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 1.11 2004/11/30 15:12:59 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;
71 char *p, *q, wbuf[MAXPATHLEN];
74 /* Save the starting point. */
76 char start[MAXPATHLEN];
77 /* this is potentially racy but without fchdir we have no option */
78 if (getcwd(start, sizeof(start)) == NULL) {
84 if ((fd = open(".", O_RDONLY)) < 0) {
90 /* Convert "." -> "" to optimize away a needless lstat() and chdir() */
91 if (path[0] == '.' && path[1] == '\0')
95 * Find the dirname and basename from the path to be resolved.
96 * Change directory to the dirname component.
97 * lstat the basename part.
98 * if it is a symlink, read in the value and loop.
99 * if it is a directory, then change to that directory.
100 * get the current directory name and append the basename.
102 if (strlcpy(resolved, path, MAXPATHLEN) >= MAXPATHLEN) {
103 serrno = ENAMETOOLONG;
107 q = strrchr(resolved, '/');
115 } while (q > resolved && *q == '/');
124 /* Deal with the last component. */
125 if (*p != '\0' && lstat(p, &sb) == 0) {
126 if (S_ISLNK(sb.st_mode)) {
127 if (++symlinks > MAXSYMLINKS) {
131 if ((n = readlink(p, resolved, MAXPATHLEN-1)) < 0)
136 if (S_ISDIR(sb.st_mode)) {
144 * Save the last component name and get the full pathname of
145 * the current directory.
147 if (strlcpy(wbuf, p, sizeof(wbuf)) >= sizeof(wbuf)) {
148 errno = ENAMETOOLONG;
151 if (getcwd(resolved, MAXPATHLEN) == NULL)
155 * Join the two strings together, ensuring that the right thing
156 * happens if the last component is empty, or the dirname is root.
158 if (resolved[0] == '/' && resolved[1] == '\0')
164 if (strlen(resolved) + strlen(wbuf) + needslash >= MAXPATHLEN) {
165 errno = ENAMETOOLONG;
169 if (strlcat(resolved, "/", MAXPATHLEN) >= MAXPATHLEN) {
170 errno = ENAMETOOLONG;
174 if (strlcat(resolved, wbuf, MAXPATHLEN) >= MAXPATHLEN) {
175 errno = ENAMETOOLONG;
180 /* Go back to where we came from. */
182 if (fchdir(fd) < 0) {
184 if (chdir(start) < 0) {
190 /* It's okay if the close fails, what's an fd more or less? */
194 err1: serrno = errno;
200 err2: (void)close(fd);
204 #endif /* !defined(HAVE_REALPATH) || defined(BROKEN_REALPATH) */