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-rw-r--r--lib/dirfd.c109
1 files changed, 109 insertions, 0 deletions
diff --git a/lib/dirfd.c b/lib/dirfd.c
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index 0000000..75b2163
--- /dev/null
+++ b/lib/dirfd.c
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+/* dirfd.c -- return the file descriptor associated with an open DIR*
+
+ Copyright (C) 2001, 2006, 2008-2023 Free Software Foundation, Inc.
+
+ This file is free software: you can redistribute it and/or modify
+ it under the terms of the GNU Lesser General Public License as
+ published by the Free Software Foundation; either version 2.1 of the
+ License, or (at your option) any later version.
+
+ This file is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with this program. If not, see <https://www.gnu.org/licenses/>. */
+
+/* Written by Jim Meyering. */
+
+#include <config.h>
+
+#include <dirent.h>
+#include <errno.h>
+
+#if GNULIB_defined_DIR
+# include "dirent-private.h"
+#endif
+
+#ifdef __KLIBC__
+# include <stdlib.h>
+# include <io.h>
+
+static struct dirp_fd_list
+{
+ DIR *dirp;
+ int fd;
+ struct dirp_fd_list *next;
+} *dirp_fd_start = NULL;
+
+/* Register fd associated with dirp to dirp_fd_list. */
+int
+_gl_register_dirp_fd (int fd, DIR *dirp)
+{
+ struct dirp_fd_list *new_dirp_fd = malloc (sizeof *new_dirp_fd);
+ if (!new_dirp_fd)
+ return -1;
+
+ new_dirp_fd->dirp = dirp;
+ new_dirp_fd->fd = fd;
+ new_dirp_fd->next = dirp_fd_start;
+
+ dirp_fd_start = new_dirp_fd;
+
+ return 0;
+}
+
+/* Unregister fd from dirp_fd_list with closing it */
+void
+_gl_unregister_dirp_fd (int fd)
+{
+ struct dirp_fd_list *dirp_fd;
+ struct dirp_fd_list *dirp_fd_prev;
+
+ for (dirp_fd_prev = NULL, dirp_fd = dirp_fd_start; dirp_fd;
+ dirp_fd_prev = dirp_fd, dirp_fd = dirp_fd->next)
+ {
+ if (dirp_fd->fd == fd)
+ {
+ if (dirp_fd_prev)
+ dirp_fd_prev->next = dirp_fd->next;
+ else /* dirp_fd == dirp_fd_start */
+ dirp_fd_start = dirp_fd_start->next;
+
+ close (fd);
+ free (dirp_fd);
+ break;
+ }
+ }
+}
+#endif
+
+int
+dirfd (DIR *dir_p)
+{
+#if GNULIB_defined_DIR
+ int fd = dir_p->fd_to_close;
+ if (fd == -1)
+ errno = EINVAL;
+ return fd;
+#else
+ int fd = DIR_TO_FD (dir_p);
+ if (fd == -1)
+# ifndef __KLIBC__
+ errno = ENOTSUP;
+# else
+ {
+ struct dirp_fd_list *dirp_fd;
+
+ for (dirp_fd = dirp_fd_start; dirp_fd; dirp_fd = dirp_fd->next)
+ if (dirp_fd->dirp == dir_p)
+ return dirp_fd->fd;
+
+ errno = EINVAL;
+ }
+# endif
+
+ return fd;
+#endif
+}