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Diffstat (limited to '')
-rw-r--r-- | lib/dirfd.c | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/lib/dirfd.c b/lib/dirfd.c new file mode 100644 index 0000000..75b2163 --- /dev/null +++ b/lib/dirfd.c @@ -0,0 +1,109 @@ +/* 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 +} |