endif
    rb_define_const(rb_cStruct, "Group", sGroup); /* deprecated name */
    rb_extend_object(sGroup, rb_mEnumerable);
    rb_define_singleton_method(sGroup, "each", etc_each_group, 0);
#endif
}