-/* Creates a new file named FN with the given PERMISSIONS bits,
- and returns a stream for it or a null pointer on failure.
- MODE should be "w" or "wb". */
-FILE *
-create_stream (const char *fn, const char *mode, mode_t permissions)
-{
- int fd;
- FILE *stream;
-
- fd = open (fn, O_WRONLY | O_CREAT | O_TRUNC, permissions);
- if (fd < 0)
- return NULL;
-
- stream = fdopen (fd, mode);
- if (stream == NULL)
- {
- int save_errno = errno;
- close (fd);
- errno = save_errno;
- }
-
- return stream;
-}
-
-/* A file's identity:
-
- - For a file that exists, this is its device and inode.
-
- - For a file that does not exist, but which has a directory
- name that exists, this is the device and inode of the
- directory, plus the file's base name.
-
- - For a file that does not exist and has a nonexistent
- directory, this is the file name.
-
- Windows doesn't have inode numbers, so we just use the name
- there. */
-struct file_identity
-{
- dev_t device; /* Device number. */
- ino_t inode; /* Inode number. */
- char *name; /* File name, where needed, otherwise NULL. */
-};
-
-/* Returns a pointer to a dynamically allocated structure whose
- value can be used to tell whether two files are actually the
- same file. Returns a null pointer if no information about the
- file is available, perhaps because it does not exist. The
- caller is responsible for freeing the structure with
- fn_free_identity() when finished. */
-struct file_identity *
-fn_get_identity (const char *file_name)
-{
- struct file_identity *identity = xmalloc (sizeof *identity);
-
-#if !(defined _WIN32 || defined __WIN32__)
- struct stat s;
- if (lstat (file_name, &s) == 0)
- {
- identity->device = s.st_dev;
- identity->inode = s.st_ino;
- identity->name = NULL;
- }
- else
- {
- char *dir = dir_name (file_name);
- if (last_component (file_name) != NULL && stat (dir, &s) == 0)
- {
- identity->device = s.st_dev;
- identity->inode = s.st_ino;
- identity->name = base_name (file_name);
- }
- else
- {
- identity->device = 0;
- identity->inode = 0;
- identity->name = xstrdup (file_name);
- }
- free (dir);
- }
-#else /* Windows */
- char cname[PATH_MAX];
- int ok = GetFullPathName (file_name, sizeof cname, cname, NULL);
- identity->device = 0;
- identity->inode = 0;
- identity->name = xstrdup (ok ? cname : file_name);
- str_lowercase (identity->name);
-#endif /* Windows */
-
- return identity;
-}
-
-/* Frees IDENTITY obtained from fn_get_identity(). */
-void
-fn_free_identity (struct file_identity *identity)
-{
- if (identity != NULL)
- {
- free (identity->name);
- free (identity);
- }
-}
-
-/* Compares A and B, returning a strcmp()-type result. */
-int
-fn_compare_file_identities (const struct file_identity *a,
- const struct file_identity *b)
-{
- if (a->device != b->device)
- return a->device < b->device ? -1 : 1;
- else if (a->inode != b->inode)
- return a->inode < b->inode ? -1 : 1;
- else if (a->name != NULL)
- return b->name != NULL ? strcmp (a->name, b->name) : 1;
- else
- return b->name != NULL ? -1 : 0;
-}
-
-/* Returns a hash value for IDENTITY. */
-unsigned int
-fn_hash_identity (const struct file_identity *identity)
-{
- unsigned int hash = hash_int (identity->device, identity->inode);
- if (identity->name != NULL)
- hash = hash_string (identity->name, hash);
- return hash;
-}