Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * path.c
4 : * portable path handling routines
5 : *
6 : * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
7 : * Portions Copyright (c) 1994, Regents of the University of California
8 : *
9 : *
10 : * IDENTIFICATION
11 : * src/port/path.c
12 : *
13 : *-------------------------------------------------------------------------
14 : */
15 :
16 : #ifndef FRONTEND
17 : #include "postgres.h"
18 : #else
19 : #include "postgres_fe.h"
20 : #endif
21 :
22 : #include <ctype.h>
23 : #include <sys/stat.h>
24 : #ifdef WIN32
25 : #ifdef _WIN32_IE
26 : #undef _WIN32_IE
27 : #endif
28 : #define _WIN32_IE 0x0500
29 : #ifdef near
30 : #undef near
31 : #endif
32 : #define near
33 : #include <shlobj.h>
34 : #else
35 : #include <pwd.h>
36 : #include <unistd.h>
37 : #endif
38 :
39 : #include "mb/pg_wchar.h"
40 : #include "pg_config_paths.h"
41 :
42 :
43 : #ifndef WIN32
44 : #define IS_PATH_VAR_SEP(ch) ((ch) == ':')
45 : #else
46 : #define IS_PATH_VAR_SEP(ch) ((ch) == ';')
47 : #endif
48 :
49 : #ifdef WIN32
50 : static void debackslash_path(char *path, int encoding);
51 : static int pg_sjis_mblen(const unsigned char *s);
52 : #endif
53 : static void make_relative_path(char *ret_path, const char *target_path,
54 : const char *bin_path, const char *my_exec_path);
55 : static char *trim_directory(char *path);
56 : static void trim_trailing_separator(char *path);
57 : static char *append_subdir_to_path(char *path, char *subdir);
58 :
59 :
60 : /*
61 : * skip_drive
62 : *
63 : * On Windows, a path may begin with "C:" or "//network/". Advance over
64 : * this and point to the effective start of the path.
65 : */
66 : #ifdef WIN32
67 :
68 : static char *
69 : skip_drive(const char *path)
70 : {
71 : if (IS_DIR_SEP(path[0]) && IS_DIR_SEP(path[1]))
72 : {
73 : path += 2;
74 : while (*path && !IS_DIR_SEP(*path))
75 : path++;
76 : }
77 : else if (isalpha((unsigned char) path[0]) && path[1] == ':')
78 : {
79 : path += 2;
80 : }
81 : return (char *) path;
82 : }
83 : #else
84 :
85 : #define skip_drive(path) (path)
86 : #endif
87 :
88 : /*
89 : * has_drive_prefix
90 : *
91 : * Return true if the given pathname has a drive prefix.
92 : */
93 : bool
94 0 : has_drive_prefix(const char *path)
95 : {
96 : #ifdef WIN32
97 : return skip_drive(path) != path;
98 : #else
99 0 : return false;
100 : #endif
101 : }
102 :
103 : /*
104 : * first_dir_separator
105 : *
106 : * Find the location of the first directory separator, return
107 : * NULL if not found.
108 : */
109 : char *
110 63149 : first_dir_separator(const char *filename)
111 : {
112 : const char *p;
113 :
114 448188 : for (p = skip_drive(filename); *p; p++)
115 401070 : if (IS_DIR_SEP(*p))
116 16031 : return unconstify(char *, p);
117 47118 : return NULL;
118 : }
119 :
120 : /*
121 : * first_path_var_separator
122 : *
123 : * Find the location of the first path separator (i.e. ':' on
124 : * Unix, ';' on Windows), return NULL if not found.
125 : */
126 : char *
127 27608 : first_path_var_separator(const char *pathlist)
128 : {
129 : const char *p;
130 :
131 : /* skip_drive is not needed */
132 498249 : for (p = pathlist; *p; p++)
133 476073 : if (IS_PATH_VAR_SEP(*p))
134 5432 : return unconstify(char *, p);
135 22176 : return NULL;
136 : }
137 :
138 : /*
139 : * last_dir_separator
140 : *
141 : * Find the location of the last directory separator, return
142 : * NULL if not found.
143 : */
144 : char *
145 191390 : last_dir_separator(const char *filename)
146 : {
147 : const char *p,
148 191390 : *ret = NULL;
149 :
150 4054902 : for (p = skip_drive(filename); *p; p++)
151 3863512 : if (IS_DIR_SEP(*p))
152 574320 : ret = p;
153 191390 : return unconstify(char *, ret);
154 : }
155 :
156 :
157 : #ifdef WIN32
158 :
159 : /*
160 : * Convert '\' to '/' within the given path, assuming the path
161 : * is in the specified encoding.
162 : */
163 : static void
164 : debackslash_path(char *path, int encoding)
165 : {
166 : char *p;
167 :
168 : /*
169 : * Of the supported encodings, only Shift-JIS has multibyte characters
170 : * that can include a byte equal to '\' (0x5C). So rather than implement
171 : * a fully encoding-aware conversion, we special-case SJIS. (Invoking the
172 : * general encoding-aware logic in wchar.c is impractical here for
173 : * assorted reasons.)
174 : */
175 : if (encoding == PG_SJIS)
176 : {
177 : for (p = path; *p; p += pg_sjis_mblen((const unsigned char *) p))
178 : {
179 : if (*p == '\\')
180 : *p = '/';
181 : }
182 : }
183 : else
184 : {
185 : for (p = path; *p; p++)
186 : {
187 : if (*p == '\\')
188 : *p = '/';
189 : }
190 : }
191 : }
192 :
193 : /*
194 : * SJIS character length
195 : *
196 : * This must match the behavior of
197 : * pg_encoding_mblen_bounded(PG_SJIS, s)
198 : * In particular, unlike the version of pg_sjis_mblen in src/common/wchar.c,
199 : * do not allow caller to accidentally step past end-of-string.
200 : */
201 : static int
202 : pg_sjis_mblen(const unsigned char *s)
203 : {
204 : int len;
205 :
206 : if (*s >= 0xa1 && *s <= 0xdf)
207 : len = 1; /* 1 byte kana? */
208 : else if (IS_HIGHBIT_SET(*s) && s[1] != '\0')
209 : len = 2; /* kanji? */
210 : else
211 : len = 1; /* should be ASCII */
212 : return len;
213 : }
214 :
215 : #endif /* WIN32 */
216 :
217 :
218 : /*
219 : * make_native_path - on WIN32, change '/' to '\' in the path
220 : *
221 : * This reverses the '\'-to-'/' transformation of debackslash_path.
222 : * We need not worry about encodings here, since '/' does not appear
223 : * as a byte of a multibyte character in any supported encoding.
224 : *
225 : * This is required because WIN32 COPY is an internal CMD.EXE
226 : * command and doesn't process forward slashes in the same way
227 : * as external commands. Quoting the first argument to COPY
228 : * does not convert forward to backward slashes, but COPY does
229 : * properly process quoted forward slashes in the second argument.
230 : *
231 : * COPY works with quoted forward slashes in the first argument
232 : * only if the current directory is the same as the directory
233 : * of the first argument.
234 : */
235 : void
236 958 : make_native_path(char *filename)
237 : {
238 : #ifdef WIN32
239 : char *p;
240 :
241 : for (p = filename; *p; p++)
242 : if (*p == '/')
243 : *p = '\\';
244 : #endif
245 958 : }
246 :
247 :
248 : /*
249 : * This function cleans up the paths for use with either cmd.exe or Msys
250 : * on Windows. We need them to use filenames without spaces, for which a
251 : * short filename is the safest equivalent, eg:
252 : * C:/Progra~1/
253 : *
254 : * Presently, this is only used on paths that we can assume are in a
255 : * server-safe encoding, so there's no need for an encoding-aware variant.
256 : */
257 : void
258 7215 : cleanup_path(char *path)
259 : {
260 : #ifdef WIN32
261 : /*
262 : * GetShortPathName() will fail if the path does not exist, or short names
263 : * are disabled on this file system. In both cases, we just return the
264 : * original path. This is particularly useful for --sysconfdir, which
265 : * might not exist.
266 : */
267 : GetShortPathName(path, path, MAXPGPATH - 1);
268 :
269 : /* Replace '\' with '/' */
270 : /* All server-safe encodings are alike here, so just use PG_SQL_ASCII */
271 : debackslash_path(path, PG_SQL_ASCII);
272 : #endif
273 7215 : }
274 :
275 :
276 : /*
277 : * join_path_components - join two path components, inserting a slash
278 : *
279 : * We omit the slash if either given component is empty.
280 : *
281 : * ret_path is the output area (must be of size MAXPGPATH)
282 : *
283 : * ret_path can be the same as head, but not the same as tail.
284 : */
285 : void
286 58926 : join_path_components(char *ret_path,
287 : const char *head, const char *tail)
288 : {
289 58926 : if (ret_path != head)
290 2129 : strlcpy(ret_path, head, MAXPGPATH);
291 :
292 : /*
293 : * We used to try to simplify some cases involving "." and "..", but now
294 : * we just leave that to be done by canonicalize_path() later.
295 : */
296 :
297 58926 : if (*tail)
298 : {
299 : /* only separate with slash if head wasn't empty */
300 58926 : snprintf(ret_path + strlen(ret_path), MAXPGPATH - strlen(ret_path),
301 : "%s%s",
302 58926 : (*(skip_drive(head)) != '\0') ? "/" : "",
303 : tail);
304 : }
305 58926 : }
306 :
307 :
308 : /* State-machine states for canonicalize_path */
309 : typedef enum
310 : {
311 : ABSOLUTE_PATH_INIT, /* Just past the leading '/' (and Windows
312 : * drive name if any) of an absolute path */
313 : ABSOLUTE_WITH_N_DEPTH, /* We collected 'pathdepth' directories in an
314 : * absolute path */
315 : RELATIVE_PATH_INIT, /* At start of a relative path */
316 : RELATIVE_WITH_N_DEPTH, /* We collected 'pathdepth' directories in a
317 : * relative path */
318 : RELATIVE_WITH_PARENT_REF, /* Relative path containing only double-dots */
319 : } canonicalize_state;
320 :
321 : /*
322 : * canonicalize_path()
323 : *
324 : * Clean up path by:
325 : * o make Win32 path use Unix slashes
326 : * o remove trailing quote on Win32
327 : * o remove trailing slash
328 : * o remove duplicate (adjacent) separators
329 : * o remove '.' (unless path reduces to only '.')
330 : * o process '..' ourselves, removing it if possible
331 : * Modifies path in-place.
332 : *
333 : * This comes in two variants: encoding-aware and not. The non-aware version
334 : * is only safe to use on strings that are in a server-safe encoding.
335 : */
336 : void
337 538384 : canonicalize_path(char *path)
338 : {
339 : /* All server-safe encodings are alike here, so just use PG_SQL_ASCII */
340 538384 : canonicalize_path_enc(path, PG_SQL_ASCII);
341 538384 : }
342 :
343 : void
344 538453 : canonicalize_path_enc(char *path, int encoding)
345 : {
346 : char *p,
347 : *to_p;
348 : char *spath;
349 : char *parsed;
350 : char *unparse;
351 538453 : bool was_sep = false;
352 : canonicalize_state state;
353 538453 : int pathdepth = 0; /* counts collected regular directory names */
354 :
355 : #ifdef WIN32
356 :
357 : /*
358 : * The Windows command processor will accept suitably quoted paths with
359 : * forward slashes, but barfs badly with mixed forward and back slashes.
360 : * Hence, start by converting all back slashes to forward slashes.
361 : */
362 : debackslash_path(path, encoding);
363 :
364 : /*
365 : * In Win32, if you do: prog.exe "a b" "\c\d\" the system will pass \c\d"
366 : * as argv[2], so trim off trailing quote.
367 : */
368 : p = path + strlen(path);
369 : if (p > path && *(p - 1) == '"')
370 : *(p - 1) = '/';
371 : #endif
372 :
373 : /*
374 : * Removing the trailing slash on a path means we never get ugly double
375 : * trailing slashes. Also, Win32 can't stat() a directory with a trailing
376 : * slash. Don't remove a leading slash, though.
377 : */
378 538453 : trim_trailing_separator(path);
379 :
380 : /*
381 : * Remove duplicate adjacent separators
382 : */
383 538453 : p = path;
384 : #ifdef WIN32
385 : /* Don't remove leading double-slash on Win32 */
386 : if (*p)
387 : p++;
388 : #endif
389 538453 : to_p = p;
390 14532291 : for (; *p; p++, to_p++)
391 : {
392 : /* Handle many adjacent slashes, like "/a///b" */
393 13993838 : while (*p == '/' && was_sep)
394 0 : p++;
395 13993838 : if (to_p != p)
396 0 : *to_p = *p;
397 13993838 : was_sep = (*p == '/');
398 : }
399 538453 : *to_p = '\0';
400 :
401 : /*
402 : * Remove any uses of "." and process ".." ourselves
403 : *
404 : * Note that "/../.." should reduce to just "/", while "../.." has to be
405 : * kept as-is. Also note that we want a Windows drive spec to be visible
406 : * to trim_directory(), but it's not part of the logic that's looking at
407 : * the name components; hence distinction between path and spath.
408 : *
409 : * This loop overwrites the path in-place. This is safe since we'll never
410 : * make the path longer. "unparse" points to where we are reading the
411 : * path, "parse" to where we are writing.
412 : */
413 538453 : spath = skip_drive(path);
414 538453 : if (*spath == '\0')
415 47 : return; /* empty path is returned as-is */
416 :
417 538406 : if (*spath == '/')
418 : {
419 144584 : state = ABSOLUTE_PATH_INIT;
420 : /* Skip the leading slash for absolute path */
421 144584 : parsed = unparse = (spath + 1);
422 : }
423 : else
424 : {
425 393822 : state = RELATIVE_PATH_INIT;
426 393822 : parsed = unparse = spath;
427 : }
428 :
429 3037346 : while (*unparse != '\0')
430 : {
431 : char *unparse_next;
432 : bool is_double_dot;
433 :
434 : /* Split off this dir name, and set unparse_next to the next one */
435 2498940 : unparse_next = unparse;
436 14387655 : while (*unparse_next && *unparse_next != '/')
437 11888715 : unparse_next++;
438 2498940 : if (*unparse_next != '\0')
439 1960539 : *unparse_next++ = '\0';
440 :
441 : /* Identify type of this dir name */
442 2498940 : if (strcmp(unparse, ".") == 0)
443 : {
444 : /* We can ignore "." components in all cases */
445 38801 : unparse = unparse_next;
446 38801 : continue;
447 : }
448 :
449 2460139 : if (strcmp(unparse, "..") == 0)
450 182 : is_double_dot = true;
451 : else
452 : {
453 : /* adjacent separators were eliminated above */
454 : Assert(*unparse != '\0');
455 2459957 : is_double_dot = false;
456 : }
457 :
458 2460139 : switch (state)
459 : {
460 144624 : case ABSOLUTE_PATH_INIT:
461 : /* We can ignore ".." immediately after / */
462 144624 : if (!is_double_dot)
463 : {
464 : /* Append first dir name (we already have leading slash) */
465 144594 : parsed = append_subdir_to_path(parsed, unparse);
466 144594 : state = ABSOLUTE_WITH_N_DEPTH;
467 144594 : pathdepth++;
468 : }
469 144624 : break;
470 1180241 : case ABSOLUTE_WITH_N_DEPTH:
471 1180241 : if (is_double_dot)
472 : {
473 : /* Remove last parsed dir */
474 : /* (trim_directory won't remove the leading slash) */
475 72 : *parsed = '\0';
476 72 : parsed = trim_directory(path);
477 72 : if (--pathdepth == 0)
478 25 : state = ABSOLUTE_PATH_INIT;
479 : }
480 : else
481 : {
482 : /* Append normal dir */
483 1180169 : *parsed++ = '/';
484 1180169 : parsed = append_subdir_to_path(parsed, unparse);
485 1180169 : pathdepth++;
486 : }
487 1180241 : break;
488 393780 : case RELATIVE_PATH_INIT:
489 393780 : if (is_double_dot)
490 : {
491 : /* Append irreducible double-dot (..) */
492 30 : parsed = append_subdir_to_path(parsed, unparse);
493 30 : state = RELATIVE_WITH_PARENT_REF;
494 : }
495 : else
496 : {
497 : /* Append normal dir */
498 393750 : parsed = append_subdir_to_path(parsed, unparse);
499 393750 : state = RELATIVE_WITH_N_DEPTH;
500 393750 : pathdepth++;
501 : }
502 393780 : break;
503 741454 : case RELATIVE_WITH_N_DEPTH:
504 741454 : if (is_double_dot)
505 : {
506 : /* Remove last parsed dir */
507 45 : *parsed = '\0';
508 45 : parsed = trim_directory(path);
509 45 : if (--pathdepth == 0)
510 : {
511 : /*
512 : * If the output path is now empty, we're back to the
513 : * INIT state. However, we could have processed a
514 : * path like "../dir/.." and now be down to "..", in
515 : * which case enter the correct state for that.
516 : */
517 35 : if (parsed == spath)
518 20 : state = RELATIVE_PATH_INIT;
519 : else
520 15 : state = RELATIVE_WITH_PARENT_REF;
521 : }
522 : }
523 : else
524 : {
525 : /* Append normal dir */
526 741409 : *parsed++ = '/';
527 741409 : parsed = append_subdir_to_path(parsed, unparse);
528 741409 : pathdepth++;
529 : }
530 741454 : break;
531 40 : case RELATIVE_WITH_PARENT_REF:
532 40 : if (is_double_dot)
533 : {
534 : /* Append next irreducible double-dot (..) */
535 5 : *parsed++ = '/';
536 5 : parsed = append_subdir_to_path(parsed, unparse);
537 : }
538 : else
539 : {
540 : /* Append normal dir */
541 35 : *parsed++ = '/';
542 35 : parsed = append_subdir_to_path(parsed, unparse);
543 :
544 : /*
545 : * We can now start counting normal dirs. But if later
546 : * double-dots make us remove this dir again, we'd better
547 : * revert to RELATIVE_WITH_PARENT_REF not INIT state.
548 : */
549 35 : state = RELATIVE_WITH_N_DEPTH;
550 35 : pathdepth = 1;
551 : }
552 40 : break;
553 : }
554 :
555 2460139 : unparse = unparse_next;
556 : }
557 :
558 : /*
559 : * If our output path is empty at this point, insert ".". We don't want
560 : * to do this any earlier because it'd result in an extra dot in corner
561 : * cases such as "../dir/..". Since we rejected the wholly-empty-path
562 : * case above, there is certainly room.
563 : */
564 538406 : if (parsed == spath)
565 62 : *parsed++ = '.';
566 :
567 : /* And finally, ensure the output path is nul-terminated. */
568 538406 : *parsed = '\0';
569 : }
570 :
571 : /*
572 : * Detect whether a path contains any parent-directory references ("..")
573 : *
574 : * The input *must* have been put through canonicalize_path previously.
575 : */
576 : bool
577 366510 : path_contains_parent_reference(const char *path)
578 : {
579 : /*
580 : * Once canonicalized, an absolute path cannot contain any ".." at all,
581 : * while a relative path could contain ".."(s) only at the start. So it
582 : * is sufficient to check the start of the path, after skipping any
583 : * Windows drive/network specifier.
584 : */
585 366510 : path = skip_drive(path); /* C: shouldn't affect our conclusion */
586 :
587 366510 : if (path[0] == '.' &&
588 25 : path[1] == '.' &&
589 0 : (path[2] == '\0' || path[2] == '/'))
590 0 : return true;
591 :
592 366510 : return false;
593 : }
594 :
595 : /*
596 : * Detect whether a path is only in or below the current working directory.
597 : *
598 : * The input *must* have been put through canonicalize_path previously.
599 : *
600 : * An absolute path that matches the current working directory should
601 : * return false (we only want relative to the cwd).
602 : */
603 : bool
604 366510 : path_is_relative_and_below_cwd(const char *path)
605 : {
606 366510 : if (is_absolute_path(path))
607 0 : return false;
608 : /* don't allow anything above the cwd */
609 366510 : else if (path_contains_parent_reference(path))
610 0 : return false;
611 : #ifdef WIN32
612 :
613 : /*
614 : * On Win32, a drive letter _not_ followed by a slash, e.g. 'E:abc', is
615 : * relative to the cwd on that drive, or the drive's root directory if
616 : * that drive has no cwd. Because the path itself cannot tell us which is
617 : * the case, we have to assume the worst, i.e. that it is not below the
618 : * cwd. We could use GetFullPathName() to find the full path but that
619 : * could change if the current directory for the drive changes underneath
620 : * us, so we just disallow it.
621 : */
622 : else if (isalpha((unsigned char) path[0]) && path[1] == ':' &&
623 : !IS_DIR_SEP(path[2]))
624 : return false;
625 : #endif
626 : else
627 366510 : return true;
628 : }
629 :
630 : /*
631 : * Detect whether a path is safe for use during archive extraction.
632 : *
633 : * This applies canonicalize_path(), then it checks that the path does
634 : * not contain any parent directory references.
635 : */
636 : bool
637 359339 : path_is_safe_for_extraction(const char *path)
638 : {
639 : char buf[MAXPGPATH];
640 :
641 359339 : strlcpy(buf, path, sizeof(buf));
642 359339 : canonicalize_path(buf);
643 :
644 359339 : return path_is_relative_and_below_cwd(buf);
645 : }
646 :
647 : /*
648 : * Detect whether path1 is a prefix of path2 (including equality).
649 : *
650 : * This is pretty trivial, but it seems better to export a function than
651 : * to export IS_DIR_SEP.
652 : */
653 : bool
654 83 : path_is_prefix_of_path(const char *path1, const char *path2)
655 : {
656 83 : int path1_len = strlen(path1);
657 :
658 83 : if (strncmp(path1, path2, path1_len) == 0 &&
659 0 : (IS_DIR_SEP(path2[path1_len]) || path2[path1_len] == '\0'))
660 0 : return true;
661 83 : return false;
662 : }
663 :
664 : /*
665 : * Extracts the actual name of the program as called -
666 : * stripped of .exe suffix if any
667 : */
668 : const char *
669 33976 : get_progname(const char *argv0)
670 : {
671 : const char *nodir_name;
672 : char *progname;
673 :
674 33976 : nodir_name = last_dir_separator(argv0);
675 33976 : if (nodir_name)
676 26389 : nodir_name++;
677 : else
678 7587 : nodir_name = skip_drive(argv0);
679 :
680 : /*
681 : * Make a copy in case argv[0] is modified by ps_status. Leaks memory, but
682 : * called only once.
683 : */
684 33976 : progname = strdup(nodir_name);
685 33976 : if (progname == NULL)
686 : {
687 0 : fprintf(stderr, "%s: out of memory\n", nodir_name);
688 0 : abort(); /* This could exit the postmaster */
689 : }
690 :
691 : #if defined(__CYGWIN__) || defined(WIN32)
692 : /* strip ".exe" suffix, regardless of case */
693 : if (strlen(progname) > sizeof(EXE) - 1 &&
694 : pg_strcasecmp(progname + strlen(progname) - (sizeof(EXE) - 1), EXE) == 0)
695 : progname[strlen(progname) - (sizeof(EXE) - 1)] = '\0';
696 : #endif
697 :
698 33976 : return progname;
699 : }
700 :
701 :
702 : /*
703 : * dir_strcmp: strcmp except any two DIR_SEP characters are considered equal,
704 : * and we honor filesystem case insensitivity if known
705 : */
706 : static int
707 51115 : dir_strcmp(const char *s1, const char *s2)
708 : {
709 204460 : while (*s1 && *s2)
710 : {
711 153345 : if (
712 : #ifndef WIN32
713 153345 : *s1 != *s2
714 : #else
715 : /* On windows, paths are case-insensitive */
716 : pg_tolower((unsigned char) *s1) != pg_tolower((unsigned char) *s2)
717 : #endif
718 0 : && !(IS_DIR_SEP(*s1) && IS_DIR_SEP(*s2)))
719 0 : return (int) *s1 - (int) *s2;
720 153345 : s1++, s2++;
721 : }
722 51115 : if (*s1)
723 0 : return 1; /* s1 longer */
724 51115 : if (*s2)
725 0 : return -1; /* s2 longer */
726 51115 : return 0;
727 : }
728 :
729 :
730 : /*
731 : * make_relative_path - make a path relative to the actual binary location
732 : *
733 : * This function exists to support relocation of installation trees.
734 : *
735 : * ret_path is the output area (must be of size MAXPGPATH)
736 : * target_path is the compiled-in path to the directory we want to find
737 : * bin_path is the compiled-in path to the directory of executables
738 : * my_exec_path is the actual location of my executable
739 : *
740 : * We determine the common prefix of target_path and bin_path, then compare
741 : * the remainder of bin_path to the last directory component(s) of
742 : * my_exec_path. If they match, build the result as the part of my_exec_path
743 : * preceding the match, joined to the remainder of target_path. If no match,
744 : * return target_path as-is.
745 : *
746 : * For example:
747 : * target_path = '/usr/local/share/postgresql'
748 : * bin_path = '/usr/local/bin'
749 : * my_exec_path = '/opt/pgsql/bin/postgres'
750 : * Given these inputs, the common prefix is '/usr/local/', the tail of
751 : * bin_path is 'bin' which does match the last directory component of
752 : * my_exec_path, so we would return '/opt/pgsql/share/postgresql'
753 : */
754 : static void
755 52277 : make_relative_path(char *ret_path, const char *target_path,
756 : const char *bin_path, const char *my_exec_path)
757 : {
758 : int prefix_len;
759 : int tail_start;
760 : int tail_len;
761 : int i;
762 :
763 : /*
764 : * Determine the common prefix --- note we require it to end on a
765 : * directory separator, consider eg '/usr/lib' and '/usr/libexec'.
766 : */
767 52277 : prefix_len = 0;
768 940986 : for (i = 0; target_path[i] && bin_path[i]; i++)
769 : {
770 940986 : if (IS_DIR_SEP(target_path[i]) && IS_DIR_SEP(bin_path[i]))
771 209108 : prefix_len = i + 1;
772 731878 : else if (target_path[i] != bin_path[i])
773 52277 : break;
774 : }
775 52277 : if (prefix_len == 0)
776 0 : goto no_match; /* no common prefix? */
777 52277 : tail_len = strlen(bin_path) - prefix_len;
778 :
779 : /*
780 : * Set up my_exec_path without the actual executable name, and
781 : * canonicalize to simplify comparison to bin_path.
782 : */
783 52277 : strlcpy(ret_path, my_exec_path, MAXPGPATH);
784 52277 : trim_directory(ret_path); /* remove my executable name */
785 52277 : canonicalize_path(ret_path);
786 :
787 : /*
788 : * Tail match?
789 : */
790 52277 : tail_start = (int) strlen(ret_path) - tail_len;
791 52277 : if (tail_start > 0 &&
792 103392 : IS_DIR_SEP(ret_path[tail_start - 1]) &&
793 51115 : dir_strcmp(ret_path + tail_start, bin_path + prefix_len) == 0)
794 : {
795 51115 : ret_path[tail_start] = '\0';
796 51115 : trim_trailing_separator(ret_path);
797 51115 : join_path_components(ret_path, ret_path, target_path + prefix_len);
798 51115 : canonicalize_path(ret_path);
799 51115 : return;
800 : }
801 :
802 1162 : no_match:
803 1162 : strlcpy(ret_path, target_path, MAXPGPATH);
804 1162 : canonicalize_path(ret_path);
805 : }
806 :
807 :
808 : /*
809 : * make_absolute_path
810 : *
811 : * If the given pathname isn't already absolute, make it so, interpreting
812 : * it relative to the current working directory.
813 : *
814 : * Also canonicalizes the path. The result is always a malloc'd copy.
815 : *
816 : * In backend, failure cases result in ereport(ERROR); in frontend,
817 : * we write a complaint on stderr and return NULL.
818 : *
819 : * Note: interpretation of relative-path arguments during postmaster startup
820 : * should happen before doing ChangeToDataDir(), else the user will probably
821 : * not like the results.
822 : */
823 : char *
824 3067 : make_absolute_path(const char *path)
825 : {
826 : char *new;
827 :
828 : /* Returning null for null input is convenient for some callers */
829 3067 : if (path == NULL)
830 0 : return NULL;
831 :
832 3067 : if (!is_absolute_path(path))
833 : {
834 : char *buf;
835 : size_t buflen;
836 :
837 420 : buflen = MAXPGPATH;
838 : for (;;)
839 : {
840 0 : buf = malloc(buflen);
841 420 : if (!buf)
842 : {
843 : #ifndef FRONTEND
844 0 : ereport(ERROR,
845 : (errcode(ERRCODE_OUT_OF_MEMORY),
846 : errmsg("out of memory")));
847 : #else
848 0 : fprintf(stderr, _("out of memory\n"));
849 0 : return NULL;
850 : #endif
851 : }
852 :
853 420 : if (getcwd(buf, buflen))
854 420 : break;
855 0 : else if (errno == ERANGE)
856 : {
857 0 : free(buf);
858 0 : buflen *= 2;
859 0 : continue;
860 : }
861 : else
862 : {
863 0 : int save_errno = errno;
864 :
865 0 : free(buf);
866 0 : errno = save_errno;
867 : #ifndef FRONTEND
868 0 : elog(ERROR, "could not get current working directory: %m");
869 : #else
870 0 : fprintf(stderr, _("could not get current working directory: %m\n"));
871 0 : return NULL;
872 : #endif
873 : }
874 : }
875 :
876 420 : new = malloc(strlen(buf) + strlen(path) + 2);
877 420 : if (!new)
878 : {
879 0 : free(buf);
880 : #ifndef FRONTEND
881 0 : ereport(ERROR,
882 : (errcode(ERRCODE_OUT_OF_MEMORY),
883 : errmsg("out of memory")));
884 : #else
885 0 : fprintf(stderr, _("out of memory\n"));
886 0 : return NULL;
887 : #endif
888 : }
889 420 : sprintf(new, "%s/%s", buf, path);
890 420 : free(buf);
891 : }
892 : else
893 : {
894 2647 : new = strdup(path);
895 2647 : if (!new)
896 : {
897 : #ifndef FRONTEND
898 0 : ereport(ERROR,
899 : (errcode(ERRCODE_OUT_OF_MEMORY),
900 : errmsg("out of memory")));
901 : #else
902 0 : fprintf(stderr, _("out of memory\n"));
903 0 : return NULL;
904 : #endif
905 : }
906 : }
907 :
908 : /* Make sure punctuation is canonical, too */
909 3067 : canonicalize_path(new);
910 :
911 3067 : return new;
912 : }
913 :
914 :
915 : /*
916 : * get_share_path
917 : */
918 : void
919 11169 : get_share_path(const char *my_exec_path, char *ret_path)
920 : {
921 11169 : make_relative_path(ret_path, PGSHAREDIR, PGBINDIR, my_exec_path);
922 11169 : }
923 :
924 : /*
925 : * get_etc_path
926 : */
927 : void
928 13781 : get_etc_path(const char *my_exec_path, char *ret_path)
929 : {
930 13781 : make_relative_path(ret_path, SYSCONFDIR, PGBINDIR, my_exec_path);
931 13781 : }
932 :
933 : /*
934 : * get_include_path
935 : */
936 : void
937 626 : get_include_path(const char *my_exec_path, char *ret_path)
938 : {
939 626 : make_relative_path(ret_path, INCLUDEDIR, PGBINDIR, my_exec_path);
940 626 : }
941 :
942 : /*
943 : * get_pkginclude_path
944 : */
945 : void
946 566 : get_pkginclude_path(const char *my_exec_path, char *ret_path)
947 : {
948 566 : make_relative_path(ret_path, PKGINCLUDEDIR, PGBINDIR, my_exec_path);
949 566 : }
950 :
951 : /*
952 : * get_includeserver_path
953 : */
954 : void
955 555 : get_includeserver_path(const char *my_exec_path, char *ret_path)
956 : {
957 555 : make_relative_path(ret_path, INCLUDEDIRSERVER, PGBINDIR, my_exec_path);
958 555 : }
959 :
960 : /*
961 : * get_lib_path
962 : */
963 : void
964 555 : get_lib_path(const char *my_exec_path, char *ret_path)
965 : {
966 555 : make_relative_path(ret_path, LIBDIR, PGBINDIR, my_exec_path);
967 555 : }
968 :
969 : /*
970 : * get_pkglib_path
971 : */
972 : void
973 2402 : get_pkglib_path(const char *my_exec_path, char *ret_path)
974 : {
975 2402 : make_relative_path(ret_path, PKGLIBDIR, PGBINDIR, my_exec_path);
976 2402 : }
977 :
978 : /*
979 : * get_locale_path
980 : */
981 : void
982 20958 : get_locale_path(const char *my_exec_path, char *ret_path)
983 : {
984 20958 : make_relative_path(ret_path, LOCALEDIR, PGBINDIR, my_exec_path);
985 20958 : }
986 :
987 : /*
988 : * get_doc_path
989 : */
990 : void
991 555 : get_doc_path(const char *my_exec_path, char *ret_path)
992 : {
993 555 : make_relative_path(ret_path, DOCDIR, PGBINDIR, my_exec_path);
994 555 : }
995 :
996 : /*
997 : * get_html_path
998 : */
999 : void
1000 555 : get_html_path(const char *my_exec_path, char *ret_path)
1001 : {
1002 555 : make_relative_path(ret_path, HTMLDIR, PGBINDIR, my_exec_path);
1003 555 : }
1004 :
1005 : /*
1006 : * get_man_path
1007 : */
1008 : void
1009 555 : get_man_path(const char *my_exec_path, char *ret_path)
1010 : {
1011 555 : make_relative_path(ret_path, MANDIR, PGBINDIR, my_exec_path);
1012 555 : }
1013 :
1014 :
1015 : /*
1016 : * get_home_path
1017 : *
1018 : * On Unix, this actually returns the user's home directory. On Windows
1019 : * it returns the PostgreSQL-specific application data folder.
1020 : */
1021 : bool
1022 0 : get_home_path(char *ret_path)
1023 : {
1024 : #ifndef WIN32
1025 : /*
1026 : * We first consult $HOME. If that's unset, try to get the info from
1027 : * <pwd.h>.
1028 : */
1029 : const char *home;
1030 :
1031 0 : home = getenv("HOME");
1032 0 : if (home && home[0])
1033 : {
1034 0 : strlcpy(ret_path, home, MAXPGPATH);
1035 0 : return true;
1036 : }
1037 : else
1038 : {
1039 : struct passwd pwbuf;
1040 : struct passwd *pw;
1041 : char buf[1024];
1042 : int rc;
1043 :
1044 0 : rc = getpwuid_r(geteuid(), &pwbuf, buf, sizeof buf, &pw);
1045 0 : if (rc != 0 || !pw)
1046 0 : return false;
1047 0 : strlcpy(ret_path, pw->pw_dir, MAXPGPATH);
1048 0 : return true;
1049 : }
1050 : #else
1051 : char *tmppath;
1052 :
1053 : /*
1054 : * Note: We use getenv() here because the more modern SHGetFolderPath()
1055 : * would force the backend to link with shell32.lib, which eats valuable
1056 : * desktop heap. XXX This function is used only in psql, which already
1057 : * brings in shell32 via libpq. Moving this function to its own file
1058 : * would keep it out of the backend, freeing it from this concern.
1059 : */
1060 : tmppath = getenv("APPDATA");
1061 : if (!tmppath)
1062 : return false;
1063 : snprintf(ret_path, MAXPGPATH, "%s/postgresql", tmppath);
1064 : return true;
1065 : #endif
1066 : }
1067 :
1068 :
1069 : /*
1070 : * get_parent_directory
1071 : *
1072 : * Modify the given string in-place to name the parent directory of the
1073 : * named file.
1074 : *
1075 : * If the input is just a file name with no directory part, the result is
1076 : * an empty string, not ".". This is appropriate when the next step is
1077 : * join_path_components(), but might need special handling otherwise.
1078 : *
1079 : * Caution: this will not produce desirable results if the string ends
1080 : * with "..". For most callers this is not a problem since the string
1081 : * is already known to name a regular file. If in doubt, apply
1082 : * canonicalize_path() first.
1083 : */
1084 : void
1085 8711 : get_parent_directory(char *path)
1086 : {
1087 8711 : trim_directory(path);
1088 8711 : }
1089 :
1090 :
1091 : /*
1092 : * trim_directory
1093 : *
1094 : * Trim trailing directory from path, that is, remove any trailing slashes,
1095 : * the last pathname component, and the slash just ahead of it --- but never
1096 : * remove a leading slash.
1097 : *
1098 : * For the convenience of canonicalize_path, the path's new end location
1099 : * is returned.
1100 : */
1101 : static char *
1102 61105 : trim_directory(char *path)
1103 : {
1104 : char *p;
1105 :
1106 61105 : path = skip_drive(path);
1107 :
1108 61105 : if (path[0] == '\0')
1109 0 : return path;
1110 :
1111 : /* back up over trailing slash(es) */
1112 61105 : for (p = path + strlen(path) - 1; IS_DIR_SEP(*p) && p > path; p--)
1113 : ;
1114 : /* back up over directory name */
1115 594092 : for (; !IS_DIR_SEP(*p) && p > path; p--)
1116 : ;
1117 : /* if multiple slashes before directory name, remove 'em all */
1118 61105 : for (; p > path && IS_DIR_SEP(*(p - 1)); p--)
1119 : ;
1120 : /* don't erase a leading slash */
1121 61105 : if (p == path && IS_DIR_SEP(*p))
1122 25 : p++;
1123 61105 : *p = '\0';
1124 61105 : return p;
1125 : }
1126 :
1127 :
1128 : /*
1129 : * trim_trailing_separator
1130 : *
1131 : * trim off trailing slashes, but not a leading slash
1132 : */
1133 : static void
1134 589568 : trim_trailing_separator(char *path)
1135 : {
1136 : char *p;
1137 :
1138 589568 : path = skip_drive(path);
1139 589568 : p = path + strlen(path);
1140 589568 : if (p > path)
1141 650455 : for (p--; p > path && IS_DIR_SEP(*p); p--)
1142 60934 : *p = '\0';
1143 589568 : }
1144 :
1145 : /*
1146 : * append_subdir_to_path
1147 : *
1148 : * Append the currently-considered subdirectory name to the output
1149 : * path in canonicalize_path. Return the new end location of the
1150 : * output path.
1151 : *
1152 : * Since canonicalize_path updates the path in-place, we must use
1153 : * memmove not memcpy, and we don't yet terminate the path with '\0'.
1154 : */
1155 : static char *
1156 2459992 : append_subdir_to_path(char *path, char *subdir)
1157 : {
1158 2459992 : size_t len = strlen(subdir);
1159 :
1160 : /* No need to copy data if path and subdir are the same. */
1161 2459992 : if (path != subdir)
1162 89778 : memmove(path, subdir, len);
1163 :
1164 2459992 : return path + len;
1165 : }
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