Codebase list fish / upstream/2.1.2+dfsg1 wildcard.cpp
upstream/2.1.2+dfsg1

Tree @upstream/2.1.2+dfsg1 (Download .tar.gz)

wildcard.cpp @upstream/2.1.2+dfsg1raw · history · 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
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
/** \file wildcard.c

Fish needs it's own globbing implementation to support
tab-expansion of globbed parameters. Also provides recursive
wildcards using **.

*/

#include "config.h"
#include <algorithm>
#include <stdlib.h>
#include <stdio.h>
#include <limits.h>
#include <wchar.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#include <errno.h>
#include <string.h>
#include <set>


#include "fallback.h"
#include "util.h"

#include "wutil.h"
#include "complete.h"
#include "common.h"
#include "wildcard.h"
#include "complete.h"
#include "reader.h"
#include "expand.h"
#include "exec.h"
#include <map>

/**
   This flag is set in the flags parameter of wildcard_expand if the
   call is part of a recursiv wildcard search. It is used to make sure
   that the contents of subdirectories are only searched once.
*/
#define WILDCARD_RECURSIVE 64

/**
   The maximum length of a filename token. This is a fallback value,
   an attempt to find the true value using patchconf is always made.
*/
#define MAX_FILE_LENGTH 1024

/**
   The command to run to get a description from a file suffix
*/
#define SUFFIX_CMD_STR L"mimedb 2>/dev/null -fd "

/**
   Description for generic executable
*/
#define COMPLETE_EXEC_DESC _( L"Executable" )
/**
   Description for link to executable
*/
#define COMPLETE_EXEC_LINK_DESC _( L"Executable link" )

/**
   Description for regular file
*/
#define COMPLETE_FILE_DESC _( L"File" )
/**
   Description for character device
*/
#define COMPLETE_CHAR_DESC _( L"Character device" )
/**
   Description for block device
*/
#define COMPLETE_BLOCK_DESC _( L"Block device" )
/**
   Description for fifo buffer
*/
#define COMPLETE_FIFO_DESC _( L"Fifo" )
/**
   Description for symlink
*/
#define COMPLETE_SYMLINK_DESC _( L"Symbolic link" )
/**
   Description for symlink
*/
#define COMPLETE_DIRECTORY_SYMLINK_DESC _( L"Symbolic link to directory" )
/**
   Description for Rotten symlink
*/
#define COMPLETE_ROTTEN_SYMLINK_DESC _( L"Rotten symbolic link" )
/**
   Description for symlink loop
*/
#define COMPLETE_LOOP_SYMLINK_DESC _( L"Symbolic link loop" )
/**
   Description for socket files
*/
#define COMPLETE_SOCKET_DESC _( L"Socket" )
/**
   Description for directories
*/
#define COMPLETE_DIRECTORY_DESC _( L"Directory" )

/** Hashtable containing all descriptions that describe an executable */
static std::map<wcstring, wcstring> suffix_map;


bool wildcard_has(const wchar_t *str, bool internal)
{
    if (!str)
    {
        debug(2, L"Got null string on line %d of file %s", __LINE__, __FILE__);
        return false;
    }

    if (internal)
    {
        for (; *str; str++)
        {
            if ((*str == ANY_CHAR) || (*str == ANY_STRING) || (*str == ANY_STRING_RECURSIVE))
                return true;
        }
    }
    else
    {
        wchar_t prev=0;
        for (; *str; str++)
        {
            if (((*str == L'*') || (*str == L'?')) && (prev != L'\\'))
                return true;
            prev = *str;
        }
    }

    return false;
}

/**
   Check whether the string str matches the wildcard string wc.

   \param str String to be matched.
   \param wc The wildcard.
   \param is_first Whether files beginning with dots should not be matched against wildcards.
*/
static bool wildcard_match_internal(const wchar_t *str, const wchar_t *wc, bool leading_dots_fail_to_match, bool is_first)
{
    if (*str == 0 && *wc==0)
        return true;

    /* Hackish fix for https://github.com/fish-shell/fish-shell/issues/270 . Prevent wildcards from matching . or .., but we must still allow literal matches. */
    if (leading_dots_fail_to_match && is_first && contains(str, L".", L".."))
    {
        /* The string is '.' or '..'. Return true if the wildcard exactly matches. */
        return ! wcscmp(str, wc);
    }

    if (*wc == ANY_STRING || *wc == ANY_STRING_RECURSIVE)
    {
        /* Ignore hidden file */
        if (leading_dots_fail_to_match && is_first && *str == L'.')
        {
            return false;
        }

        /* Try all submatches */
        do
        {
            if (wildcard_match_internal(str, wc+1, leading_dots_fail_to_match, false))
                return true;
        }
        while (*(str++) != 0);
        return false;
    }
    else if (*str == 0)
    {
        /*
          End of string, but not end of wildcard, and the next wildcard
          element is not a '*', so this is not a match.
        */
        return false;
    }

    if (*wc == ANY_CHAR)
    {
        if (is_first && *str == L'.')
        {
            return false;
        }

        return wildcard_match_internal(str+1, wc+1, leading_dots_fail_to_match, false);
    }

    if (*wc == *str)
        return wildcard_match_internal(str+1, wc+1, leading_dots_fail_to_match, false);

    return false;
}

/**
   Matches the string against the wildcard, and if the wildcard is a
   possible completion of the string, the remainder of the string is
   inserted into the out vector.
*/
static bool wildcard_complete_internal(const wcstring &orig,
                                       const wchar_t *str,
                                       const wchar_t *wc,
                                       bool is_first,
                                       const wchar_t *desc,
                                       wcstring(*desc_func)(const wcstring &),
                                       std::vector<completion_t> &out,
                                       expand_flags_t expand_flags,
                                       complete_flags_t flags)
{
    if (!wc || ! str || orig.empty())
    {
        debug(2, L"Got null string on line %d of file %s", __LINE__, __FILE__);
        return 0;
    }

    bool has_match = false;
    string_fuzzy_match_t fuzzy_match(fuzzy_match_exact);
    const bool at_end_of_wildcard = (*wc == L'\0');
    const wchar_t *completion_string = NULL;

    // Hack hack hack
    // Implement EXPAND_FUZZY_MATCH by short-circuiting everything if there are no remaining wildcards
    if ((expand_flags & EXPAND_FUZZY_MATCH) && ! at_end_of_wildcard && ! wildcard_has(wc, true))
    {
        string_fuzzy_match_t local_fuzzy_match = string_fuzzy_match_string(wc, str);
        if (local_fuzzy_match.type != fuzzy_match_none)
        {
            has_match = true;
            fuzzy_match = local_fuzzy_match;

            /* If we're not a prefix or exact match, then we need to replace the token. Note that in this case we're not going to call ourselves recursively, so these modified flags won't "leak" except into the completion. */
            if (match_type_requires_full_replacement(local_fuzzy_match.type))
            {
                flags |= COMPLETE_REPLACES_TOKEN;
                completion_string = orig.c_str();
            }
            else
            {
                /* Since we are not replacing the token, be careful to only store the part of the string after the wildcard */
                size_t wc_len = wcslen(wc);
                assert(wcslen(str) >= wc_len);
                completion_string = str + wcslen(wc);
            }
        }
    }

    /* Maybe we satisfied the wildcard normally */
    if (! has_match)
    {
        bool file_has_leading_dot = (is_first && str[0] == L'.');
        if (at_end_of_wildcard && ! file_has_leading_dot)
        {
            has_match = true;
            if (flags & COMPLETE_REPLACES_TOKEN)
            {
                completion_string = orig.c_str();
            }
            else
            {
                completion_string = str;
            }
        }
    }

    if (has_match)
    {
        /* Wildcard complete */
        assert(completion_string != NULL);
        wcstring out_completion = completion_string;
        wcstring out_desc = (desc ? desc : L"");

        size_t complete_sep_loc = out_completion.find(PROG_COMPLETE_SEP);
        if (complete_sep_loc != wcstring::npos)
        {
            /* This completion has an embedded description, do not use the generic description */
            out_desc.assign(out_completion, complete_sep_loc + 1, out_completion.size() - complete_sep_loc - 1);
            out_completion.resize(complete_sep_loc);
        }
        else
        {
            if (desc_func && !(expand_flags & EXPAND_NO_DESCRIPTIONS))
            {
                /*
                  A description generating function is specified, call
                  it. If it returns something, use that as the
                  description.
                */
                wcstring func_desc = desc_func(orig);
                if (! func_desc.empty())
                    out_desc = func_desc;
            }

        }

        /* Note: out_completion may be empty if the completion really is empty, e.g. tab-completing 'foo' when a file 'foo' exists. */
        append_completion(out, out_completion, out_desc, flags, fuzzy_match);
        return true;
    }

    if (*wc == ANY_STRING)
    {
        bool res=false;

        /* Ignore hidden file */
        if (is_first && str[0] == L'.')
            return false;

        /* Try all submatches */
        for (size_t i=0; str[i] != L'\0'; i++)
        {
            const size_t before_count = out.size();
            if (wildcard_complete_internal(orig, str + i, wc+1, false, desc, desc_func, out, expand_flags, flags))
            {
                res = true;
                
                /* #929: if the recursive call gives us a prefix match, just stop. This is sloppy - what we really want to do is say, once we've seen a match of a particular type, ignore all matches of that type further down the string, such that the wildcard produces the "minimal match." */
                bool has_prefix_match = false;
                const size_t after_count = out.size();
                for (size_t j = before_count; j < after_count; j++)
                {
                    if (out[j].match.type <= fuzzy_match_prefix)
                    {
                        has_prefix_match = true;
                        break;
                    }
                }
                if (has_prefix_match)
                    break;
            }
        }
        return res;

    }
    else if (*wc == ANY_CHAR || *wc == *str)
    {
        return wildcard_complete_internal(orig, str+1, wc+1, false, desc, desc_func, out, expand_flags, flags);
    }
    else if (towlower(*wc) == towlower(*str))
    {
        return wildcard_complete_internal(orig, str+1, wc+1, false, desc, desc_func, out, expand_flags, flags | COMPLETE_REPLACES_TOKEN);
    }
    return false;
}

bool wildcard_complete(const wcstring &str,
                       const wchar_t *wc,
                       const wchar_t *desc,
                       wcstring(*desc_func)(const wcstring &),
                       std::vector<completion_t> &out,
                       expand_flags_t expand_flags,
                       complete_flags_t flags)
{
    bool res;
    res =  wildcard_complete_internal(str, str.c_str(), wc, true, desc, desc_func, out, expand_flags, flags);
    return res;
}


bool wildcard_match(const wcstring &str, const wcstring &wc, bool leading_dots_fail_to_match)
{
    return wildcard_match_internal(str.c_str(), wc.c_str(), leading_dots_fail_to_match, true /* first */);
}

/**
   Creates a path from the specified directory and filename.
*/
static wcstring make_path(const wcstring &base_dir, const wcstring &name)
{
    return base_dir + name;
}

/**
   Return a description of a file based on its suffix. This function
   does not perform any caching, it directly calls the mimedb command
   to do a lookup.
 */
static wcstring complete_get_desc_suffix_internal(const wcstring &suff)
{

    wcstring cmd = wcstring(SUFFIX_CMD_STR) + suff;

    wcstring_list_t lst;
    wcstring desc;

    if (exec_subshell(cmd, lst, false /* do not apply exit status */) != -1)
    {
        if (! lst.empty())
        {
            const wcstring & ln = lst.at(0);
            if (ln.size() > 0 && ln != L"unknown")
            {
                desc = ln;
                /*
                  I have decided I prefer to have the description
                  begin in uppercase and the whole universe will just
                  have to accept it. Hah!
                */
                desc[0]=towupper(desc[0]);
            }
        }
    }

    if (desc.empty())
    {
        desc = COMPLETE_FILE_DESC;
    }

    suffix_map[suff] = desc.c_str();
    return desc;
}


/**
   Use the mimedb command to look up a description for a given suffix
*/
static wcstring complete_get_desc_suffix(const wchar_t *suff_orig)
{

    size_t len;
    wchar_t *suff;
    wchar_t *pos;
    wchar_t *tmp;

    len = wcslen(suff_orig);

    if (len == 0)
        return COMPLETE_FILE_DESC;

    suff = wcsdup(suff_orig);

    /*
      Drop characters that are commonly used as backup suffixes from the suffix
    */
    for (pos=suff; *pos; pos++)
    {
        if (wcschr(L"?;#~@&", *pos))
        {
            *pos=0;
            break;
        }
    }

    tmp = escape(suff, 1);
    free(suff);
    suff = tmp;

    std::map<wcstring, wcstring>::iterator iter = suffix_map.find(suff);
    wcstring desc;
    if (iter != suffix_map.end())
    {
        desc = iter->second;
    }
    else
    {
        desc = complete_get_desc_suffix_internal(suff);
    }

    free(suff);

    return desc;
}


/**
   Obtain a description string for the file specified by the filename.

   The returned value is a string constant and should not be free'd.

   \param filename The file for which to find a description string
   \param lstat_res The result of calling lstat on the file
   \param lbuf The struct buf output of calling lstat on the file
   \param stat_res The result of calling stat on the file
   \param buf The struct buf output of calling stat on the file
   \param err The errno value after a failed stat call on the file.
*/

static wcstring file_get_desc(const wcstring &filename,
                              int lstat_res,
                              struct stat lbuf,
                              int stat_res,
                              struct stat buf,
                              int err)
{
    const wchar_t *suffix;

    if (!lstat_res)
    {
        if (S_ISLNK(lbuf.st_mode))
        {
            if (!stat_res)
            {
                if (S_ISDIR(buf.st_mode))
                {
                    return COMPLETE_DIRECTORY_SYMLINK_DESC;
                }
                else
                {

                    if ((buf.st_mode & S_IXUSR) ||
                            (buf.st_mode & S_IXGRP) ||
                            (buf.st_mode & S_IXOTH))
                    {

                        if (waccess(filename, X_OK) == 0)
                        {
                            /*
                              Weird group permissions and other such
                              issues make it non-trivial to find out
                              if we can actually execute a file using
                              the result from stat. It is much safer
                              to use the access function, since it
                              tells us exactly what we want to know.
                            */
                            return COMPLETE_EXEC_LINK_DESC;
                        }
                    }
                }

                return COMPLETE_SYMLINK_DESC;

            }
            else
            {
                switch (err)
                {
                    case ENOENT:
                    {
                        return COMPLETE_ROTTEN_SYMLINK_DESC;
                    }

                    case ELOOP:
                    {
                        return COMPLETE_LOOP_SYMLINK_DESC;
                    }
                }
                /*
                  On unknown errors we do nothing. The file will be
                  given the default 'File' description or one based on the suffix.
                */
            }

        }
        else if (S_ISCHR(buf.st_mode))
        {
            return COMPLETE_CHAR_DESC;
        }
        else if (S_ISBLK(buf.st_mode))
        {
            return COMPLETE_BLOCK_DESC;
        }
        else if (S_ISFIFO(buf.st_mode))
        {
            return COMPLETE_FIFO_DESC;
        }
        else if (S_ISSOCK(buf.st_mode))
        {
            return COMPLETE_SOCKET_DESC;
        }
        else if (S_ISDIR(buf.st_mode))
        {
            return COMPLETE_DIRECTORY_DESC;
        }
        else
        {
            if ((buf.st_mode & S_IXUSR) ||
                    (buf.st_mode & S_IXGRP) ||
                    (buf.st_mode & S_IXOTH))
            {

                if (waccess(filename, X_OK) == 0)
                {
                    /*
                      Weird group permissions and other such issues
                      make it non-trivial to find out if we can
                      actually execute a file using the result from
                      stat. It is much safer to use the access
                      function, since it tells us exactly what we want
                      to know.
                    */
                    return COMPLETE_EXEC_DESC;
                }
            }
        }
    }

    suffix = wcsrchr(filename.c_str(), L'.');
    if (suffix != 0 && !wcsrchr(suffix, L'/'))
    {
        return complete_get_desc_suffix(suffix);
    }

    return COMPLETE_FILE_DESC ;
}


/**
   Add the specified filename if it matches the specified wildcard.

   If the filename matches, first get the description of the specified
   filename. If this is a regular file, append the filesize to the
   description.

   \param list the list to add he completion to
   \param fullname the full filename of the file
   \param completion the completion part of the file name
   \param wc the wildcard to match against
   \param is_cmd whether we are performing command completion
*/
static void wildcard_completion_allocate(std::vector<completion_t> &list,
        const wcstring &fullname,
        const wcstring &completion,
        const wchar_t *wc,
        expand_flags_t expand_flags)
{
    struct stat buf, lbuf;
    wcstring sb;
    wcstring munged_completion;

    int flags = 0;
    int stat_res, lstat_res;
    int stat_errno=0;

    long long sz;

    /*
      If the file is a symlink, we need to stat both the file itself
      _and_ the destination file. But we try to avoid this with
      non-symlinks by first doing an lstat, and if the file is not a
      link we copy the results over to the regular stat buffer.
    */
    if ((lstat_res = lwstat(fullname, &lbuf)))
    {
        /* lstat failed! */
        sz=-1;
        stat_res = lstat_res;
    }
    else
    {
        if (S_ISLNK(lbuf.st_mode))
        {

            if ((stat_res = wstat(fullname, &buf)))
            {
                sz=-1;
            }
            else
            {
                sz = (long long)buf.st_size;
            }

            /*
              In order to differentiate between e.g. rotten symlinks
              and symlink loops, we also need to know the error status of wstat.
            */
            stat_errno = errno;
        }
        else
        {
            stat_res = lstat_res;
            memcpy(&buf, &lbuf, sizeof(struct stat));
            sz = (long long)buf.st_size;
        }
    }


    bool wants_desc = !(expand_flags & EXPAND_NO_DESCRIPTIONS);
    wcstring desc;
    if (wants_desc)
        desc = file_get_desc(fullname, lstat_res, lbuf, stat_res, buf, stat_errno);

    if (sz >= 0 && S_ISDIR(buf.st_mode))
    {
        flags |= COMPLETE_NO_SPACE;
        munged_completion = completion;
        munged_completion.push_back(L'/');
        if (wants_desc)
            sb.append(desc);
    }
    else
    {
        if (wants_desc)
        {
            if (! desc.empty())
            {
                sb.append(desc);
                sb.append(L", ");
            }
            sb.append(format_size(sz));
        }
    }

    const wcstring &completion_to_use = munged_completion.empty() ? completion : munged_completion;
    wildcard_complete(completion_to_use, wc, sb.c_str(), NULL, list, expand_flags, flags);
}

/**
  Test if the file specified by the given filename matches the
  expansion flags specified. flags can be a combination of
  EXECUTABLES_ONLY and DIRECTORIES_ONLY.
*/
static bool test_flags(const wchar_t *filename, expand_flags_t flags)
{
    if (flags & DIRECTORIES_ONLY)
    {
        struct stat buf;
        if (wstat(filename, &buf) == -1)
        {
            return false;
        }

        if (!S_ISDIR(buf.st_mode))
        {
            return false;
        }
    }


    if (flags & EXECUTABLES_ONLY)
    {
        if (waccess(filename, X_OK) != 0)
            return false;
    }

    return true;
}

/** Appends a completion to the completion list, if the string is missing from the set. */
static void insert_completion_if_missing(const wcstring &str, std::vector<completion_t> &out, std::set<wcstring> &completion_set)
{
    if (completion_set.insert(str).second)
        append_completion(out, str);
}

/**
   The real implementation of wildcard expansion is in this
   function. Other functions are just wrappers around this one.

   This function traverses the relevant directory tree looking for
   matches, and recurses when needed to handle wildcrards spanning
   multiple components and recursive wildcards.

   Because this function calls itself recursively with substrings,
   it's important that the parameters be raw pointers instead of wcstring,
   which would be too expensive to construct for all substrings.
 */
static int wildcard_expand_internal(const wchar_t *wc,
                                    const wchar_t * const base_dir,
                                    expand_flags_t flags,
                                    std::vector<completion_t> &out,
                                    std::set<wcstring> &completion_set,
                                    std::set<file_id_t> &visited_files)
{

    /* Variables for traversing a directory */
    DIR *dir;

    /* The result returned */
    int res = 0;

    /* Variables for testing for presense of recursive wildcards */
    const wchar_t *wc_recursive;
    bool is_recursive;

    /* Slightly mangled version of base_dir */
    const wchar_t *dir_string;

    //  debug( 3, L"WILDCARD_EXPAND %ls in %ls", wc, base_dir );

    if (is_main_thread() ? reader_interrupted() : reader_thread_job_is_stale())
    {
        return -1;
    }

    if (!wc || !base_dir)
    {
        debug(2, L"Got null string on line %d of file %s", __LINE__, __FILE__);
        return 0;
    }

    const size_t base_dir_len = wcslen(base_dir);

    if (flags & ACCEPT_INCOMPLETE)
    {
        /*
           Avoid excessive number of returned matches for wc ending with a *
        */
        size_t len = wcslen(wc);
        if (len > 0 && (wc[len-1]==ANY_STRING))
        {
            wchar_t * foo = wcsdup(wc);
            foo[len-1]=0;
            int res = wildcard_expand_internal(foo, base_dir, flags, out, completion_set, visited_files);
            free(foo);
            return res;
        }
    }

    /* Initialize various variables */

    dir_string = (base_dir[0] == L'\0') ? L"." : base_dir;

    if (!(dir = wopendir(dir_string)))
    {
        return 0;
    }

    /* Points to the end of the current wildcard segment */
    const wchar_t * const wc_end = wcschr(wc,L'/');

    /*
      Test for recursive match string in current segment
    */
    wc_recursive = wcschr(wc, ANY_STRING_RECURSIVE);
    is_recursive = (wc_recursive && (!wc_end || wc_recursive < wc_end));

    /*
      Is this segment of the wildcard the last?
    */
    if (!wc_end)
    {
        /*
          Wildcard segment is the last segment,

          Insert all matching files/directories
        */
        if (wc[0]=='\0')
        {
            /*
              The last wildcard segment is empty. Insert everything if
              completing, the directory itself otherwise.
            */
            if (flags & ACCEPT_INCOMPLETE)
            {
                wcstring next;
                while (wreaddir(dir, next))
                {
                    if (next[0] != L'.')
                    {
                        wcstring long_name = make_path(base_dir, next);

                        if (test_flags(long_name.c_str(), flags))
                        {
                            wildcard_completion_allocate(out, long_name, next, L"", flags);
                        }
                    }
                }
            }
            else
            {
                res = 1;
                insert_completion_if_missing(base_dir, out, completion_set);
            }
        }
        else
        {
            /* This is the last wildcard segment, and it is not empty. Match files/directories. */
            wcstring name_str;
            while (wreaddir(dir, name_str))
            {
                if (flags & ACCEPT_INCOMPLETE)
                {

                    const wcstring long_name = make_path(base_dir, name_str);

                    /* Test for matches before stating file, so as to minimize the number of calls to the much slower stat function. The only expand flag we care about is EXPAND_FUZZY_MATCH; we have no complete flags. */
                    std::vector<completion_t> test;
                    if (wildcard_complete(name_str, wc, L"", NULL, test, flags & EXPAND_FUZZY_MATCH, 0))
                    {
                        if (test_flags(long_name.c_str(), flags))
                        {
                            wildcard_completion_allocate(out, long_name, name_str, wc, flags);

                        }
                    }
                }
                else
                {
                    if (wildcard_match(name_str, wc, true /* skip files with leading dots */))
                    {
                        const wcstring long_name = make_path(base_dir, name_str);
                        int skip = 0;

                        if (is_recursive)
                        {
                            /*
                              In recursive mode, we are only
                              interested in adding files -directories
                              will be added in the next pass.
                            */
                            struct stat buf;
                            if (!wstat(long_name, &buf))
                            {
                                skip = S_ISDIR(buf.st_mode);
                            }
                        }
                        if (! skip)
                        {
                            insert_completion_if_missing(long_name, out, completion_set);
                        }
                        res = 1;
                    }
                }
            }
        }
    }

    if (wc_end || is_recursive)
    {
        /*
          Wilcard segment is not the last segment.  Recursively call
          wildcard_expand for all matching subdirectories.
        */

        /*
          In recursive mode, we look through the directory twice. If
          so, this rewind is needed.
        */
        rewinddir(dir);

        /*
          wc_str is the part of the wildcarded string from the
          beginning to the first slash
        */
        const wcstring wc_str = wcstring(wc, wc_end ? wc_end - wc : wcslen(wc));

        /* new_dir is a scratch area containing the full path to a file/directory we are iterating over */
        wcstring new_dir = base_dir;

        wcstring name_str;
        while (wreaddir(dir, name_str))
        {
            /*
              Test if the file/directory name matches the whole
              wildcard element, i.e. regular matching.
            */
            int whole_match = wildcard_match(name_str, wc_str, true /* ignore leading dots */);
            int partial_match = 0;

            /*
               If we are doing recursive matching, also check if this
               directory matches the part up to the recusrive
               wildcard, if so, then we can search all subdirectories
               for matches.
            */
            if (is_recursive)
            {
                const wchar_t *end = wcschr(wc, ANY_STRING_RECURSIVE);
                wchar_t *wc_sub = wcsndup(wc, end-wc+1);
                partial_match = wildcard_match(name_str, wc_sub, true /* ignore leading dots */);
                free(wc_sub);
            }

            if (whole_match || partial_match)
            {
                struct stat buf;
                int new_res;

                // new_dir is base_dir + some other path components
                // Replace everything after base_dir with the new path component
                new_dir.replace(base_dir_len, wcstring::npos, name_str);

                int stat_res = wstat(new_dir, &buf);

                if (!stat_res)
                {
                    // Insert a "file ID" into visited_files
                    // If the insertion fails, we've already visited this file (i.e. a symlink loop)
                    // If we're not recursive, insert anyways (in case we loop back around in a future recursive segment), but continue on; the idea being that literal path components should still work
                    const file_id_t file_id(buf.st_dev, buf.st_ino);
                    if (S_ISDIR(buf.st_mode) && (visited_files.insert(file_id).second || ! is_recursive))
                    {
                        new_dir.push_back(L'/');

                        /*
                          Regular matching
                        */
                        if (whole_match)
                        {
                            const wchar_t *new_wc = L"";
                            if (wc_end)
                            {
                                new_wc=wc_end+1;
                                /*
                                  Accept multiple '/' as a single direcotry separator
                                */
                                while (*new_wc==L'/')
                                {
                                    new_wc++;
                                }
                            }

                            new_res = wildcard_expand_internal(new_wc,
                                                               new_dir.c_str(),
                                                               flags,
                                                               out,
                                                               completion_set,
                                                               visited_files);

                            if (new_res == -1)
                            {
                                res = -1;
                                break;
                            }
                            res |= new_res;

                        }

                        /*
                          Recursive matching
                        */
                        if (partial_match)
                        {

                            new_res = wildcard_expand_internal(wcschr(wc, ANY_STRING_RECURSIVE),
                                                               new_dir.c_str(),
                                                               flags | WILDCARD_RECURSIVE,
                                                               out,
                                                               completion_set,
                                                               visited_files);

                            if (new_res == -1)
                            {
                                res = -1;
                                break;
                            }
                            res |= new_res;

                        }
                    }
                }
            }
        }
    }
    closedir(dir);

    return res;
}


int wildcard_expand(const wchar_t *wc,
                    const wchar_t *base_dir,
                    expand_flags_t flags,
                    std::vector<completion_t> &out)
{
    size_t c = out.size();

    /* Make a set of used completion strings so we can do fast membership tests inside wildcard_expand_internal. Otherwise wildcards like '**' are very slow, because we end up with an N^2 membership test.
    */
    std::set<wcstring> completion_set;
    for (std::vector<completion_t>::const_iterator iter = out.begin(); iter != out.end(); ++iter)
    {
        completion_set.insert(iter->completion);
    }

    std::set<file_id_t> visited_files;
    int res = wildcard_expand_internal(wc, base_dir, flags, out, completion_set, visited_files);

    if (flags & ACCEPT_INCOMPLETE)
    {
        wcstring wc_base;
        const wchar_t *wc_base_ptr = wcsrchr(wc, L'/');
        if (wc_base_ptr)
        {
            wc_base = wcstring(wc, (wc_base_ptr-wc)+1);
        }

        for (size_t i=c; i<out.size(); i++)
        {
            completion_t &c = out.at(i);

            if (c.flags & COMPLETE_REPLACES_TOKEN)
            {
                c.completion = format_string(L"%ls%ls%ls", base_dir, wc_base.c_str(), c.completion.c_str());
            }
        }
    }
    return res;
}

int wildcard_expand_string(const wcstring &wc, const wcstring &base_dir, expand_flags_t flags, std::vector<completion_t> &outputs)
{
    // PCA: not convinced this temporary variable is really necessary
    std::vector<completion_t> lst;
    int res = wildcard_expand(wc.c_str(), base_dir.c_str(), flags, lst);
    outputs.insert(outputs.end(), lst.begin(), lst.end());
    return res;
}