+\f
+/*
+ * readlink(2) stuff
+ */
+
+/* a wrapped version of readlink(2):
+ * -- If path isn't a symlink, or is a broken symlink, return 0.
+ * -- If path is a symlink, return a newly allocated string holding
+ * the thing it's linked to. */
+char *
+wrapped_readlink(char *path)
+{
+ int bufsiz = strlen(path) + 16;
+ while (1) {
+ char *result = malloc(bufsiz);
+ int n_read = readlink(path, result, n_read);
+ if (n_read < 0) {
+ free(result);
+ return 0;
+ } else if (n_read < bufsiz) {
+ result[n_read] = 0;
+ return result;
+ } else {
+ free(result);
+ bufsiz *= 2;
+ }
+ }
+}
+\f
+/*
+ * stat(2) stuff
+ */
+
+/* As of 0.6.12, the FFI can't handle 64-bit values. For now, we use
+ * these munged-to-32-bits values for might-be-64-bit slots of
+ * stat_wrapper as a workaround, so that at least we can still work
+ * when values are small.
+ *
+ * FIXME: But of course we should fix the FFI so that we can use the
+ * actual 64-bit values instead. */
+typedef long ffi_dev_t; /* since Linux dev_t can be 64 bits */
+typedef u32 ffi_off_t; /* since OpenBSD 2.8 st_size is 64 bits */
+
+/* a representation of stat(2) results which doesn't depend on CPU or OS */
+struct stat_wrapper {
+ /* KLUDGE: The verbose wrapped_st_ prefixes are to protect us from
+ * the C preprocessor as wielded by the fiends of OpenBSD, who do
+ * things like
+ * #define st_atime st_atimespec.tv_sec
+ * I remember when I was young and innocent, I read about how the
+ * C preprocessor isn't to be used to globally munge random
+ * lowercase symbols like this, because things like this could
+ * happen, and I nodded sagely. But now I know better.:-| This is
+ * another entry for Dan Barlow's ongoing episodic rant about C
+ * header files, I guess.. -- WHN 2001-05-10 */
+ ffi_dev_t wrapped_st_dev; /* device */
+ ino_t wrapped_st_ino; /* inode */
+ mode_t wrapped_st_mode; /* protection */
+ nlink_t wrapped_st_nlink; /* number of hard links */
+ uid_t wrapped_st_uid; /* user ID of owner */
+ gid_t wrapped_st_gid; /* group ID of owner */
+ ffi_dev_t wrapped_st_rdev; /* device type (if inode device) */
+ ffi_off_t wrapped_st_size; /* total size, in bytes */
+ unsigned long wrapped_st_blksize; /* blocksize for filesystem I/O */
+ unsigned long wrapped_st_blocks; /* number of blocks allocated */
+ time_t wrapped_st_atime; /* time_t of last access */
+ time_t wrapped_st_mtime; /* time_t of last modification */
+ time_t wrapped_st_ctime; /* time_t of last change */
+};
+
+static void
+copy_to_stat_wrapper(struct stat_wrapper *to, struct stat *from)
+{
+#define FROB(stem) to->wrapped_st_##stem = from->st_##stem
+ FROB(dev);
+ FROB(ino);
+ FROB(mode);
+ FROB(nlink);
+ FROB(uid);
+ FROB(gid);
+ FROB(rdev);
+ FROB(size);
+ FROB(blksize);
+ FROB(blocks);
+ FROB(atime);
+ FROB(mtime);
+ FROB(ctime);
+#undef FROB
+}
+
+int
+stat_wrapper(const char *file_name, struct stat_wrapper *buf)
+{
+ struct stat real_buf;
+ int ret;
+ if ((ret = stat(file_name,&real_buf)) >= 0)
+ copy_to_stat_wrapper(buf, &real_buf);
+ return ret;
+}
+
+int
+lstat_wrapper(const char *file_name, struct stat_wrapper *buf)
+{
+ struct stat real_buf;
+ int ret;
+ if ((ret = lstat(file_name,&real_buf)) >= 0)
+ copy_to_stat_wrapper(buf, &real_buf);
+ return ret;
+}
+
+int
+fstat_wrapper(int filedes, struct stat_wrapper *buf)
+{
+ struct stat real_buf;
+ int ret;
+ if ((ret = fstat(filedes,&real_buf)) >= 0)
+ copy_to_stat_wrapper(buf, &real_buf);
+ return ret;
+}