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 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397
|
/* redir.c -- Functions to perform input and output redirection. */
/* Copyright (C) 1997-2012 Free Software Foundation, Inc.
This file is part of GNU Bash, the Bourne Again SHell.
Bash 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 3 of the License, or
(at your option) any later version.
Bash 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with Bash. If not, see <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#if !defined (__GNUC__) && !defined (HAVE_ALLOCA_H) && defined (_AIX)
#pragma alloca
#endif /* _AIX && RISC6000 && !__GNUC__ */
#include <stdio.h>
#include "bashtypes.h"
#if !defined (_MINIX) && defined (HAVE_SYS_FILE_H)
# include <sys/file.h>
#endif
#include "filecntl.h"
#include "posixstat.h"
#if defined (HAVE_UNISTD_H)
# include <unistd.h>
#endif
#include <errno.h>
#if !defined (errno)
extern int errno;
#endif
#include "bashansi.h"
#include "bashintl.h"
#include "memalloc.h"
#define NEED_FPURGE_DECL
#include "shell.h"
#include "flags.h"
#include "execute_cmd.h"
#include "redir.h"
#if defined (BUFFERED_INPUT)
# include "input.h"
#endif
#define SHELL_FD_BASE 10
int expanding_redir;
extern int posixly_correct;
extern int last_command_exit_value;
extern int executing_builtin;
extern REDIRECT *redirection_undo_list;
extern REDIRECT *exec_redirection_undo_list;
/* Static functions defined and used in this file. */
static void add_exec_redirect __P((REDIRECT *));
static int add_undo_redirect __P((int, enum r_instruction, int));
static int add_undo_close_redirect __P((int));
static int expandable_redirection_filename __P((REDIRECT *));
static int stdin_redirection __P((enum r_instruction, int));
static int undoablefd __P((int));
static int do_redirection_internal __P((REDIRECT *, int));
static int write_here_document __P((int, WORD_DESC *));
static int write_here_string __P((int, WORD_DESC *));
static int here_document_to_fd __P((WORD_DESC *, enum r_instruction));
static int redir_special_open __P((int, char *, int, int, enum r_instruction));
static int noclobber_open __P((char *, int, int, enum r_instruction));
static int redir_open __P((char *, int, int, enum r_instruction));
static int redir_varassign __P((REDIRECT *, int));
static int redir_varvalue __P((REDIRECT *));
/* Spare redirector used when translating [N]>&WORD[-] or [N]<&WORD[-] to
a new redirection and when creating the redirection undo list. */
static REDIRECTEE rd;
/* Set to errno when a here document cannot be created for some reason.
Used to print a reasonable error message. */
static int heredoc_errno;
#define REDIRECTION_ERROR(r, e, fd) \
do { \
if ((r) < 0) \
{ \
if (fd >= 0) \
close (fd); \
last_command_exit_value = EXECUTION_FAILURE;\
return ((e) == 0 ? EINVAL : (e));\
} \
} while (0)
void
redirection_error (temp, error)
REDIRECT *temp;
int error;
{
char *filename, *allocname;
int oflags;
allocname = 0;
if (temp->rflags & REDIR_VARASSIGN)
filename = allocname = savestring (temp->redirector.filename->word);
else if (temp->redirector.dest < 0)
/* This can happen when read_token_word encounters overflow, like in
exec 4294967297>x */
filename = _("file descriptor out of range");
#ifdef EBADF
/* This error can never involve NOCLOBBER */
else if (error != NOCLOBBER_REDIRECT && temp->redirector.dest >= 0 && error == EBADF)
{
/* If we're dealing with two file descriptors, we have to guess about
which one is invalid; in the cases of r_{duplicating,move}_input and
r_{duplicating,move}_output we're here because dup2() failed. */
switch (temp->instruction)
{
case r_duplicating_input:
case r_duplicating_output:
case r_move_input:
case r_move_output:
filename = allocname = itos (temp->redirectee.dest);
break;
case r_duplicating_input_word:
if (temp->redirector.dest == 0) /* Guess */
filename = temp->redirectee.filename->word; /* XXX */
else
filename = allocname = itos (temp->redirector.dest);
break;
case r_duplicating_output_word:
if (temp->redirector.dest == 1) /* Guess */
filename = temp->redirectee.filename->word; /* XXX */
else
filename = allocname = itos (temp->redirector.dest);
break;
default:
filename = allocname = itos (temp->redirector.dest);
break;
}
}
#endif
else if (expandable_redirection_filename (temp))
{
expandable_filename:
oflags = temp->redirectee.filename->flags;
if (posixly_correct && interactive_shell == 0)
temp->redirectee.filename->flags |= W_NOGLOB;
temp->redirectee.filename->flags |= W_NOCOMSUB;
filename = allocname = redirection_expand (temp->redirectee.filename);
temp->redirectee.filename->flags = oflags;
if (filename == 0)
filename = temp->redirectee.filename->word;
}
else if (temp->redirectee.dest < 0)
filename = _("file descriptor out of range");
else
filename = allocname = itos (temp->redirectee.dest);
switch (error)
{
case AMBIGUOUS_REDIRECT:
internal_error (_("%s: ambiguous redirect"), filename);
break;
case NOCLOBBER_REDIRECT:
internal_error (_("%s: cannot overwrite existing file"), filename);
break;
#if defined (RESTRICTED_SHELL)
case RESTRICTED_REDIRECT:
internal_error (_("%s: restricted: cannot redirect output"), filename);
break;
#endif /* RESTRICTED_SHELL */
case HEREDOC_REDIRECT:
internal_error (_("cannot create temp file for here-document: %s"), strerror (heredoc_errno));
break;
case BADVAR_REDIRECT:
internal_error (_("%s: cannot assign fd to variable"), filename);
break;
default:
internal_error ("%s: %s", filename, strerror (error));
break;
}
FREE (allocname);
}
/* Perform the redirections on LIST. If flags & RX_ACTIVE, then actually
make input and output file descriptors, otherwise just do whatever is
necessary for side effecting. flags & RX_UNDOABLE says to remember
how to undo the redirections later, if non-zero. If flags & RX_CLEXEC
is non-zero, file descriptors opened in do_redirection () have their
close-on-exec flag set. */
int
do_redirections (list, flags)
REDIRECT *list;
int flags;
{
int error;
REDIRECT *temp;
if (flags & RX_UNDOABLE)
{
if (redirection_undo_list)
{
dispose_redirects (redirection_undo_list);
redirection_undo_list = (REDIRECT *)NULL;
}
if (exec_redirection_undo_list)
dispose_exec_redirects ();
}
for (temp = list; temp; temp = temp->next)
{
error = do_redirection_internal (temp, flags);
if (error)
{
redirection_error (temp, error);
return (error);
}
}
return (0);
}
/* Return non-zero if the redirection pointed to by REDIRECT has a
redirectee.filename that can be expanded. */
static int
expandable_redirection_filename (redirect)
REDIRECT *redirect;
{
switch (redirect->instruction)
{
case r_output_direction:
case r_appending_to:
case r_input_direction:
case r_inputa_direction:
case r_err_and_out:
case r_append_err_and_out:
case r_input_output:
case r_output_force:
case r_duplicating_input_word:
case r_duplicating_output_word:
case r_move_input_word:
case r_move_output_word:
return 1;
default:
return 0;
}
}
/* Expand the word in WORD returning a string. If WORD expands to
multiple words (or no words), then return NULL. */
char *
redirection_expand (word)
WORD_DESC *word;
{
char *result;
WORD_LIST *tlist1, *tlist2;
WORD_DESC *w;
int old;
w = copy_word (word);
if (posixly_correct)
w->flags |= W_NOSPLIT;
tlist1 = make_word_list (w, (WORD_LIST *)NULL);
expanding_redir = 1;
/* Now that we've changed the variable search order to ignore the temp
environment, see if we need to change the cached IFS values. */
sv_ifs ("IFS");
tlist2 = expand_words_no_vars (tlist1);
expanding_redir = 0;
/* Now we need to change the variable search order back to include the temp
environment. We force the temp environment search by forcing
executing_builtin to 1. This is what makes `read' get the right values
for the IFS-related cached variables, for example. */
old = executing_builtin;
executing_builtin = 1;
sv_ifs ("IFS");
executing_builtin = old;
dispose_words (tlist1);
if (tlist2 == 0 || tlist2->next)
{
/* We expanded to no words, or to more than a single word.
Dispose of the word list and return NULL. */
if (tlist2)
dispose_words (tlist2);
return ((char *)NULL);
}
result = string_list (tlist2); /* XXX savestring (tlist2->word->word)? */
dispose_words (tlist2);
return (result);
}
static int
write_here_string (fd, redirectee)
int fd;
WORD_DESC *redirectee;
{
char *herestr;
int herelen, n, e, old;
expanding_redir = 1;
/* Now that we've changed the variable search order to ignore the temp
environment, see if we need to change the cached IFS values. */
sv_ifs ("IFS");
herestr = expand_string_to_string (redirectee->word, 0);
expanding_redir = 0;
/* Now we need to change the variable search order back to include the temp
environment. We force the temp environment search by forcing
executing_builtin to 1. This is what makes `read' get the right values
for the IFS-related cached variables, for example. */
old = executing_builtin;
executing_builtin = 1;
sv_ifs ("IFS");
executing_builtin = old;
herelen = STRLEN (herestr);
n = write (fd, herestr, herelen);
if (n == herelen)
{
n = write (fd, "\n", 1);
herelen = 1;
}
e = errno;
FREE (herestr);
if (n != herelen)
{
if (e == 0)
e = ENOSPC;
return e;
}
return 0;
}
/* Write the text of the here document pointed to by REDIRECTEE to the file
descriptor FD, which is already open to a temp file. Return 0 if the
write is successful, otherwise return errno. */
static int
write_here_document (fd, redirectee)
int fd;
WORD_DESC *redirectee;
{
char *document;
int document_len, fd2, old;
FILE *fp;
register WORD_LIST *t, *tlist;
/* Expand the text if the word that was specified had
no quoting. The text that we expand is treated
exactly as if it were surrounded by double quotes. */
if (redirectee->flags & W_QUOTED)
{
document = redirectee->word;
document_len = strlen (document);
/* Set errno to something reasonable if the write fails. */
if (write (fd, document, document_len) < document_len)
{
if (errno == 0)
errno = ENOSPC;
return (errno);
}
else
return 0;
}
expanding_redir = 1;
/* Now that we've changed the variable search order to ignore the temp
environment, see if we need to change the cached IFS values. */
sv_ifs ("IFS");
tlist = expand_string (redirectee->word, Q_HERE_DOCUMENT);
expanding_redir = 0;
/* Now we need to change the variable search order back to include the temp
environment. We force the temp environment search by forcing
executing_builtin to 1. This is what makes `read' get the right values
for the IFS-related cached variables, for example. */
old = executing_builtin;
executing_builtin = 1;
sv_ifs ("IFS");
executing_builtin = old;
if (tlist)
{
/* Try using buffered I/O (stdio) and writing a word
at a time, letting stdio do the work of buffering
for us rather than managing our own strings. Most
stdios are not particularly fast, however -- this
may need to be reconsidered later. */
if ((fd2 = dup (fd)) < 0 || (fp = fdopen (fd2, "w")) == NULL)
{
if (fd2 >= 0)
close (fd2);
return (errno);
}
errno = 0;
for (t = tlist; t; t = t->next)
{
/* This is essentially the body of
string_list_internal expanded inline. */
document = t->word->word;
document_len = strlen (document);
if (t != tlist)
putc (' ', fp); /* separator */
fwrite (document, document_len, 1, fp);
if (ferror (fp))
{
if (errno == 0)
errno = ENOSPC;
fd2 = errno;
fclose(fp);
dispose_words (tlist);
return (fd2);
}
}
dispose_words (tlist);
if (fclose (fp) != 0)
{
if (errno == 0)
errno = ENOSPC;
return (errno);
}
}
return 0;
}
/* Create a temporary file holding the text of the here document pointed to
by REDIRECTEE, and return a file descriptor open for reading to the temp
file. Return -1 on any error, and make sure errno is set appropriately. */
static int
here_document_to_fd (redirectee, ri)
WORD_DESC *redirectee;
enum r_instruction ri;
{
char *filename;
int r, fd, fd2;
fd = sh_mktmpfd ("sh-thd", MT_USERANDOM|MT_USETMPDIR, &filename);
/* If we failed for some reason other than the file existing, abort */
if (fd < 0)
{
FREE (filename);
return (fd);
}
errno = r = 0; /* XXX */
/* write_here_document returns 0 on success, errno on failure. */
if (redirectee->word)
r = (ri != r_reading_string) ? write_here_document (fd, redirectee)
: write_here_string (fd, redirectee);
if (r)
{
close (fd);
unlink (filename);
free (filename);
errno = r;
return (-1);
}
/* In an attempt to avoid races, we close the first fd only after opening
the second. */
/* Make the document really temporary. Also make it the input. */
fd2 = open (filename, O_RDONLY|O_BINARY, 0600);
if (fd2 < 0)
{
r = errno;
unlink (filename);
free (filename);
close (fd);
errno = r;
return -1;
}
close (fd);
if (unlink (filename) < 0)
{
r = errno;
close (fd2);
free (filename);
errno = r;
return (-1);
}
free (filename);
return (fd2);
}
#define RF_DEVFD 1
#define RF_DEVSTDERR 2
#define RF_DEVSTDIN 3
#define RF_DEVSTDOUT 4
#define RF_DEVTCP 5
#define RF_DEVUDP 6
/* A list of pattern/value pairs for filenames that the redirection
code handles specially. */
static STRING_INT_ALIST _redir_special_filenames[] = {
#if !defined (HAVE_DEV_FD)
{ "/dev/fd/[0-9]*", RF_DEVFD },
#endif
#if !defined (HAVE_DEV_STDIN)
{ "/dev/stderr", RF_DEVSTDERR },
{ "/dev/stdin", RF_DEVSTDIN },
{ "/dev/stdout", RF_DEVSTDOUT },
#endif
#if defined (NETWORK_REDIRECTIONS)
{ "/dev/tcp/*/*", RF_DEVTCP },
{ "/dev/udp/*/*", RF_DEVUDP },
#endif
{ (char *)NULL, -1 }
};
static int
redir_special_open (spec, filename, flags, mode, ri)
int spec;
char *filename;
int flags, mode;
enum r_instruction ri;
{
int fd;
#if !defined (HAVE_DEV_FD)
intmax_t lfd;
#endif
fd = -1;
switch (spec)
{
#if !defined (HAVE_DEV_FD)
case RF_DEVFD:
if (all_digits (filename+8) && legal_number (filename+8, &lfd) && lfd == (int)lfd)
{
fd = lfd;
fd = fcntl (fd, F_DUPFD, SHELL_FD_BASE);
}
else
fd = AMBIGUOUS_REDIRECT;
break;
#endif
#if !defined (HAVE_DEV_STDIN)
case RF_DEVSTDIN:
fd = fcntl (0, F_DUPFD, SHELL_FD_BASE);
break;
case RF_DEVSTDOUT:
fd = fcntl (1, F_DUPFD, SHELL_FD_BASE);
break;
case RF_DEVSTDERR:
fd = fcntl (2, F_DUPFD, SHELL_FD_BASE);
break;
#endif
#if defined (NETWORK_REDIRECTIONS)
case RF_DEVTCP:
case RF_DEVUDP:
#if defined (HAVE_NETWORK)
fd = netopen (filename);
#else
internal_warning (_("/dev/(tcp|udp)/host/port not supported without networking"));
fd = open (filename, flags, mode);
#endif
break;
#endif /* NETWORK_REDIRECTIONS */
}
return fd;
}
/* Open FILENAME with FLAGS in noclobber mode, hopefully avoiding most
race conditions and avoiding the problem where the file is replaced
between the stat(2) and open(2). */
static int
noclobber_open (filename, flags, mode, ri)
char *filename;
int flags, mode;
enum r_instruction ri;
{
int r, fd;
struct stat finfo, finfo2;
/* If the file exists and is a regular file, return an error
immediately. */
r = stat (filename, &finfo);
if (r == 0 && (S_ISREG (finfo.st_mode)))
return (NOCLOBBER_REDIRECT);
/* If the file was not present (r != 0), make sure we open it
exclusively so that if it is created before we open it, our open
will fail. Make sure that we do not truncate an existing file.
Note that we don't turn on O_EXCL unless the stat failed -- if
the file was not a regular file, we leave O_EXCL off. */
flags &= ~O_TRUNC;
if (r != 0)
{
fd = open (filename, flags|O_EXCL, mode);
return ((fd < 0 && errno == EEXIST) ? NOCLOBBER_REDIRECT : fd);
}
fd = open (filename, flags, mode);
/* If the open failed, return the file descriptor right away. */
if (fd < 0)
return (errno == EEXIST ? NOCLOBBER_REDIRECT : fd);
/* OK, the open succeeded, but the file may have been changed from a
non-regular file to a regular file between the stat and the open.
We are assuming that the O_EXCL open handles the case where FILENAME
did not exist and is symlinked to an existing file between the stat
and open. */
/* If we can open it and fstat the file descriptor, and neither check
revealed that it was a regular file, and the file has not been replaced,
return the file descriptor. */
if ((fstat (fd, &finfo2) == 0) && (S_ISREG (finfo2.st_mode) == 0) &&
r == 0 && (S_ISREG (finfo.st_mode) == 0) &&
same_file (filename, filename, &finfo, &finfo2))
return fd;
/* The file has been replaced. badness. */
close (fd);
errno = EEXIST;
return (NOCLOBBER_REDIRECT);
}
static int
redir_open (filename, flags, mode, ri)
char *filename;
int flags, mode;
enum r_instruction ri;
{
int fd, r, e;
r = find_string_in_alist (filename, _redir_special_filenames, 1);
if (r >= 0)
return (redir_special_open (r, filename, flags, mode, ri));
/* If we are in noclobber mode, you are not allowed to overwrite
existing files. Check before opening. */
if (noclobber && CLOBBERING_REDIRECT (ri))
{
fd = noclobber_open (filename, flags, mode, ri);
if (fd == NOCLOBBER_REDIRECT)
return (NOCLOBBER_REDIRECT);
}
else
{
do
{
fd = open (filename, flags, mode);
e = errno;
if (fd < 0 && e == EINTR)
QUIT;
errno = e;
}
while (fd < 0 && errno == EINTR);
#if defined (AFS)
if ((fd < 0) && (errno == EACCES))
{
fd = open (filename, flags & ~O_CREAT, mode);
errno = EACCES; /* restore errno */
}
#endif /* AFS */
}
return fd;
}
static int
undoablefd (fd)
int fd;
{
int clexec;
clexec = fcntl (fd, F_GETFD, 0);
if (clexec == -1 || (fd >= SHELL_FD_BASE && clexec == 1))
return 0;
return 1;
}
/* Do the specific redirection requested. Returns errno or one of the
special redirection errors (*_REDIRECT) in case of error, 0 on success.
If flags & RX_ACTIVE is zero, then just do whatever is necessary to
produce the appropriate side effects. flags & RX_UNDOABLE, if non-zero,
says to remember how to undo each redirection. If flags & RX_CLEXEC is
non-zero, then we set all file descriptors > 2 that we open to be
close-on-exec. */
static int
do_redirection_internal (redirect, flags)
REDIRECT *redirect;
int flags;
{
WORD_DESC *redirectee;
int redir_fd, fd, redirector, r, oflags;
intmax_t lfd;
char *redirectee_word;
enum r_instruction ri;
REDIRECT *new_redirect;
REDIRECTEE sd;
redirectee = redirect->redirectee.filename;
redir_fd = redirect->redirectee.dest;
redirector = redirect->redirector.dest;
ri = redirect->instruction;
if (redirect->flags & RX_INTERNAL)
flags |= RX_INTERNAL;
if (TRANSLATE_REDIRECT (ri))
{
/* We have [N]>&WORD[-] or [N]<&WORD[-] (or {V}>&WORD[-] or {V}<&WORD-).
and WORD, then translate the redirection into a new one and
continue. */
redirectee_word = redirection_expand (redirectee);
/* XXX - what to do with [N]<&$w- where w is unset or null? ksh93
closes N. */
if (redirectee_word == 0)
return (AMBIGUOUS_REDIRECT);
else if (redirectee_word[0] == '-' && redirectee_word[1] == '\0')
{
sd = redirect->redirector;
rd.dest = 0;
new_redirect = make_redirection (sd, r_close_this, rd, 0);
}
else if (all_digits (redirectee_word))
{
sd = redirect->redirector;
if (legal_number (redirectee_word, &lfd) && (int)lfd == lfd)
rd.dest = lfd;
else
rd.dest = -1; /* XXX */
switch (ri)
{
case r_duplicating_input_word:
new_redirect = make_redirection (sd, r_duplicating_input, rd, 0);
break;
case r_duplicating_output_word:
new_redirect = make_redirection (sd, r_duplicating_output, rd, 0);
break;
case r_move_input_word:
new_redirect = make_redirection (sd, r_move_input, rd, 0);
break;
case r_move_output_word:
new_redirect = make_redirection (sd, r_move_output, rd, 0);
break;
}
}
else if (ri == r_duplicating_output_word && (redirect->rflags & REDIR_VARASSIGN) == 0 && redirector == 1)
{
sd = redirect->redirector;
rd.filename = make_bare_word (redirectee_word);
new_redirect = make_redirection (sd, r_err_and_out, rd, 0);
}
else
{
free (redirectee_word);
return (AMBIGUOUS_REDIRECT);
}
free (redirectee_word);
/* Set up the variables needed by the rest of the function from the
new redirection. */
if (new_redirect->instruction == r_err_and_out)
{
char *alloca_hack;
/* Copy the word without allocating any memory that must be
explicitly freed. */
redirectee = (WORD_DESC *)alloca (sizeof (WORD_DESC));
xbcopy ((char *)new_redirect->redirectee.filename,
(char *)redirectee, sizeof (WORD_DESC));
alloca_hack = (char *)
alloca (1 + strlen (new_redirect->redirectee.filename->word));
redirectee->word = alloca_hack;
strcpy (redirectee->word, new_redirect->redirectee.filename->word);
}
else
/* It's guaranteed to be an integer, and shouldn't be freed. */
redirectee = new_redirect->redirectee.filename;
redir_fd = new_redirect->redirectee.dest;
redirector = new_redirect->redirector.dest;
ri = new_redirect->instruction;
/* Overwrite the flags element of the old redirect with the new value. */
redirect->flags = new_redirect->flags;
dispose_redirects (new_redirect);
}
switch (ri)
{
case r_output_direction:
case r_appending_to:
case r_input_direction:
case r_inputa_direction:
case r_err_and_out: /* command &>filename */
case r_append_err_and_out: /* command &>> filename */
case r_input_output:
case r_output_force:
if (posixly_correct && interactive_shell == 0)
{
oflags = redirectee->flags;
redirectee->flags |= W_NOGLOB;
}
redirectee_word = redirection_expand (redirectee);
if (posixly_correct && interactive_shell == 0)
redirectee->flags = oflags;
if (redirectee_word == 0)
return (AMBIGUOUS_REDIRECT);
#if defined (RESTRICTED_SHELL)
if (restricted && (WRITE_REDIRECT (ri)))
{
free (redirectee_word);
return (RESTRICTED_REDIRECT);
}
#endif /* RESTRICTED_SHELL */
fd = redir_open (redirectee_word, redirect->flags, 0666, ri);
free (redirectee_word);
if (fd == NOCLOBBER_REDIRECT)
return (fd);
if (fd < 0)
return (errno);
if (flags & RX_ACTIVE)
{
if (redirect->rflags & REDIR_VARASSIGN)
{
redirector = fcntl (fd, F_DUPFD, SHELL_FD_BASE); /* XXX try this for now */
r = errno;
if (redirector < 0)
sys_error (_("redirection error: cannot duplicate fd"));
REDIRECTION_ERROR (redirector, r, fd);
}
if ((flags & RX_UNDOABLE) && (redirect->rflags & REDIR_VARASSIGN) == 0)
{
/* Only setup to undo it if the thing to undo is active. */
if ((fd != redirector) && (fcntl (redirector, F_GETFD, 0) != -1))
r = add_undo_redirect (redirector, ri, -1);
else
r = add_undo_close_redirect (redirector);
REDIRECTION_ERROR (r, errno, fd);
}
#if defined (BUFFERED_INPUT)
/* inhibit call to sync_buffered_stream() for async processes */
if (redirector != 0 || (subshell_environment & SUBSHELL_ASYNC) == 0)
check_bash_input (redirector);
#endif
/* Make sure there is no pending output before we change the state
of the underlying file descriptor, since the builtins use stdio
for output. */
if (redirector == 1 && fileno (stdout) == redirector)
{
fflush (stdout);
fpurge (stdout);
}
else if (redirector == 2 && fileno (stderr) == redirector)
{
fflush (stderr);
fpurge (stderr);
}
if (redirect->rflags & REDIR_VARASSIGN)
{
if ((r = redir_varassign (redirect, redirector)) < 0)
{
close (redirector);
close (fd);
return (r); /* XXX */
}
}
else if ((fd != redirector) && (dup2 (fd, redirector) < 0))
return (errno);
#if defined (BUFFERED_INPUT)
/* Do not change the buffered stream for an implicit redirection
of /dev/null to fd 0 for asynchronous commands without job
control (r_inputa_direction). */
if (ri == r_input_direction || ri == r_input_output)
duplicate_buffered_stream (fd, redirector);
#endif /* BUFFERED_INPUT */
/*
* If we're remembering, then this is the result of a while, for
* or until loop with a loop redirection, or a function/builtin
* executing in the parent shell with a redirection. In the
* function/builtin case, we want to set all file descriptors > 2
* to be close-on-exec to duplicate the effect of the old
* for i = 3 to NOFILE close(i) loop. In the case of the loops,
* both sh and ksh leave the file descriptors open across execs.
* The Posix standard mentions only the exec builtin.
*/
if ((flags & RX_CLEXEC) && (redirector > 2))
SET_CLOSE_ON_EXEC (redirector);
}
if (fd != redirector)
{
#if defined (BUFFERED_INPUT)
if (INPUT_REDIRECT (ri))
close_buffered_fd (fd);
else
#endif /* !BUFFERED_INPUT */
close (fd); /* Don't close what we just opened! */
}
/* If we are hacking both stdout and stderr, do the stderr
redirection here. XXX - handle {var} here? */
if (ri == r_err_and_out || ri == r_append_err_and_out)
{
if (flags & RX_ACTIVE)
{
if (flags & RX_UNDOABLE)
add_undo_redirect (2, ri, -1);
if (dup2 (1, 2) < 0)
return (errno);
}
}
break;
case r_reading_until:
case r_deblank_reading_until:
case r_reading_string:
/* REDIRECTEE is a pointer to a WORD_DESC containing the text of
the new input. Place it in a temporary file. */
if (redirectee)
{
fd = here_document_to_fd (redirectee, ri);
if (fd < 0)
{
heredoc_errno = errno;
return (HEREDOC_REDIRECT);
}
if (redirect->rflags & REDIR_VARASSIGN)
{
redirector = fcntl (fd, F_DUPFD, SHELL_FD_BASE); /* XXX try this for now */
r = errno;
if (redirector < 0)
sys_error (_("redirection error: cannot duplicate fd"));
REDIRECTION_ERROR (redirector, r, fd);
}
if (flags & RX_ACTIVE)
{
if ((flags & RX_UNDOABLE) && (redirect->rflags & REDIR_VARASSIGN) == 0)
{
/* Only setup to undo it if the thing to undo is active. */
if ((fd != redirector) && (fcntl (redirector, F_GETFD, 0) != -1))
r = add_undo_redirect (redirector, ri, -1);
else
r = add_undo_close_redirect (redirector);
REDIRECTION_ERROR (r, errno, fd);
}
#if defined (BUFFERED_INPUT)
check_bash_input (redirector);
#endif
if (redirect->rflags & REDIR_VARASSIGN)
{
if ((r = redir_varassign (redirect, redirector)) < 0)
{
close (redirector);
close (fd);
return (r); /* XXX */
}
}
else if (fd != redirector && dup2 (fd, redirector) < 0)
{
r = errno;
close (fd);
return (r);
}
#if defined (BUFFERED_INPUT)
duplicate_buffered_stream (fd, redirector);
#endif
if ((flags & RX_CLEXEC) && (redirector > 2))
SET_CLOSE_ON_EXEC (redirector);
}
if (fd != redirector)
#if defined (BUFFERED_INPUT)
close_buffered_fd (fd);
#else
close (fd);
#endif
}
break;
case r_duplicating_input:
case r_duplicating_output:
case r_move_input:
case r_move_output:
if ((flags & RX_ACTIVE) && (redirect->rflags & REDIR_VARASSIGN))
{
redirector = fcntl (redir_fd, F_DUPFD, SHELL_FD_BASE); /* XXX try this for now */
r = errno;
if (redirector < 0)
sys_error (_("redirection error: cannot duplicate fd"));
REDIRECTION_ERROR (redirector, r, -1);
}
if ((flags & RX_ACTIVE) && (redir_fd != redirector))
{
if ((flags & RX_UNDOABLE) && (redirect->rflags & REDIR_VARASSIGN) == 0)
{
/* Only setup to undo it if the thing to undo is active. */
if (fcntl (redirector, F_GETFD, 0) != -1)
r = add_undo_redirect (redirector, ri, redir_fd);
else
r = add_undo_close_redirect (redirector);
REDIRECTION_ERROR (r, errno, -1);
}
if ((flags & RX_UNDOABLE) && (ri == r_move_input || ri == r_move_output))
{
/* r_move_input and r_move_output add an additional close()
that needs to be undone */
if (fcntl (redirector, F_GETFD, 0) != -1)
{
r = add_undo_redirect (redir_fd, r_close_this, -1);
REDIRECTION_ERROR (r, errno, -1);
}
}
#if defined (BUFFERED_INPUT)
/* inhibit call to sync_buffered_stream() for async processes */
if (redirector != 0 || (subshell_environment & SUBSHELL_ASYNC) == 0)
check_bash_input (redirector);
#endif
if (redirect->rflags & REDIR_VARASSIGN)
{
if ((r = redir_varassign (redirect, redirector)) < 0)
{
close (redirector);
return (r); /* XXX */
}
}
/* This is correct. 2>&1 means dup2 (1, 2); */
else if (dup2 (redir_fd, redirector) < 0)
return (errno);
#if defined (BUFFERED_INPUT)
if (ri == r_duplicating_input || ri == r_move_input)
duplicate_buffered_stream (redir_fd, redirector);
#endif /* BUFFERED_INPUT */
/* First duplicate the close-on-exec state of redirectee. dup2
leaves the flag unset on the new descriptor, which means it
stays open. Only set the close-on-exec bit for file descriptors
greater than 2 in any case, since 0-2 should always be open
unless closed by something like `exec 2<&-'. It should always
be safe to set fds > 2 to close-on-exec if they're being used to
save file descriptors < 2, since we don't need to preserve the
state of the close-on-exec flag for those fds -- they should
always be open. */
/* if ((already_set || set_unconditionally) && (ok_to_set))
set_it () */
#if 0
if (((fcntl (redir_fd, F_GETFD, 0) == 1) || redir_fd < 2 || (flags & RX_CLEXEC)) &&
(redirector > 2))
#else
if (((fcntl (redir_fd, F_GETFD, 0) == 1) || (redir_fd < 2 && (flags & RX_INTERNAL)) || (flags & RX_CLEXEC)) &&
(redirector > 2))
#endif
SET_CLOSE_ON_EXEC (redirector);
/* When undoing saving of non-standard file descriptors (>=3) using
file descriptors >= SHELL_FD_BASE, we set the saving fd to be
close-on-exec and use a flag to decide how to set close-on-exec
when the fd is restored. */
if ((redirect->flags & RX_INTERNAL) && (redirect->flags & RX_SAVCLEXEC) && redirector >= 3 && (redir_fd >= SHELL_FD_BASE || (redirect->flags & RX_SAVEFD)))
SET_OPEN_ON_EXEC (redirector);
/* dup-and-close redirection */
if (ri == r_move_input || ri == r_move_output)
{
xtrace_fdchk (redir_fd);
close (redir_fd);
#if defined (COPROCESS_SUPPORT)
coproc_fdchk (redir_fd); /* XXX - loses coproc fds */
#endif
}
}
break;
case r_close_this:
if (flags & RX_ACTIVE)
{
if (redirect->rflags & REDIR_VARASSIGN)
{
redirector = redir_varvalue (redirect);
if (redirector < 0)
return AMBIGUOUS_REDIRECT;
}
r = 0;
/* XXX - only if REDIR_VARASSIGN not set? */
if ((flags & RX_UNDOABLE) && (fcntl (redirector, F_GETFD, 0) != -1))
{
r = add_undo_redirect (redirector, ri, -1);
REDIRECTION_ERROR (r, errno, redirector);
}
#if defined (COPROCESS_SUPPORT)
coproc_fdchk (redirector);
#endif
xtrace_fdchk (redirector);
#if defined (BUFFERED_INPUT)
/* inhibit call to sync_buffered_stream() for async processes */
if (redirector != 0 || (subshell_environment & SUBSHELL_ASYNC) == 0)
check_bash_input (redirector);
r = close_buffered_fd (redirector);
#else /* !BUFFERED_INPUT */
r = close (redirector);
#endif /* !BUFFERED_INPUT */
if (r < 0 && (flags & RX_INTERNAL) && (errno == EIO || errno == ENOSPC))
REDIRECTION_ERROR (r, errno, -1);
}
break;
case r_duplicating_input_word:
case r_duplicating_output_word:
break;
}
return (0);
}
/* Remember the file descriptor associated with the slot FD,
on REDIRECTION_UNDO_LIST. Note that the list will be reversed
before it is executed. Any redirections that need to be undone
even if REDIRECTION_UNDO_LIST is discarded by the exec builtin
are also saved on EXEC_REDIRECTION_UNDO_LIST. FDBASE says where to
start the duplicating. If it's less than SHELL_FD_BASE, we're ok,
and can use SHELL_FD_BASE (-1 == don't care). If it's >= SHELL_FD_BASE,
we have to make sure we don't use fdbase to save a file descriptor,
since we're going to use it later (e.g., make sure we don't save fd 0
to fd 10 if we have a redirection like 0<&10). If the value of fdbase
puts the process over its fd limit, causing fcntl to fail, we try
again with SHELL_FD_BASE. Return 0 on success, -1 on error. */
static int
add_undo_redirect (fd, ri, fdbase)
int fd;
enum r_instruction ri;
int fdbase;
{
int new_fd, clexec_flag, savefd_flag;
REDIRECT *new_redirect, *closer, *dummy_redirect;
REDIRECTEE sd;
savefd_flag = 0;
new_fd = fcntl (fd, F_DUPFD, (fdbase < SHELL_FD_BASE) ? SHELL_FD_BASE : fdbase+1);
if (new_fd < 0)
new_fd = fcntl (fd, F_DUPFD, SHELL_FD_BASE);
if (new_fd < 0)
{
new_fd = fcntl (fd, F_DUPFD, 0);
savefd_flag = 1;
}
if (new_fd < 0)
{
sys_error (_("redirection error: cannot duplicate fd"));
return (-1);
}
clexec_flag = fcntl (fd, F_GETFD, 0);
sd.dest = new_fd;
rd.dest = 0;
closer = make_redirection (sd, r_close_this, rd, 0);
closer->flags |= RX_INTERNAL;
dummy_redirect = copy_redirects (closer);
sd.dest = fd;
rd.dest = new_fd;
if (fd == 0)
new_redirect = make_redirection (sd, r_duplicating_input, rd, 0);
else
new_redirect = make_redirection (sd, r_duplicating_output, rd, 0);
new_redirect->flags |= RX_INTERNAL;
if (savefd_flag)
new_redirect->flags |= RX_SAVEFD;
if (clexec_flag == 0 && fd >= 3 && (new_fd >= SHELL_FD_BASE || savefd_flag))
new_redirect->flags |= RX_SAVCLEXEC;
new_redirect->next = closer;
closer->next = redirection_undo_list;
redirection_undo_list = new_redirect;
/* Save redirections that need to be undone even if the undo list
is thrown away by the `exec' builtin. */
add_exec_redirect (dummy_redirect);
/* experimental: if we're saving a redirection to undo for a file descriptor
above SHELL_FD_BASE, add a redirection to be undone if the exec builtin
causes redirections to be discarded. There needs to be a difference
between fds that are used to save other fds and then are the target of
user redirections and fds that are just the target of user redirections.
We use the close-on-exec flag to tell the difference; fds > SHELL_FD_BASE
that have the close-on-exec flag set are assumed to be fds used internally
to save others. */
if (fd >= SHELL_FD_BASE && ri != r_close_this && clexec_flag)
{
sd.dest = fd;
rd.dest = new_fd;
new_redirect = make_redirection (sd, r_duplicating_output, rd, 0);
new_redirect->flags |= RX_INTERNAL;
add_exec_redirect (new_redirect);
}
/* File descriptors used only for saving others should always be
marked close-on-exec. Unfortunately, we have to preserve the
close-on-exec state of the file descriptor we are saving, since
fcntl (F_DUPFD) sets the new file descriptor to remain open
across execs. If, however, the file descriptor whose state we
are saving is <= 2, we can just set the close-on-exec flag,
because file descriptors 0-2 should always be open-on-exec,
and the restore above in do_redirection() will take care of it. */
if (clexec_flag || fd < 3)
SET_CLOSE_ON_EXEC (new_fd);
else if (redirection_undo_list->flags & RX_SAVCLEXEC)
SET_CLOSE_ON_EXEC (new_fd);
return (0);
}
/* Set up to close FD when we are finished with the current command
and its redirections. Return 0 on success, -1 on error. */
static int
add_undo_close_redirect (fd)
int fd;
{
REDIRECT *closer;
REDIRECTEE sd;
sd.dest = fd;
rd.dest = 0;
closer = make_redirection (sd, r_close_this, rd, 0);
closer->flags |= RX_INTERNAL;
closer->next = redirection_undo_list;
redirection_undo_list = closer;
return 0;
}
static void
add_exec_redirect (dummy_redirect)
REDIRECT *dummy_redirect;
{
dummy_redirect->next = exec_redirection_undo_list;
exec_redirection_undo_list = dummy_redirect;
}
/* Return 1 if the redirection specified by RI and REDIRECTOR alters the
standard input. */
static int
stdin_redirection (ri, redirector)
enum r_instruction ri;
int redirector;
{
switch (ri)
{
case r_input_direction:
case r_inputa_direction:
case r_input_output:
case r_reading_until:
case r_deblank_reading_until:
case r_reading_string:
return (1);
case r_duplicating_input:
case r_duplicating_input_word:
case r_close_this:
return (redirector == 0);
case r_output_direction:
case r_appending_to:
case r_duplicating_output:
case r_err_and_out:
case r_append_err_and_out:
case r_output_force:
case r_duplicating_output_word:
return (0);
}
return (0);
}
/* Return non-zero if any of the redirections in REDIRS alter the standard
input. */
int
stdin_redirects (redirs)
REDIRECT *redirs;
{
REDIRECT *rp;
int n;
for (n = 0, rp = redirs; rp; rp = rp->next)
if ((rp->rflags & REDIR_VARASSIGN) == 0)
n += stdin_redirection (rp->instruction, rp->redirector.dest);
return n;
}
/* bind_var_to_int handles array references */
static int
redir_varassign (redir, fd)
REDIRECT *redir;
int fd;
{
WORD_DESC *w;
SHELL_VAR *v;
w = redir->redirector.filename;
v = bind_var_to_int (w->word, fd);
if (v == 0 || readonly_p (v) || noassign_p (v))
return BADVAR_REDIRECT;
stupidly_hack_special_variables (w->word);
return 0;
}
/* Handles {array[ind]} for redirection words */
static int
redir_varvalue (redir)
REDIRECT *redir;
{
SHELL_VAR *v;
char *val, *w;
intmax_t vmax;
int i;
#if defined (ARRAY_VARS)
char *sub;
int len, vr;
#endif
w = redir->redirector.filename->word; /* shorthand */
/* XXX - handle set -u here? */
#if defined (ARRAY_VARS)
if (vr = valid_array_reference (w))
v = array_variable_part (w, &sub, &len);
else
#endif
v = find_variable (w);
if (v == 0 || invisible_p (v))
return -1;
#if defined (ARRAY_VARS)
/* get_variable_value handles references to array variables without
subscripts */
if (vr && (array_p (v) || assoc_p (v)))
val = get_array_value (w, 0, (int *)NULL, (arrayind_t *)0);
else
#endif
val = get_variable_value (v);
if (val == 0 || *val == 0)
return -1;
if (legal_number (val, &vmax) < 0)
return -1;
i = vmax; /* integer truncation */
return i;
}
|