diff options
Diffstat (limited to 'sysdeps/posix/readdir_r.c')
-rw-r--r-- | sysdeps/posix/readdir_r.c | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/sysdeps/posix/readdir_r.c b/sysdeps/posix/readdir_r.c new file mode 100644 index 0000000000..bfa2c0b8f5 --- /dev/null +++ b/sysdeps/posix/readdir_r.c @@ -0,0 +1,137 @@ +/* Copyright (C) 1991,92,93,94,95,96,97,98,99,2000,02,10 + Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library 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. + + The GNU C Library 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 the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <errno.h> +#include <limits.h> +#include <stddef.h> +#include <string.h> +#include <dirent.h> +#include <unistd.h> +#include <sys/types.h> +#include <assert.h> + +#include <dirstream.h> + +#ifndef __READDIR_R +# define __READDIR_R __readdir_r +# define __GETDENTS __getdents +# define DIRENT_TYPE struct dirent +# define __READDIR_R_ALIAS +#endif + +/* Read a directory entry from DIRP. */ +int +__READDIR_R (DIR *dirp, DIRENT_TYPE *entry, DIRENT_TYPE **result) +{ + DIRENT_TYPE *dp; + size_t reclen; + const int saved_errno = errno; + + __libc_lock_lock (dirp->lock); + + do + { + if (dirp->offset >= dirp->size) + { + /* We've emptied out our buffer. Refill it. */ + + size_t maxread; + ssize_t bytes; + +#ifndef _DIRENT_HAVE_D_RECLEN + /* Fixed-size struct; must read one at a time (see below). */ + maxread = sizeof *dp; +#else + maxread = dirp->allocation; +#endif + + bytes = __GETDENTS (dirp->fd, dirp->data, maxread); + if (bytes <= 0) + { + /* On some systems getdents fails with ENOENT when the + open directory has been rmdir'd already. POSIX.1 + requires that we treat this condition like normal EOF. */ + if (bytes < 0 && errno == ENOENT) + { + bytes = 0; + __set_errno (saved_errno); + } + + dp = NULL; + /* Reclen != 0 signals that an error occurred. */ + reclen = bytes != 0; + break; + } + dirp->size = (size_t) bytes; + + /* Reset the offset into the buffer. */ + dirp->offset = 0; + } + + dp = (DIRENT_TYPE *) &dirp->data[dirp->offset]; + +#ifdef _DIRENT_HAVE_D_RECLEN + reclen = dp->d_reclen; +#else + /* The only version of `struct dirent*' that lacks `d_reclen' + is fixed-size. */ + assert (sizeof dp->d_name > 1); + reclen = sizeof *dp; + /* The name is not terminated if it is the largest possible size. + Clobber the following byte to ensure proper null termination. We + read just one entry at a time above so we know that byte will not + be used later. */ + dp->d_name[sizeof dp->d_name] = '\0'; +#endif + + dirp->offset += reclen; + +#ifdef _DIRENT_HAVE_D_OFF + dirp->filepos = dp->d_off; +#else + dirp->filepos += reclen; +#endif + + /* Skip deleted files. */ + } + while (dp->d_ino == 0); + + if (dp != NULL) + { +#ifdef GETDENTS_64BIT_ALIGNED + /* The d_reclen value might include padding which is not part of + the DIRENT_TYPE data structure. */ + reclen = MIN (reclen, + offsetof (DIRENT_TYPE, d_name) + sizeof (dp->d_name)); +#endif + *result = memcpy (entry, dp, reclen); +#ifdef GETDENTS_64BIT_ALIGNED + entry->d_reclen = reclen; +#endif + } + else + *result = NULL; + + __libc_lock_unlock (dirp->lock); + + return dp != NULL ? 0 : reclen ? errno : 0; +} + +#ifdef __READDIR_R_ALIAS +weak_alias (__readdir_r, readdir_r) +#endif |