version 1.1, 1993/03/21 09:45:37 |
version 1.40, 2005/08/13 21:16:58 |
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/* $NetBSD$ */ |
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/* |
/* |
* Copyright (c) 1989, 1991 The Regents of the University of California. |
* Copyright (c) 1989, 1991, 1993, 1995 |
* All rights reserved. |
* The Regents of the University of California. All rights reserved. |
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* |
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* This code is derived from software contributed to Berkeley by |
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* Jan-Simon Pendry. |
* |
* |
* Redistribution and use in source and binary forms, with or without |
* Redistribution and use in source and binary forms, with or without |
* modification, are permitted provided that the following conditions |
* modification, are permitted provided that the following conditions |
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* 2. Redistributions in binary form must reproduce the above copyright |
* 2. Redistributions in binary form must reproduce the above copyright |
* notice, this list of conditions and the following disclaimer in the |
* notice, this list of conditions and the following disclaimer in the |
* documentation and/or other materials provided with the distribution. |
* documentation and/or other materials provided with the distribution. |
* 3. All advertising materials mentioning features or use of this software |
* 3. Neither the name of the University nor the names of its contributors |
* must display the following acknowledgement: |
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* This product includes software developed by the University of |
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* California, Berkeley and its contributors. |
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* 4. Neither the name of the University nor the names of its contributors |
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* may be used to endorse or promote products derived from this software |
* may be used to endorse or promote products derived from this software |
* without specific prior written permission. |
* without specific prior written permission. |
* |
* |
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* SUCH DAMAGE. |
* SUCH DAMAGE. |
*/ |
*/ |
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#include <sys/cdefs.h> |
#if defined(LIBC_SCCS) && !defined(lint) |
#if defined(LIBC_SCCS) && !defined(lint) |
static char sccsid[] = "@(#)getcwd.c 5.11 (Berkeley) 2/24/91"; |
#if 0 |
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static char sccsid[] = "@(#)getcwd.c 8.5 (Berkeley) 2/7/95"; |
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#else |
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__RCSID("$NetBSD$"); |
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#endif |
#endif /* LIBC_SCCS and not lint */ |
#endif /* LIBC_SCCS and not lint */ |
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#include "namespace.h" |
#include <sys/param.h> |
#include <sys/param.h> |
#include <sys/stat.h> |
#include <sys/stat.h> |
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#include <assert.h> |
#include <errno.h> |
#include <errno.h> |
#include <dirent.h> |
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#include <stdio.h> |
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#include <stdlib.h> |
#include <stdlib.h> |
#include <string.h> |
#include <string.h> |
#include <unistd.h> |
#include <unistd.h> |
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#define ISDOT(dp) \ |
#include "extern.h" |
(dp->d_name[0] == '.' && (dp->d_name[1] == '\0' || \ |
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dp->d_name[1] == '.' && dp->d_name[2] == '\0')) |
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#ifdef __weak_alias |
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__weak_alias(getcwd,_getcwd) |
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__weak_alias(realpath,_realpath) |
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#endif |
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/* |
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* char *realpath(const char *path, char resolved[MAXPATHLEN]); |
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* |
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* Find the real name of path, by removing all ".", ".." and symlink |
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* components. Returns (resolved) on success, or (NULL) on failure, |
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* in which case the path which caused trouble is left in (resolved). |
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*/ |
char * |
char * |
getcwd(pt, size) |
realpath(const char *path, char *resolved) |
char *pt; |
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size_t size; |
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{ |
{ |
register struct dirent *dp; |
struct stat sb; |
register DIR *dir; |
int idx = 0, n, nlnk = 0; |
register dev_t dev; |
const char *q; |
register ino_t ino; |
char *p, wbuf[2][MAXPATHLEN]; |
register int first; |
size_t len; |
register char *bpt, *bup; |
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struct stat s; |
_DIAGASSERT(path != NULL); |
dev_t root_dev; |
_DIAGASSERT(resolved != NULL); |
ino_t root_ino; |
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size_t ptsize, upsize; |
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int save_errno; |
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char *ept, *eup, *up; |
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/* |
/* |
* If no buffer specified by the user, allocate one as necessary. |
* Build real path one by one with paying an attention to ., |
* If a buffer is specified, the size has to be non-zero. The path |
* .. and symbolic link. |
* is built from the end of the buffer backwards. |
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*/ |
*/ |
if (pt) { |
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ptsize = 0; |
/* |
if (!size) { |
* `p' is where we'll put a new component with prepending |
errno = EINVAL; |
* a delimiter. |
return((char *)NULL); |
*/ |
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p = resolved; |
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if (*path == 0) { |
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*p = 0; |
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errno = ENOENT; |
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return (NULL); |
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} |
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/* If relative path, start from current working directory. */ |
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if (*path != '/') { |
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if (getcwd(resolved, MAXPATHLEN) == NULL) { |
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p[0] = '.'; |
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p[1] = 0; |
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return (NULL); |
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} |
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len = strlen(resolved); |
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if (len > 1) |
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p += len; |
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} |
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loop: |
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/* Skip any slash. */ |
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while (*path == '/') |
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path++; |
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if (*path == 0) { |
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if (p == resolved) |
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*p++ = '/'; |
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*p = 0; |
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return (resolved); |
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} |
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/* Find the end of this component. */ |
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q = path; |
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do |
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q++; |
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while (*q != '/' && *q != 0); |
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/* Test . or .. */ |
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if (path[0] == '.') { |
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if (q - path == 1) { |
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path = q; |
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goto loop; |
} |
} |
ept = pt + size; |
if (path[1] == '.' && q - path == 2) { |
} else { |
/* Trim the last component. */ |
if (!(pt = (char *)malloc(ptsize = 1024 - 4))) |
if (p != resolved) |
return((char *)NULL); |
while (*--p != '/') |
ept = pt + ptsize; |
; |
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path = q; |
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goto loop; |
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} |
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} |
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/* Append this component. */ |
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if (p - resolved + 1 + q - path + 1 > MAXPATHLEN) { |
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errno = ENAMETOOLONG; |
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if (p == resolved) |
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*p++ = '/'; |
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*p = 0; |
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return (NULL); |
} |
} |
bpt = ept - 1; |
p[0] = '/'; |
*bpt = '\0'; |
memcpy(&p[1], path, |
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/* LINTED We know q > path. */ |
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q - path); |
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p[1 + q - path] = 0; |
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/* |
/* |
* Allocate bytes (1024 - malloc space) for the string of "../"'s. |
* If this component is a symlink, toss it and prepend link |
* Should always be enough (it's 340 levels). If it's not, allocate |
* target to unresolved path. |
* as necessary. Special * case the first stat, it's ".", not "..". |
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*/ |
*/ |
if (!(up = (char *)malloc(upsize = 1024 - 4))) |
if (lstat(resolved, &sb) == -1) { |
goto err; |
return (NULL); |
eup = up + MAXPATHLEN; |
} |
bup = up; |
if (S_ISLNK(sb.st_mode)) { |
up[0] = '.'; |
if (nlnk++ >= MAXSYMLINKS) { |
up[1] = '\0'; |
errno = ELOOP; |
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return (NULL); |
/* Save root values, so know when to stop. */ |
} |
if (stat("/", &s)) |
n = readlink(resolved, wbuf[idx], sizeof(wbuf[0]) - 1); |
goto err; |
if (n < 0) |
root_dev = s.st_dev; |
return (NULL); |
root_ino = s.st_ino; |
if (n == 0) { |
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errno = ENOENT; |
errno = 0; /* XXX readdir has no error return. */ |
return (NULL); |
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} |
for (first = 1;; first = 0) { |
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/* Stat the current level. */ |
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if (lstat(up, &s)) |
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goto err; |
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/* Save current node values. */ |
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ino = s.st_ino; |
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dev = s.st_dev; |
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/* Check for reaching root. */ |
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if (root_dev == dev && root_ino == ino) { |
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*--bpt = '/'; |
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/* |
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* It's unclear that it's a requirement to copy the |
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* path to the beginning of the buffer, but it's always |
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* been that way and stuff would probably break. |
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*/ |
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(void)bcopy(bpt, pt, ept - bpt); |
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free(up); |
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return(pt); |
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} |
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/* |
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* Build pointer to the parent directory, allocating memory |
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* as necessary. Max length is 3 for "../", the largest |
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* possible component name, plus a trailing NULL. |
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*/ |
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if (bup + 3 + MAXNAMLEN + 1 >= eup) { |
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if (!(up = (char *)realloc(up, upsize *= 2))) |
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goto err; |
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eup = up + upsize; |
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} |
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*bup++ = '.'; |
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*bup++ = '.'; |
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*bup = '\0'; |
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/* Open and stat parent directory. */ |
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if (!(dir = opendir(up)) || fstat(dirfd(dir), &s)) |
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goto err; |
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/* Add trailing slash for next directory. */ |
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*bup++ = '/'; |
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/* |
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* If it's a mount point, have to stat each element because |
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* the inode number in the directory is for the entry in the |
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* parent directory, not the inode number of the mounted file. |
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*/ |
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save_errno = 0; |
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if (s.st_dev == dev) { |
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for (;;) { |
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if (!(dp = readdir(dir))) |
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goto notfound; |
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if (dp->d_fileno == ino) |
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break; |
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} |
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} else |
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for (;;) { |
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if (!(dp = readdir(dir))) |
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goto notfound; |
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if (ISDOT(dp)) |
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continue; |
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bcopy(dp->d_name, bup, dp->d_namlen + 1); |
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/* Save the first error for later. */ |
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if (lstat(up, &s)) { |
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if (!save_errno) |
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save_errno = errno; |
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errno = 0; |
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continue; |
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} |
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if (s.st_dev == dev && s.st_ino == ino) |
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break; |
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} |
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/* |
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* Check for length of the current name, preceding slash, |
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* leading slash. |
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*/ |
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if (bpt - pt <= dp->d_namlen + (first ? 1 : 2)) { |
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size_t len, off; |
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if (!ptsize) { |
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errno = ERANGE; |
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goto err; |
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} |
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off = bpt - pt; |
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len = ept - bpt; |
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if (!(pt = (char *)realloc(pt, ptsize *= 2))) |
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goto err; |
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bpt = pt + off; |
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ept = pt + ptsize; |
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(void)bcopy(bpt, ept - len, len); |
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bpt = ept - len; |
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} |
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if (!first) |
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*--bpt = '/'; |
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bpt -= dp->d_namlen; |
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bcopy(dp->d_name, bpt, dp->d_namlen); |
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(void)closedir(dir); |
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/* Truncate any file name. */ |
/* Append unresolved path to link target and switch to it. */ |
*bup = '\0'; |
if (n + (len = strlen(q)) + 1 > sizeof(wbuf[0])) { |
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errno = ENAMETOOLONG; |
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return (NULL); |
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} |
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memcpy(&wbuf[idx][n], q, len + 1); |
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path = wbuf[idx]; |
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idx ^= 1; |
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/* If absolute symlink, start from root. */ |
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if (*path == '/') |
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p = resolved; |
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goto loop; |
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} |
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if (*q == '/' && !S_ISDIR(sb.st_mode)) { |
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errno = ENOTDIR; |
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return (NULL); |
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} |
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/* Advance both resolved and unresolved path. */ |
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p += 1 + q - path; |
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path = q; |
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goto loop; |
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} |
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char * |
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getcwd(char *pt, size_t size) |
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{ |
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char *npt; |
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/* |
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* If a buffer is specified, the size has to be non-zero. |
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*/ |
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if (pt != NULL) { |
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if (size == 0) { |
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/* __getcwd(pt, 0) results ERANGE. */ |
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errno = EINVAL; |
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return (NULL); |
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} |
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if (__getcwd(pt, size) >= 0) |
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return (pt); |
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return (NULL); |
} |
} |
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notfound: |
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/* |
/* |
* If readdir set errno, use it, not any saved error; otherwise, |
* If no buffer specified by the user, allocate one as necessary. |
* didn't find the current directory in its parent directory, set |
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* errno to ENOENT. |
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*/ |
*/ |
if (!errno) |
size = 1024 >> 1; |
errno = save_errno ? save_errno : ENOENT; |
do { |
/* FALLTHROUGH */ |
if ((npt = realloc(pt, size <<= 1)) == NULL) |
err: |
break; |
if (ptsize) |
pt = npt; |
free(pt); |
if (__getcwd(pt, size) >= 0) |
free(up); |
return (pt); |
return((char *)NULL); |
} while (size <= MAXPATHLEN * 4 && errno == ERANGE); |
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free(pt); |
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return (NULL); |
} |
} |