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5 * This code is derived from software contributed to Berkeley by
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32 #if !defined(HAVE_REALPATH) || defined(BROKEN_REALPATH)
34 #if defined(LIBC_SCCS) && !defined(lint)
35 static char *rcsid = "$OpenBSD: realpath..c,v 1.4 1998/05/18 09:55:19 deraadt Exp $";
36 #endif /* LIBC_SCCS and not lint */
38 #include <sys/param.h>
48 * S_ISLNK compatibility
51 #define S_ISLNK(m) ((m & 0170000) == 0120000)
62 * char *realpath(const char *path, char resolved_path[MAXPATHLEN]);
64 * Find the real name of path, by removing all ".", ".." and symlink
65 * components. Returns (resolved) on success, or (NULL) on failure,
66 * in which case the path which caused trouble is left in (resolved).
69 realpath(const char *path, char *resolved)
72 int fd, n, rootd, serrno = 0;
73 char *p, *q, wbuf[MAXPATHLEN], start[MAXPATHLEN];
76 /* Save the starting point. */
77 getcwd(start,MAXPATHLEN);
78 if ((fd = open(".", O_RDONLY)) < 0) {
79 (void)strcpy(resolved, ".");
85 * Find the dirname and basename from the path to be resolved.
86 * Change directory to the dirname component.
87 * lstat the basename part.
88 * if it is a symlink, read in the value and loop.
89 * if it is a directory, then change to that directory.
90 * get the current directory name and append the basename.
92 (void)strncpy(resolved, path, MAXPATHLEN - 1);
93 resolved[MAXPATHLEN - 1] = '\0';
95 q = strrchr(resolved, '/');
103 } while (q > resolved && *q == '/');
112 /* Deal with the last component. */
113 if (lstat(p, &sb) == 0) {
114 if (S_ISLNK(sb.st_mode)) {
115 if (++symlinks > MAXSYMLINKS) {
119 n = readlink(p, resolved, MAXPATHLEN-1);
125 if (S_ISDIR(sb.st_mode)) {
133 * Save the last component name and get the full pathname of
134 * the current directory.
136 (void)strcpy(wbuf, p);
137 if (getcwd(resolved, MAXPATHLEN) == 0)
141 * Join the two strings together, ensuring that the right thing
142 * happens if the last component is empty, or the dirname is root.
144 if (resolved[0] == '/' && resolved[1] == '\0')
150 if (strlen(resolved) + strlen(wbuf) + rootd + 1 > MAXPATHLEN) {
151 serrno = ENAMETOOLONG;
155 (void)strcat(resolved, "/");
156 (void)strcat(resolved, wbuf);
159 /* Go back to where we came from. */
160 if (chdir(start) < 0) {
167 err2: errno = serrno;
170 #endif /* !defined(HAVE_REALPATH) || defined(BROKEN_REALPATH) */