переименуйте файл (rename file)
Пролог (Prolog)
This manual page is part of the POSIX Programmer's Manual. The
Linux implementation of this interface may differ (consult the
corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
Имя (Name)
rename, renameat — rename file
Синопсис (Synopsis)
#include <stdio.h>
int rename(const char *old, const char *new);
#include <fcntl.h>
int renameat(int oldfd, const char *old, int newfd,
const char *new);
Описание (Description)
For rename(): The functionality described on this reference page
is aligned with the ISO C standard. Any conflict between the
requirements described here and the ISO C standard is
unintentional. This volume of POSIX.1‐2017 defers to the ISO C
standard.
The rename() function shall change the name of a file. The old
argument points to the pathname of the file to be renamed. The
new argument points to the new pathname of the file. If the new
argument does not resolve to an existing directory entry for a
file of type directory and the new argument contains at least one
non-<slash> character and ends with one or more trailing <slash>
characters after all symbolic links have been processed, rename()
shall fail.
If either the old or new argument names a symbolic link, rename()
shall operate on the symbolic link itself, and shall not resolve
the last component of the argument. If the old argument and the
new argument resolve to either the same existing directory entry
or different directory entries for the same existing file,
rename() shall return successfully and perform no other action.
If the old argument points to the pathname of a file that is not
a directory, the new argument shall not point to the pathname of
a directory. If the link named by the new argument exists, it
shall be removed and old renamed to new. In this case, a link
named new shall remain visible to other threads throughout the
renaming operation and refer either to the file referred to by
new or old before the operation began. Write access permission is
required for both the directory containing old and the directory
containing new.
If the old argument points to the pathname of a directory, the
new argument shall not point to the pathname of a file that is
not a directory. If the directory named by the new argument
exists, it shall be removed and old renamed to new. In this
case, a link named new shall exist throughout the renaming
operation and shall refer either to the directory referred to by
new or old before the operation began. If new names an existing
directory, it shall be required to be an empty directory.
If either pathname argument refers to a path whose final
component is either dot or dot-dot, rename() shall fail.
If the old argument points to a pathname of a symbolic link, the
symbolic link shall be renamed. If the new argument points to a
pathname of a symbolic link, the symbolic link shall be removed.
The old pathname shall not name an ancestor directory of the new
pathname. Write access permission is required for the directory
containing old and the directory containing new. If the old
argument points to the pathname of a directory, write access
permission may be required for the directory named by old, and,
if it exists, the directory named by new.
If the link named by the new argument exists and the file's link
count becomes 0 when it is removed and no process has the file
open, the space occupied by the file shall be freed and the file
shall no longer be accessible. If one or more processes have the
file open when the last link is removed, the link shall be
removed before rename() returns, but the removal of the file
contents shall be postponed until all references to the file are
closed.
Upon successful completion, rename() shall mark for update the
last data modification and last file status change timestamps of
the parent directory of each file.
If the rename() function fails for any reason other than [EIO],
any file named by new shall be unaffected.
The renameat() function shall be equivalent to the rename()
function except in the case where either old or new specifies a
relative path. If old is a relative path, the file to be renamed
is located relative to the directory associated with the file
descriptor oldfd instead of the current working directory. If new
is a relative path, the same happens only relative to the
directory associated with newfd. If the access mode of the open
file description associated with the file descriptor is not
O_SEARCH, the function shall check whether directory searches are
permitted using the current permissions of the directory
underlying the file descriptor. If the access mode is O_SEARCH,
the function shall not perform the check.
If renameat() is passed the special value AT_FDCWD in the oldfd
or newfd parameter, the current working directory shall be used
in the determination of the file for the respective path
parameter.
Возвращаемое значение (Return value)
Upon successful completion, the rename() function shall return 0.
Otherwise, it shall return -1, errno shall be set to indicate the
error, and neither the file named by old nor the file named by
new shall be changed or created.
Upon successful completion, the renameat() function shall return
0. Otherwise, it shall return -1 and set errno to indicate the
error.
Ошибки (Error)
The rename() and renameat() functions shall fail if:
EACCES A component of either path prefix denies search
permission; or one of the directories containing old or
new denies write permissions; or, write permission is
required and is denied for a directory pointed to by the
old or new arguments.
EBUSY The directory named by old or new is currently in use by
the system or another process, and the implementation
considers this an error.
[EEXIST] or [ENOTEMPTY]
The link named by new is a directory that is not an
empty directory.
EINVAL The old pathname names an ancestor directory of the
new pathname, or either pathname argument contains a
final component that is dot or dot-dot.
EIO A physical I/O error has occurred.
EISDIR The new argument points to a directory and the old
argument points to a file that is not a directory.
ELOOP A loop exists in symbolic links encountered during
resolution of the path argument.
EMLINK The file named by old is a directory, and the link
count of the parent directory of new would exceed
{LINK_MAX}.
ENAMETOOLONG
The length of a component of a pathname is longer
than {NAME_MAX}.
ENOENT The link named by old does not name an existing file,
a component of the path prefix of new does not exist,
or either old or new points to an empty string.
ENOSPC The directory that would contain new cannot be
extended.
ENOTDIR A component of either path prefix names an existing
file that is neither a directory nor a symbolic link
to a directory; or the old argument names a directory
and the new argument names a non-directory file; or
the old argument contains at least one non-<slash>
character and ends with one or more trailing <slash>
characters and the last pathname component names an
existing file that is neither a directory nor a
symbolic link to a directory; or the old argument
names an existing non-directory file and the new
argument names a nonexistent file, contains at least
one non-<slash> character, and ends with one or more
trailing <slash> characters; or the new argument
names an existing non-directory file, contains at
least one non-<slash> character, and ends with one or
more trailing <slash> characters.
EPERM or EACCES
The S_ISVTX flag is set on the directory containing
the file referred to by old and the process does not
satisfy the criteria specified in the Base
Definitions volume of POSIX.1‐2017, Section 4.3,
Directory Protection with respect to old; or new
refers to an existing file, the S_ISVTX flag is set
on the directory containing this file, and the
process does not satisfy the criteria specified in
the Base Definitions volume of POSIX.1‐2017, Section
4.3, Directory Protection with respect to this file.
EROFS The requested operation requires writing in a
directory on a read-only file system.
EXDEV The links named by new and old are on different file
systems and the implementation does not support links
between file systems.
In addition, the renameat() function shall fail if:
EACCES The access mode of the open file description associated
with oldfd or newfd is not O_SEARCH and the permissions of
the directory underlying oldfd or newfd, respectively, do
not permit directory searches.
EBADF The old argument does not specify an absolute path and the
oldfd argument is neither AT_FDCWD nor a valid file
descriptor open for reading or searching, or the new
argument does not specify an absolute path and the newfd
argument is neither AT_FDCWD nor a valid file descriptor
open for reading or searching.
ENOTDIR
The old or new argument is not an absolute path and oldfd
or newfd, respectively, is a file descriptor associated
with a non-directory file.
The rename() and renameat() functions may fail if:
EBUSY The file named by the old or new arguments is a named
STREAM.
ELOOP More than {SYMLOOP_MAX} symbolic links were encountered
during resolution of the path argument.
ENAMETOOLONG
The length of a pathname exceeds {PATH_MAX}, or pathname
resolution of a symbolic link produced an intermediate
result with a length that exceeds {PATH_MAX}.
ETXTBSY
The file named by new exists and is the last directory
entry to a pure procedure (shared text) file that is being
executed.
The following sections are informative.
Примеры (Examples)
Renaming a File
The following example shows how to rename a file named
/home/cnd/mod1 to /home/cnd/mod2.
#include <stdio.h>
int status;
...
status = rename("/home/cnd/mod1", "/home/cnd/mod2");
Использование в приложениях (Application usage)
Some implementations mark for update the last file status change
timestamp of renamed files and some do not. Applications which
make use of the last file status change timestamp may behave
differently with respect to renamed files unless they are
designed to allow for either behavior.
Обоснование (Rationale)
This rename() function is equivalent for regular files to that
defined by the ISO C standard. Its inclusion here expands that
definition to include actions on directories and specifies
behavior when the new parameter names a file that already exists.
That specification requires that the action of the function be
atomic.
One of the reasons for introducing this function was to have a
means of renaming directories while permitting implementations to
prohibit the use of link() and unlink() with directories, thus
constraining links to directories to those made by mkdir().
The specification that if old and new refer to the same file is
intended to guarantee that:
rename("x", "x");
does not remove the file.
Renaming dot or dot-dot is prohibited in order to prevent
cyclical file system paths.
See also the descriptions of [ENOTEMPTY] and [ENAMETOOLONG] in
rmdir() and [EBUSY] in unlink(). For a discussion of [EXDEV],
see link().
The purpose of the renameat() function is to rename files in
directories other than the current working directory without
exposure to race conditions. Any part of the path of a file could
be changed in parallel to a call to rename(), resulting in
unspecified behavior. By opening file descriptors for the source
and target directories and using the renameat() function it can
be guaranteed that that renamed file is located correctly and the
resulting file is in the desired directory.
Будущие направления (Future directions)
None.
Смотри также (See also)
link(3p), rmdir(3p), symlink(3p), unlink(3p)
The Base Definitions volume of POSIX.1‐2017, Section 4.3,
Directory Protection, fcntl.h(0p), stdio.h(0p)
