1 /* OPENBSD ORIGINAL: lib/libc/stdlib/realpath.c */
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37 #if !defined(HAVE_REALPATH) || defined(BROKEN_REALPATH)
39 #if defined(LIBC_SCCS) && !defined(lint)
40 static char *rcsid = "$OpenBSD: realpath.c,v 1.10 2003/08/01 21:04:59 millert Exp $";
41 #endif /* LIBC_SCCS and not lint */
43 #include <sys/param.h>
60 * char *realpath(const char *path, char resolved_path[MAXPATHLEN]);
62 * Find the real name of path, by removing all ".", ".." and symlink
63 * components. Returns (resolved) on success, or (NULL) on failure,
64 * in which case the path which caused trouble is left in (resolved).
67 realpath(const char *path, char *resolved)
70 int fd, n, needslash, serrno = 0;
71 char *p, *q, wbuf[MAXPATHLEN], start[MAXPATHLEN];
74 /* Save the starting point. */
75 getcwd(start,MAXPATHLEN);
76 if ((fd = open(".", O_RDONLY)) < 0) {
77 (void)strlcpy(resolved, ".", MAXPATHLEN);
82 /* Convert "." -> "" to optimize away a needless lstat() and chdir() */
83 if (path[0] == '.' && path[1] == '\0')
87 * Find the dirname and basename from the path to be resolved.
88 * Change directory to the dirname component.
89 * lstat the basename part.
90 * if it is a symlink, read in the value and loop.
91 * if it is a directory, then change to that directory.
92 * get the current directory name and append the basename.
94 strlcpy(resolved, path, MAXPATHLEN);
96 q = strrchr(resolved, '/');
104 } while (q > resolved && *q == '/');
113 /* Deal with the last component. */
114 if (*p != '\0' && lstat(p, &sb) == 0) {
115 if (S_ISLNK(sb.st_mode)) {
116 if (++symlinks > MAXSYMLINKS) {
120 n = readlink(p, resolved, MAXPATHLEN-1);
126 if (S_ISDIR(sb.st_mode)) {
134 * Save the last component name and get the full pathname of
135 * the current directory.
137 (void)strlcpy(wbuf, p, sizeof wbuf);
138 if (getcwd(resolved, MAXPATHLEN) == 0)
142 * Join the two strings together, ensuring that the right thing
143 * happens if the last component is empty, or the dirname is root.
145 if (resolved[0] == '/' && resolved[1] == '\0')
151 if (strlen(resolved) + strlen(wbuf) + needslash >= MAXPATHLEN) {
152 serrno = ENAMETOOLONG;
156 strlcat(resolved, "/", MAXPATHLEN);
157 strlcat(resolved, wbuf, MAXPATHLEN);
160 /* Go back to where we came from. */
161 if (chdir(start) < 0) {
168 err2: errno = serrno;
171 #endif /* !defined(HAVE_REALPATH) || defined(BROKEN_REALPATH) */