+{
+ char *pwd;
+ size_t pwdlen;
+ dev_t dev;
+ ino_t ino;
+ struct stat s;
+
+ /* Check $PWD -- if it's right, it's fast. */
+ if ((pwd = getenv("PWD")) != NULL && pwd[0] == '/' && !stat(pwd, &s)) {
+ dev = s.st_dev;
+ ino = s.st_ino;
+ if (!stat(".", &s) && dev == s.st_dev && ino == s.st_ino) {
+ pwdlen = strlen(pwd);
+ if (size != 0) {
+ if (pwdlen + 1 > size) {
+ errno = ERANGE;
+ return (NULL);
+ }
+ } else if ((pt = malloc(pwdlen + 1)) == NULL)
+ return (NULL);
+ memmove(pt, pwd, pwdlen);
+ pt[pwdlen] = '\0';
+ return (pt);
+ }
+ }
+
+ return (getcwd_physical(pt, size));
+}
+
+/*
+ * char *realpath(const char *path, char resolved_path[MAXPATHLEN]);
+ *
+ * Find the real name of path, by removing all ".", ".." and symlink
+ * components. Returns (resolved) on success, or (NULL) on failure,
+ * in which case the path which caused trouble is left in (resolved).
+ */
+char *
+realpath(path, resolved)
+ const char *path;
+ char *resolved;
+{
+ struct stat sb;
+ int fd, n, rootd, serrno;
+ char *p, *q, wbuf[MAXPATHLEN];
+
+ /* Save the starting point. */
+ if ((fd = open(".", O_RDONLY)) < 0) {
+ (void)strcpy(resolved, ".");
+ return (NULL);
+ }
+
+ /*
+ * Find the dirname and basename from the path to be resolved.
+ * Change directory to the dirname component.
+ * lstat the basename part.
+ * if it is a symlink, read in the value and loop.
+ * if it is a directory, then change to that directory.
+ * get the current directory name and append the basename.
+ */
+ (void)strncpy(resolved, path, MAXPATHLEN - 1);
+ resolved[MAXPATHLEN - 1] = '\0';
+loop:
+ q = strrchr(resolved, '/');
+ if (q != NULL) {
+ p = q + 1;
+ if (q == resolved)
+ q = "/";
+ else {
+ do {
+ --q;
+ } while (q > resolved && *q == '/');
+ q[1] = '\0';
+ q = resolved;
+ }
+ if (chdir(q) < 0)
+ goto err1;
+ } else
+ p = resolved;
+
+ /* Deal with the last component. */
+ if (lstat(p, &sb) == 0) {
+ if (S_ISLNK(sb.st_mode)) {
+ n = readlink(p, resolved, MAXPATHLEN);
+ if (n < 0)
+ goto err1;
+ resolved[n] = '\0';
+ goto loop;
+ }
+ if (S_ISDIR(sb.st_mode)) {
+ if (chdir(p) < 0)
+ goto err1;
+ p = "";
+ }
+ }
+
+ /*
+ * Save the last component name and get the full pathname of
+ * the current directory.
+ */
+ (void)strcpy(wbuf, p);
+
+ /*
+ * Call the inernal internal version of getcwd which
+ * does a physical search rather than using the $PWD short-cut
+ */
+ if (getcwd_physical(resolved, MAXPATHLEN) == 0)
+ goto err1;
+
+ /*
+ * Join the two strings together, ensuring that the right thing
+ * happens if the last component is empty, or the dirname is root.
+ */
+ if (resolved[0] == '/' && resolved[1] == '\0')
+ rootd = 1;
+ else
+ rootd = 0;
+
+ if (*wbuf) {
+ if (strlen(resolved) + strlen(wbuf) + rootd + 1 > MAXPATHLEN) {
+ errno = ENAMETOOLONG;
+ goto err1;
+ }
+ if (rootd == 0)
+ (void)strcat(resolved, "/");
+ (void)strcat(resolved, wbuf);
+ }
+
+ /* Go back to where we came from. */
+ if (fchdir(fd) < 0) {
+ serrno = errno;
+ goto err2;
+ }
+
+ /* It's okay if the close fails, what's an fd more or less? */
+ (void)close(fd);
+ return (resolved);
+
+err1: serrno = errno;
+ (void)fchdir(fd);
+err2: (void)close(fd);
+ errno = serrno;
+ return (NULL);
+}
+
+static char *
+getcwd_physical(pt, size)
+ char *pt;
+ size_t size;
projects / unix-history / blobdiff