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NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUE | STANDARDS | HISTORY | EXAMPLES | SEE ALSO | COLOPHON |
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FAT_IOCTL_SET_ATTRIBUTES(2const) FAT_IOCTL_SET_ATTRIBUTES(2const)
FAT_IOCTL_GET_ATTRIBUTES, FAT_IOCTL_SET_ATTRIBUTES - get and set
file attributes in a FAT filesystem
Standard C library (libc, -lc)
#include <linux/msdos_fs.h> /* Definition of FAT_* and
ATTR_* constants */
#include <sys/ioctl.h>
int ioctl(int fd, FAT_IOCTL_GET_ATTRIBUTES, uint32_t *attr);
int ioctl(int fd, FAT_IOCTL_SET_ATTRIBUTES, uint32_t *attr);
Files and directories in the FAT filesystem possess an attribute
bit mask that can be read with FAT_IOCTL_GET_ATTRIBUTES and
written with FAT_IOCTL_SET_ATTRIBUTES.
The fd argument contains a file descriptor for a file or
directory. It is sufficient to create the file descriptor by
calling open(2) with the O_RDONLY flag.
The attr argument contains a pointer to a bit mask. The bits of
the bit mask are:
ATTR_RO
This bit specifies that the file or directory is read-
only.
ATTR_HIDDEN
This bit specifies that the file or directory is hidden.
ATTR_SYS
This bit specifies that the file is a system file.
ATTR_VOLUME
This bit specifies that the file is a volume label. This
attribute is read-only.
ATTR_DIR
This bit specifies that this is a directory. This
attribute is read-only.
ATTR_ARCH
This bit indicates that this file or directory should be
archived. It is set when a file is created or modified.
It is reset by an archiving system.
The zero value ATTR_NONE can be used to indicate that no
attribute bit is set.
On success, 0 is returned. On error, -1 is returned, and errno
is set to indicate the error.
Linux.
Linux 2.6.12.
The following program demonstrates the usage of ioctl(2) to
manipulate file attributes. The program reads and displays the
archive attribute of a file. After inverting the value of the
attribute, the program reads and displays the attribute again.
The following was recorded when applying the program for the file
/mnt/user/foo:
# ./toggle_fat_archive_flag /mnt/user/foo
Archive flag is set
Toggling archive flag
Archive flag is not set
Program source (toggle_fat_archive_flag.c)
#include <fcntl.h>
#include <linux/msdos_fs.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <unistd.h>
/*
* Read file attributes of a file on a FAT filesystem.
* Output the state of the archive flag.
*/
static uint32_t
readattr(int fd)
{
int ret;
uint32_t attr;
ret = ioctl(fd, FAT_IOCTL_GET_ATTRIBUTES, &attr);
if (ret == -1) {
perror("ioctl");
exit(EXIT_FAILURE);
}
if (attr & ATTR_ARCH)
printf("Archive flag is set\n");
else
printf("Archive flag is not set\n");
return attr;
}
int
main(int argc, char *argv[])
{
int fd;
int ret;
uint32_t attr;
if (argc != 2) {
printf("Usage: %s FILENAME\n", argv[0]);
exit(EXIT_FAILURE);
}
fd = open(argv[1], O_RDONLY);
if (fd == -1) {
perror("open");
exit(EXIT_FAILURE);
}
/*
* Read and display the FAT file attributes.
*/
attr = readattr(fd);
/*
* Invert archive attribute.
*/
printf("Toggling archive flag\n");
attr ^= ATTR_ARCH;
/*
* Write the changed FAT file attributes.
*/
ret = ioctl(fd, FAT_IOCTL_SET_ATTRIBUTES, &attr);
if (ret == -1) {
perror("ioctl");
exit(EXIT_FAILURE);
}
/*
* Read and display the FAT file attributes.
*/
readattr(fd);
close(fd);
exit(EXIT_SUCCESS);
}
ioctl(2), ioctl_fat(2)
This page is part of the man-pages (Linux kernel and C library
user-space interface documentation) project. Information about
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⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.
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2024-06-26. If you discover any rendering problems in this HTML
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man-pages@man7.org
Linux man-pages 6.9.1 2024-06-15FAT_IOCTL_SET_ATTRIBUTES(2const)
Pages that refer to this page: ioctl_fat(2)
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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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