summaryrefslogtreecommitdiff
path: root/Build/source/texk/web2c/luatexdir/lua/loslibext.c
blob: fbe3f875148ded953f370b294952f6276ee4ec6e (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
/* loslibext.c
   
   Copyright 2006-2008 Taco Hoekwater <taco@luatex.org>

   This file is part of LuaTeX.

   LuaTeX is free software; you can redistribute it and/or modify it under
   the terms of the GNU General Public License as published by the Free
   Software Foundation; either version 2 of the License, or (at your
   option) any later version.

   LuaTeX is distributed in the hope that it will be useful, but WITHOUT
   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
   License for more details.

   You should have received a copy of the GNU General Public License along
   with LuaTeX; if not, see <http://www.gnu.org/licenses/>. */

#include "luatex-api.h"
#include <ptexlib.h>

#include <sys/stat.h>
#include <sys/types.h>
#include <time.h>

static const char _svn_version[] =
    "$Id: loslibext.c 2363 2009-04-30 07:47:37Z taco $ $URL: http://scm.foundry.supelec.fr/svn/luatex/trunk/source/texk/web2c/luatexdir/lua/loslibext.c $";

#if defined(_WIN32) || defined(WIN32) || defined(__NT__)
#  define MKDIR(a,b) mkdir(a)
#else
#  define MKDIR(a,b) mkdir(a,b)
#endif

/* An attempt to figure out the basic platform, does not
  care about niceties like version numbers yet,
  and ignores platforms where luatex is unlikely to 
  successfully compile without major prorting effort 
  (amiga|mac|os2|vms) */

#if defined(_WIN32) || defined(WIN32) || defined(__NT__)
#  define OS_PLATTYPE "windows"
#  define OS_PLATNAME "windows"
#elif defined(__GO32__) || defined(__DJGPP__) || defined(__DOS__)
#  define OS_PLATTYPE "msdos"
#  define OS_PLATNAME "msdos"
#else                           /* assume everything else is unix-y */
#  include <sys/utsname.h>
#  define OS_PLATTYPE "unix"
/* this is just a first guess */
#  if defined(__BSD__)
#    define OS_PLATNAME "bsd"
#  elif defined(__SYSV__)
#    define OS_PLATNAME "sysv"
#  else
#    define OS_PLATNAME "generic"
#  endif
/* attempt to be more precise */
#  if defined(__LINUX__) || defined (__linux)
#    undef OS_PLATNAME
#    define OS_PLATNAME "linux"
#  elif defined(__FREEBSD__) || defined(__FreeBSD__) || defined(__FreeBSD)
#    undef OS_PLATNAME
#    define OS_PLATNAME "freebsd"
#  elif defined(__OPENBSD__)  || defined(__OpenBSD)
#    undef OS_PLATNAME
#    define OS_PLATNAME "openbsd"
#  elif defined(__SOLARIS__)
#    undef OS_PLATNAME
#    define OS_PLATNAME "solaris"
#  elif defined(__SUNOS__) ||  defined(__SUN__) ||  defined(sun)
#    undef OS_PLATNAME
#    define OS_PLATNAME "sunos"
#  elif defined(HPUX) || defined(__hpux)
#    undef OS_PLATNAME
#    define OS_PLATNAME "hpux"
#  elif defined(__sgi)
#    undef OS_PLATNAME
#    define OS_PLATNAME "irix"
#  elif defined(__MACH__) && defined(__APPLE__)
#    undef OS_PLATNAME
#    define OS_PLATNAME "macosx"
#  endif
#endif





/* there could be more platforms that don't have these two,
 *  but win32 and sunos are for sure.
 * gettimeofday() for win32 is using an alternative definition
 */

#if (! defined(WIN32)) && (! defined(__SUNOS__))
#  include <sys/time.h>         /* gettimeofday() */
#  include <sys/times.h>        /* times() */
#  include <sys/wait.h>
#endif

/* set this to one for spawn instead of exec on windows */

#define DONT_REALLY_EXIT 1

#ifdef WIN32
#  include <process.h>
#  define spawn_command(a,b,c) _spawnvpe(_P_WAIT,(const char *)a,(const char* const*)b,(const char* const*)c)
#  if DONT_REALLY_EXIT
#    define exec_command(a,b,c) exit(spawn_command((a),(b),(c)))
#  else
#    define exec_command(a,b,c) _execvpe((const char *)a,(const char* const*)b,(const char* const*)c)
#  endif
#else
#  include <unistd.h>
#  define DEFAULT_PATH    "/bin:/usr/bin:."

static int exec_command(const char *file, char *const *argv, char *const *envp)
{
    char path[PATH_MAX];
    const char *searchpath, *esp;
    size_t prefixlen, filelen, totallen;

    if (strchr(file, '/'))      /* Specific path */
        return execve(file, argv, envp);

    filelen = strlen(file);

    searchpath = getenv("PATH");
    if (!searchpath)
        searchpath = DEFAULT_PATH;

    errno = ENOENT;             /* Default errno, if execve() doesn't  change it */

    do {
        esp = strchr(searchpath, ':');
        if (esp)
            prefixlen = esp - searchpath;
        else
            prefixlen = strlen(searchpath);

        if (prefixlen == 0 || searchpath[prefixlen - 1] == '/') {
            totallen = prefixlen + filelen;
            if (totallen >= PATH_MAX)
                continue;
            memcpy(path, searchpath, prefixlen);
            memcpy(path + prefixlen, file, filelen);
        } else {
            totallen = prefixlen + filelen + 1;
            if (totallen >= PATH_MAX)
                continue;
            memcpy(path, searchpath, prefixlen);
            path[prefixlen] = '/';
            memcpy(path + prefixlen + 1, file, filelen);
        }
        path[totallen] = '\0';

        execve(path, argv, envp);
        if (errno == E2BIG || errno == ENOEXEC ||
            errno == ENOMEM || errno == ETXTBSY)
            break;              /* Report this as an error, no more search */

        searchpath = esp + 1;
    } while (esp);

    return -1;
}

/* 
   It is not possible to mimic |spawnve()| completely. The main problem is
   that the |fork|--|waitpid| combination cannot really do identical error 
   reporting to the parent process, because it has to pass all the possible
   error conditions as well as the actual process return status through a 
   single 8-bit value.

   The current implementation tries to give back meaningful results for |execve()|
   errors in the child, for the cases that could also be returned by |spawnve()|,
   and for |ETXTBSY|, because that can be triggered by our path searching routine.

   This implementation does not differentiate abnormal status conditions reported 
   by |waitpid()|, but will simply return a single error indication value.

   For all this, hyjacking a bunch of numbers in the range 1...255 is needed. 
   The chance of collisions is hopefully diminished by using a rather random
   range in the 8-bit section.
*/

#  define INVALID_RET_E2BIG   143
#  define INVALID_RET_ENOENT  144
#  define INVALID_RET_ENOEXEC 145
#  define INVALID_RET_ENOMEM  146
#  define INVALID_RET_ETXTBSY 147
#  define INVALID_RET_UNKNOWN 148
#  define INVALID_RET_INTR    149

static int spawn_command(const char *file, char *const *argv, char *const *envp)
{
    pid_t pid, wait_pid;
    int status;
    pid = fork();
    if (pid < 0) {
        return -1;              /* fork failed */
    }
    if (pid > 0) {              /* parent */
        status = 0;
        wait_pid = waitpid(pid, &status, 0);
        if (wait_pid == pid) {
            if (WIFEXITED(status))
                return WEXITSTATUS(status);
            else
                return INVALID_RET_INTR;
        } else {
            return -1;          /* some waitpid error */
        }
    } else {
        int f;
        /* somewhat random upper limit. ignore errors on purpose */
        for (f = 0; f < 256; f++)
            (void) fsync(f);

        if (exec_command(file, argv, envp)) {
            /* let's hope no-one uses these values  */
            switch (errno) {
            case E2BIG:
                exit(INVALID_RET_E2BIG);
            case ETXTBSY:
                exit(INVALID_RET_ETXTBSY);
            case ENOENT:
                exit(INVALID_RET_ENOENT);
            case ENOEXEC:
                exit(INVALID_RET_ENOEXEC);
            case ENOMEM:
                exit(INVALID_RET_ENOMEM);
            default:
                exit(INVALID_RET_UNKNOWN);
            }
            return -1;
        }
    }
    return 0;
}

#endif

extern char **environ;

static char **do_split_command(char *maincmd)
{
    char *piece, *start_piece;
    char *cmd;
    char **cmdline = NULL;
    unsigned int i, j;
    int ret = 0;
    int in_string = 0;
    int quoted = 0;
    if (strlen(maincmd) == 0)
        return NULL;
    /* allocate the array of options first. it will probably be 
       be a little bit too big, but better too much than to little */
    j = 2;
    for (i = 0; i < strlen(maincmd); i++) {
        if (maincmd[i] == ' ')
            j++;
    }
    cmdline = malloc(sizeof(char *) * j);
    for (i = 0; i < j; i++) {
        cmdline[i] = NULL;
    }
    cmd = maincmd;
    i = 0;
    while (cmd[i] == ' ')
        i++;                    /* skip leading spaces */
    start_piece = malloc(strlen(cmd) + 1);      /* a buffer */
    piece = start_piece;
    for (; i <= strlen(maincmd); i++) {
        if (cmd[i] == '\\' &&
            (cmd[i + 1] == '\\' || cmd[i + 1] == '\'' || cmd[i + 1] == '"')) {
            quoted = 1;
            continue;
        }
        if (in_string && cmd[i] == in_string && !quoted) {
            in_string = 0;
            continue;
        }
        if ((cmd[i] == '"' || cmd[i] == '\'') && !quoted) {
            in_string = cmd[i];
            continue;
        }
        if ((in_string == 0 && cmd[i] == ' ') || cmd[i] == 0) {
            *piece = 0;
            cmdline[ret++] = xstrdup(start_piece);
            piece = start_piece;
            while (i < strlen(maincmd) && cmd[(i + 1)] == ' ')
                i++;
            continue;
        }
        *piece++ = cmd[i];
        quoted = 0;
    }
    xfree(start_piece);
    return cmdline;
}

static char **do_flatten_command(lua_State * L, char **runcmd)
{
    unsigned int i, j;
    char *s;
    char **cmdline = NULL;
    *runcmd = NULL;

    for (j = 1;; j++) {
        lua_rawgeti(L, -1, j);
        if (lua_isnil(L, -1)) {
            lua_pop(L, 1);
            break;
        }
        lua_pop(L, 1);
    }
    if (j == 1)
        return NULL;
    cmdline = malloc(sizeof(char *) * (j + 1));
    for (i = 1; i <= j; i++) {
        cmdline[i] = NULL;
        lua_rawgeti(L, -1, i);
        if (lua_isnil(L, -1) || (s = (char *) lua_tostring(L, -1)) == NULL) {
            lua_pop(L, 1);
            if (i == 1) {
                xfree(cmdline);
                return NULL;
            } else {
                break;
            }
        } else {
            lua_pop(L, 1);
            cmdline[(i - 1)] = xstrdup(s);
        }
    }
    cmdline[i] = NULL;

    lua_rawgeti(L, -1, 0);
    if (lua_isnil(L, -1) || (s = (char *) lua_tostring(L, -1)) == NULL) {
        *runcmd = cmdline[0];
    } else {
        *runcmd = xstrdup(s);
    }
    lua_pop(L, 1);

    return cmdline;
}


static int os_exec(lua_State * L)
{
    int allow = 0;
    char *maincmd = NULL, *runcmd = NULL;
    char *safecmd = NULL, *cmdname = NULL;
    char **cmdline = NULL;

    if (lua_gettop(L) != 1) {
        lua_pushnil(L);
        lua_pushliteral(L, "invalid arguments passed");
        return 2;
    }
    if (shellenabledp <= 0) {
        lua_pushnil(L);
        lua_pushliteral(L, "All command execution disabled.");
        return 2;
    }
    if (lua_type(L, 1) == LUA_TSTRING) {
        maincmd = (char *) lua_tostring(L, 1);
        cmdline = do_split_command(maincmd);
        runcmd = cmdline[0];
    } else if (lua_type(L, 1) == LUA_TTABLE) {
        cmdline = do_flatten_command(L, &runcmd);
    }
    /* If restrictedshell == 0, any command is allowed. */
    /* this is a little different from \write18/ os.execute processing
     * because it does not test for commands with fixed arguments,
     * but I am not so eager to attempt to fix that. Just document
     * that os.exec() checks only the command name.
     */
    if (restrictedshell == 0)
        allow = 1;
    else
        allow = shell_cmd_is_allowed(&runcmd, &safecmd, &cmdname);

    if (allow > 0 && cmdline != NULL && runcmd != NULL) {
#if defined(WIN32) && DONT_REALLY_EXIT
        if (allow == 2)
            exec_command(safecmd, cmdline, environ);
        else
            exec_command(runcmd, cmdline, environ);
#else
        {
            int r;
            if (allow == 2)
                r = exec_command(safecmd, cmdline, environ);
            else
                r = exec_command(runcmd, cmdline, environ);
            if (r == -1) {
                lua_pushnil(L);
                lua_pushfstring(L, "%s: %s", runcmd, strerror(errno));
                lua_pushnumber(L, errno);
                return 3;
            }
        }
#endif
    }
    if (safecmd)
        free(safecmd);
    if (cmdname)
        free(cmdname);
    if (allow == 0) {
        lua_pushnil(L);
        lua_pushliteral(L, "Command execution disabled via shell_escape='p'");
        return 2;
    }
    lua_pushnil(L);
    lua_pushliteral(L, "invalid command line passed");
    return 2;
}

#define do_error_return(A,B) do {                                       \
        lua_pushnil(L);                                                 \
        lua_pushfstring(L,"%s: %s",runcmd,(A));                         \
        lua_pushnumber(L, B);                                           \
        return 3;                                                       \
    } while (0)

static int os_spawn(lua_State * L)
{
    int allow = 0;
    char *maincmd = NULL, *runcmd = NULL;
    char *safecmd = NULL, *cmdname = NULL;
    char **cmdline = NULL;
    int i;

    if (lua_gettop(L) != 1) {
        lua_pushnil(L);
        lua_pushliteral(L, "invalid arguments passed");
        return 2;
    }
    if (shellenabledp <= 0) {
        lua_pushnil(L);
        lua_pushliteral(L, "All command execution disabled.");
        return 2;
    }
    if (lua_type(L, 1) == LUA_TSTRING) {
        maincmd = (char *) lua_tostring(L, 1);
        cmdline = do_split_command(maincmd);
        runcmd = cmdline[0];
    } else if (lua_type(L, 1) == LUA_TTABLE) {
        cmdline = do_flatten_command(L, &runcmd);
    }
    /* If restrictedshell == 0, any command is allowed. */
    /* this is a little different from \write18/ os.execute processing
     * because it does not test for commands with fixed arguments,
     * but I am not so eager to attempt to fix that. Just document
     * that os.exec() checks only the command name.
     */
    if (restrictedshell == 0)
        allow = 1;
    else
        allow = shell_cmd_is_allowed(&runcmd, &safecmd, &cmdname);
    if (allow > 0 && cmdline != NULL && runcmd != NULL) {
        if (allow == 2)
            i = spawn_command(safecmd, cmdline, environ);
        else
            i = spawn_command(runcmd, cmdline, environ);
        if (safecmd)
            free(safecmd);
        if (cmdname)
            free(cmdname);
        if (i == 0) {
            lua_pushnumber(L, i);
            return 1;
        } else if (i == -1) {
            /* this branch covers WIN32 as well as fork() and waitpid() errors */
            do_error_return(strerror(errno), errno);
#ifndef WIN32
        } else if (i == INVALID_RET_E2BIG) {
            do_error_return(strerror(E2BIG), i);
        } else if (i == INVALID_RET_ENOENT) {
            do_error_return(strerror(ENOENT), i);
        } else if (i == INVALID_RET_ENOEXEC) {
            do_error_return(strerror(ENOEXEC), i);
        } else if (i == INVALID_RET_ENOMEM) {
            do_error_return(strerror(ENOMEM), i);
        } else if (i == INVALID_RET_ETXTBSY) {
            do_error_return(strerror(ETXTBSY), i);
        } else if (i == INVALID_RET_UNKNOWN) {
            do_error_return("execution failed", i);
        } else if (i == INVALID_RET_INTR) {
            do_error_return("execution interrupted", i);
#endif
        } else {
            lua_pushnumber(L, i);
            return 1;
        }
    }
    if (safecmd)
        free(safecmd);
    if (cmdname)
        free(cmdname);
    if (allow == 0) {
        lua_pushnil(L);
        lua_pushliteral(L, "Command execution disabled via shell_escape='p'");
        return 2;
    }
    lua_pushnil(L);
    lua_pushliteral(L, "invalid command line passed");
    return 2;
}

/*  Hans wants to set env values */

static int os_setenv(lua_State * L)
{
    char *value, *key, *val;
    key = (char *) luaL_optstring(L, 1, NULL);
    val = (char *) luaL_optstring(L, 2, NULL);
    if (key) {
        if (val) {
            value = xmalloc(strlen(key) + strlen(val) + 2);
            sprintf(value, "%s=%s", key, val);
            if (putenv(value)) {
                return luaL_error(L, "unable to change environment");
            }
        } else {
#if defined(WIN32) || defined(__sun__) || defined(__sun) || defined(_AIX)
            value = xmalloc(strlen(key) + 2);
            sprintf(value, "%s=", key);
            if (putenv(value)) {
                return luaL_error(L, "unable to change environment");
            }
#else
            (void) unsetenv(key);
#endif
        }
    }
    lua_pushboolean(L, 1);
    return 1;
}


void find_env(lua_State * L)
{
    char *envitem, *envitem_orig;
    char *envkey;
    char **envpointer;
    envpointer = environ;
    lua_getglobal(L, "os");
    if (envpointer != NULL && lua_istable(L, -1)) {
        luaL_checkstack(L, 2, "out of stack space");
        lua_pushstring(L, "env");
        lua_newtable(L);
        while (*envpointer) {
            /* TODO: perhaps a memory leak here  */
            luaL_checkstack(L, 2, "out of stack space");
            envitem = xstrdup(*envpointer);
            envitem_orig = envitem;
            envkey = envitem;
            while (*envitem != '=') {
                envitem++;
            }
            *envitem = 0;
            envitem++;
            lua_pushstring(L, envkey);
            lua_pushstring(L, envitem);
            lua_rawset(L, -3);
            envpointer++;
            free(envitem_orig);
        }
        lua_rawset(L, -3);
    }
    lua_pop(L, 1);
}

static int ex_sleep(lua_State * L)
{
    lua_Number interval = luaL_checknumber(L, 1);
    lua_Number units = luaL_optnumber(L, 2, 1);
#ifdef WIN32
    Sleep(1e3 * interval / units);
#else                           /* assumes posix or bsd */
    usleep(1e6 * interval / units);
#endif
    return 0;
}



#ifdef WIN32
#  define _UTSNAME_LENGTH 65

/* Structure describing the system and machine.  */
struct utsname {
    char sysname[_UTSNAME_LENGTH];
    char nodename[_UTSNAME_LENGTH];
    char release[_UTSNAME_LENGTH];
    char version[_UTSNAME_LENGTH];
    char machine[_UTSNAME_LENGTH];
};

/*
 * Get name and information about current kernel.
 */
static int uname(struct utsname *uts)
{
    enum { WinNT, Win95, Win98, WinUnknown };
    OSVERSIONINFO osver;
    SYSTEM_INFO sysinfo;
    DWORD sLength;
    DWORD os = WinUnknown;

    memset(uts, 0, sizeof(*uts));

    osver.dwOSVersionInfoSize = sizeof(osver);
    GetVersionEx(&osver);
    GetSystemInfo(&sysinfo);

    switch (osver.dwPlatformId) {
    case VER_PLATFORM_WIN32_NT:        /* NT, Windows 2000 or Windows XP */
        if (osver.dwMajorVersion == 4)
            strcpy(uts->sysname, "Windows NT4x");       /* NT4x */
        else if (osver.dwMajorVersion <= 3)
            strcpy(uts->sysname, "Windows NT3x");       /* NT3x */
        else if (osver.dwMajorVersion == 5) {
            if (osver.dwMinorVersion == 0)
                strcpy(uts->sysname, "Windows 2000");   /* 2k */
            else if (osver.dwMinorVersion == 1)
                strcpy(uts->sysname, "Windows XP");     /* XP */
            else if (osver.dwMinorVersion == 2)
                strcpy(uts->sysname, "Windows Server 2003");    /* Server 2003 */
        } else if (osver.dwMajorVersion == 6) {
            /*
               if( osver.wProductType == VER_NT_WORKSTATION )
             */
            strcpy(uts->sysname, "Windows Vista");      /* Vista */
            /*
               else
               strcpy (uts->sysname, "Windows Server 2008"); 
             */
        }
        os = WinNT;
        break;

    case VER_PLATFORM_WIN32_WINDOWS:   /* Win95, Win98 or WinME */
        if ((osver.dwMajorVersion > 4) ||
            ((osver.dwMajorVersion == 4) && (osver.dwMinorVersion > 0))) {
            if (osver.dwMinorVersion >= 90)
                strcpy(uts->sysname, "Windows ME");     /* ME */
            else
                strcpy(uts->sysname, "Windows 98");     /* 98 */
            os = Win98;
        } else {
            strcpy(uts->sysname, "Windows 95"); /* 95 */
            os = Win95;
        }
        break;

    case VER_PLATFORM_WIN32s:  /* Windows 3.x */
        strcpy(uts->sysname, "Windows");
        break;

    default:                   /* anything else */
        strcpy(uts->sysname, "Windows");
        break;
    }

    sprintf(uts->version, "%ld.%02ld",
            osver.dwMajorVersion, osver.dwMinorVersion);

    if (osver.szCSDVersion[0] != '\0' &&
        (strlen(osver.szCSDVersion) + strlen(uts->version) + 1) <
        sizeof(uts->version)) {
        strcat(uts->version, " ");
        strcat(uts->version, osver.szCSDVersion);
    }

    sprintf(uts->release, "build %ld", osver.dwBuildNumber & 0xFFFF);

    switch (sysinfo.wProcessorArchitecture) {
    case PROCESSOR_ARCHITECTURE_PPC:
        strcpy(uts->machine, "ppc");
        break;
    case PROCESSOR_ARCHITECTURE_ALPHA:
        strcpy(uts->machine, "alpha");
        break;
    case PROCESSOR_ARCHITECTURE_MIPS:
        strcpy(uts->machine, "mips");
        break;
    case PROCESSOR_ARCHITECTURE_INTEL:
        /* 
         * dwProcessorType is only valid in Win95 and Win98 and WinME
         * wProcessorLevel is only valid in WinNT 
         */
        switch (os) {
        case Win95:
        case Win98:
            switch (sysinfo.dwProcessorType) {
            case PROCESSOR_INTEL_386:
            case PROCESSOR_INTEL_486:
            case PROCESSOR_INTEL_PENTIUM:
                sprintf(uts->machine, "i%ld", sysinfo.dwProcessorType);
                break;
            default:
                strcpy(uts->machine, "i386");
                break;
            }
            break;
        case WinNT:
            sprintf(uts->machine, "i%d86", sysinfo.wProcessorLevel);
            break;
        default:
            strcpy(uts->machine, "unknown");
            break;
        }
        break;
    default:
        strcpy(uts->machine, "unknown");
        break;
    }

    sLength = sizeof(uts->nodename) - 1;
    GetComputerName(uts->nodename, &sLength);
    return 0;
}
#endif


static int ex_uname(lua_State * L)
{
    struct utsname uts;
    if (uname(&uts) >= 0) {
        lua_newtable(L);
        lua_pushstring(L, uts.sysname);
        lua_setfield(L, -2, "sysname");
        lua_pushstring(L, uts.machine);
        lua_setfield(L, -2, "machine");
        lua_pushstring(L, uts.release);
        lua_setfield(L, -2, "release");
        lua_pushstring(L, uts.version);
        lua_setfield(L, -2, "version");
        lua_pushstring(L, uts.nodename);
        lua_setfield(L, -2, "nodename");
    } else {
        lua_pushnil(L);
    }
    return 1;
}


#if (! defined (WIN32))  && (! defined (__SUNOS__))
static int os_times(lua_State * L)
{
    struct tms r;
    (void) times(&r);
    lua_newtable(L);
    lua_pushnumber(L,
                   ((lua_Number) (r.tms_utime)) /
                   (lua_Number) sysconf(_SC_CLK_TCK));
    lua_setfield(L, -2, "utime");
    lua_pushnumber(L,
                   ((lua_Number) (r.tms_stime)) /
                   (lua_Number) sysconf(_SC_CLK_TCK));
    lua_setfield(L, -2, "stime");
    lua_pushnumber(L,
                   ((lua_Number) (r.tms_cutime)) /
                   (lua_Number) sysconf(_SC_CLK_TCK));
    lua_setfield(L, -2, "cutime");
    lua_pushnumber(L,
                   ((lua_Number) (r.tms_cstime)) /
                   (lua_Number) sysconf(_SC_CLK_TCK));
    lua_setfield(L, -2, "cstime");
    return 1;
}
#endif

#if ! defined (__SUNOS__)

#  if defined(_MSC_VER) || defined(_MSC_EXTENSIONS)
#    define DELTA_EPOCH_IN_MICROSECS  11644473600000000Ui64
#  else
#    define DELTA_EPOCH_IN_MICROSECS  11644473600000000ULL
#  endif

static int os_gettimeofday(lua_State * L)
{
    double v;
#  ifndef WIN32
    struct timeval tv;
    gettimeofday(&tv, NULL);
    v = (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
#  else
    FILETIME ft;
    unsigned __int64 tmpres = 0;

    GetSystemTimeAsFileTime(&ft);

    tmpres |= ft.dwHighDateTime;
    tmpres <<= 32;
    tmpres |= ft.dwLowDateTime;
    tmpres /= 10;
    tmpres -= DELTA_EPOCH_IN_MICROSECS; /*converting file time to unix epoch */
    v = (double) tmpres / 1000000.0;
#  endif
    lua_pushnumber(L, v);
    return 1;
}
#endif

static const char repl[] = "0123456789abcdefghijklmnopqrstuvwxyz";

static int dirs_made = 0;

#define MAXTRIES 36*36*36

char *do_mkdtemp(char *tmpl)
{
    int count;
    int value;
    char *xes = &tmpl[strlen(tmpl) - 6];
    /* this is not really all that random, but it will do */
    if (dirs_made == 0) {
        srand(time(NULL));
    }
    value = rand();
    for (count = 0; count < MAXTRIES; value += 8413, ++count) {
        int v = value;
        xes[0] = repl[v % 36];
        v /= 36;
        xes[1] = repl[v % 36];
        v /= 36;
        xes[2] = repl[v % 36];
        v /= 36;
        xes[3] = repl[v % 36];
        v /= 36;
        xes[4] = repl[v % 36];
        v /= 36;
        xes[5] = repl[v % 36];
        if (MKDIR(tmpl, S_IRUSR | S_IWUSR | S_IXUSR) >= 0) {
            dirs_made++;
            return tmpl;
        } else if (errno != EEXIST) {
            return NULL;
        }
    }
    return NULL;
}

static int os_tmpdir(lua_State * L)
{
    char *s, *tempdir;
    char *tmp = (char *) luaL_optstring(L, 1, "luatex.XXXXXX");
    if (tmp == NULL ||
        strlen(tmp) < 6 || (strcmp(tmp + strlen(tmp) - 6, "XXXXXX") != 0)) {
        lua_pushnil(L);
        lua_pushstring(L, "Invalid argument to os.tmpdir()");
        return 2;
    } else {
        tempdir = xstrdup(tmp);
    }
#ifdef HAVE_MKDTEMP
    s = mkdtemp(tempdir);
#else
    s = do_mkdtemp(tempdir);
#endif
    if (s == NULL) {
        int en = errno;         /* calls to Lua API may change this value */
        lua_pushnil(L);
        lua_pushfstring(L, "%s", strerror(en));
        return 2;
    } else {
        lua_pushstring(L, s);
        return 1;
    }
}


static int os_execute(lua_State * L)
{
    int allow = 0;
    int ret = 1;
    char *safecmd = NULL;
    char *cmdname = NULL;
    char *cmd = (char *) luaL_optstring(L, 1, NULL);

    if (shellenabledp <= 0) {
        lua_pushnil(L);
        lua_pushstring(L, "All command execution disabled.");
        return 2;
    }
    /* If restrictedshell == 0, any command is allowed. */
    if (restrictedshell == 0)
        allow = 1;
    else
        allow = shell_cmd_is_allowed(&cmd, &safecmd, &cmdname);

    if (allow == 1) {
        lua_pushinteger(L, system(cmd));
    } else if (allow == 2) {
        lua_pushinteger(L, system(safecmd));
    } else {
        lua_pushnil(L);
        ret = 2;
        if (allow == 0)
            lua_pushstring(L,
                           "Command execution disabled via shell_escape='p'");
        else                    /* allow == -1 */
            lua_pushstring(L, "Quoting error in system command line.");
    }
    if (safecmd)
        free(safecmd);
    if (cmdname)
        free(cmdname);
    return ret;
}


void open_oslibext(lua_State * L, int safer_option)
{

    find_env(L);

    lua_getglobal(L, "os");
    lua_pushcfunction(L, ex_sleep);
    lua_setfield(L, -2, "sleep");
    lua_pushliteral(L, OS_PLATTYPE);
    lua_setfield(L, -2, "type");
    lua_pushliteral(L, OS_PLATNAME);
    lua_setfield(L, -2, "name");
    lua_pushcfunction(L, ex_uname);
    lua_setfield(L, -2, "uname");
#if (! defined (WIN32))  && (! defined (__SUNOS__))
    lua_pushcfunction(L, os_times);
    lua_setfield(L, -2, "times");
#endif
#if ! defined (__SUNOS__)
    lua_pushcfunction(L, os_gettimeofday);
    lua_setfield(L, -2, "gettimeofday");
#endif

    if (!safer_option) {
        lua_pushcfunction(L, os_setenv);
        lua_setfield(L, -2, "setenv");
        lua_pushcfunction(L, os_exec);
        lua_setfield(L, -2, "exec");
        lua_pushcfunction(L, os_spawn);
        lua_setfield(L, -2, "spawn");
        lua_pushcfunction(L, os_execute);
        lua_setfield(L, -2, "execute");
        lua_pushcfunction(L, os_tmpdir);
        lua_setfield(L, -2, "tmpdir");
    }
    lua_pop(L, 1);              /* pop the table */
}