1 /* $OpenBSD: getcwd.c,v 1.14 2005/08/08 08:05:34 espie Exp */
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31 /* OPENBSD ORIGINAL: lib/libc/gen/getcwd.c */
35 #if !defined(HAVE_GETCWD)
47 (dp->d_name[0] == '.' && (dp->d_name[1] == '\0' || \
48 (dp->d_name[1] == '.' && dp->d_name[2] == '\0')))
51 getcwd(char *pt, size_t size)
62 size_t ptsize, upsize;
67 * If no buffer specified by the user, allocate one as necessary.
68 * If a buffer is specified, the size has to be non-zero. The path
69 * is built from the end of the buffer backwards.
76 } else if (size == 1) {
82 if ((pt = malloc(ptsize = MAXPATHLEN)) == NULL)
90 * Allocate bytes for the string of "../"'s.
91 * Should always be enough (it's 340 levels). If it's not, allocate
92 * as necessary. Special * case the first stat, it's ".", not "..".
94 if ((up = malloc(upsize = MAXPATHLEN)) == NULL)
101 /* Save root values, so know when to stop. */
107 errno = 0; /* XXX readdir has no error return. */
109 for (first = 1;; first = 0) {
110 /* Stat the current level. */
114 /* Save current node values. */
118 /* Check for reaching root. */
119 if (root_dev == dev && root_ino == ino) {
122 * It's unclear that it's a requirement to copy the
123 * path to the beginning of the buffer, but it's always
124 * been that way and stuff would probably break.
126 memmove(pt, bpt, ept - bpt);
132 * Build pointer to the parent directory, allocating memory
133 * as necessary. Max length is 3 for "../", the largest
134 * possible component name, plus a trailing NUL.
136 if (bup + 3 + MAXNAMLEN + 1 >= eup) {
139 if ((nup = realloc(up, upsize *= 2)) == NULL)
141 bup = nup + (bup - up);
149 /* Open and stat parent directory. */
150 if (!(dir = opendir(up)) || fstat(dirfd(dir), &s))
153 /* Add trailing slash for next directory. */
157 * If it's a mount point, have to stat each element because
158 * the inode number in the directory is for the entry in the
159 * parent directory, not the inode number of the mounted file.
162 if (s.st_dev == dev) {
164 if (!(dp = readdir(dir)))
166 if (dp->d_fileno == ino)
171 if (!(dp = readdir(dir)))
175 memcpy(bup, dp->d_name, dp->d_namlen + 1);
177 /* Save the first error for later. */
184 if (s.st_dev == dev && s.st_ino == ino)
189 * Check for length of the current name, preceding slash,
192 if (bpt - pt < dp->d_namlen + (first ? 1 : 2)) {
201 if ((npt = realloc(pt, ptsize *= 2)) == NULL)
203 bpt = npt + (bpt - pt);
206 memmove(ept - len, bpt, len);
212 memcpy(bpt, dp->d_name, dp->d_namlen);
215 /* Truncate any file name. */
221 * If readdir set errno, use it, not any saved error; otherwise,
222 * didn't find the current directory in its parent directory, set
226 errno = save_errno ? save_errno : ENOENT;
242 #endif /* !defined(HAVE_GETCWD) */