изменить режим файла (change mode of a 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)
fchmod — change mode of a file
Синопсис (Synopsis)
#include <sys/stat.h>
int fchmod(int fildes, mode_t mode);
Описание (Description)
The fchmod() function shall be equivalent to chmod() except that
the file whose permissions are changed is specified by the file
descriptor fildes.
If fildes references a shared memory object, the fchmod()
function need only affect the S_IRUSR, S_IWUSR, S_IRGRP, S_IWGRP,
S_IROTH, and S_IWOTH file permission bits.
If fildes references a typed memory object, the behavior of
fchmod() is unspecified.
If fildes refers to a socket, the behavior of fchmod() is
unspecified.
If fildes refers to a STREAM (which is fattach()-ed into the file
system name space) the call returns successfully, doing nothing.
Возвращаемое значение (Return value)
Upon successful completion, fchmod() shall return 0. Otherwise,
it shall return -1 and set errno to indicate the error.
Ошибки (Error)
The fchmod() function shall fail if:
EBADF The fildes argument is not an open file descriptor.
EPERM The effective user ID does not match the owner of the file
and the process does not have appropriate privileges.
EROFS The file referred to by fildes resides on a read-only file
system.
The fchmod() function may fail if:
EINTR The fchmod() function was interrupted by a signal.
EINVAL The value of the mode argument is invalid.
EINVAL The fildes argument refers to a pipe and the
implementation disallows execution of fchmod() on a pipe.
The following sections are informative.
Примеры (Examples)
Changing the Current Permissions for a File
The following example shows how to change the permissions for a
file named /home/cnd/mod1 so that the owner and group have
read/write/execute permissions, but the world only has read/write
permissions.
#include <sys/stat.h>
#include <fcntl.h>
mode_t mode;
int fildes;
...
fildes = open("/home/cnd/mod1", O_RDWR);
fchmod(fildes, S_IRWXU | S_IRWXG | S_IROTH | S_IWOTH);
Использование в приложениях (Application usage)
None.
Обоснование (Rationale)
None.
Будущие направления (Future directions)
None.
Смотри также (See also)
chmod(3p), chown(3p), creat(3p), fcntl(3p), fstatat(3p),
fstatvfs(3p), mknod(3p), open(3p), read(3p), write(3p)
The Base Definitions volume of POSIX.1‐2017, sys_stat.h(0p)
