The UNIX file system option provides support for a disk-based file system, namely, the file system resides on physical media such as hard disks.
The UNIX file system option supports drivers for the following types of physical media:
SCSI disks
IDE disks
RAM disks
The UFS feature provides POSIX-compatible file I/O system calls on top of the UFS file system on a local disk. Thus, it requires a local disk to be configured and accessible on the target system. At least one of the RAM_DISK, or SCSI_DISK features must be configured. UFS must be embedded in any configuration that exports local files through NFS.
The UFS feature API is identical to the API exported by the NFS_CLIENT feature. However, some system calls in this API will return with error codes since the underlying file system layout does not support all these operations. For general information on the API provided by this feature, see the POSIX standard (IEEE Std 1003.1b-1993).
The UFS feature API is summarized in the following table. It is identical to the API exported by the NFS_CLIENT feature. However, some system calls in this API will return with error codes since the underlying file system layout does not support all these operations. For general information on the API provided by this feature, see the POSIX standard (IEEE Std 1003.1b-1993). Some of the calls listed are also included in other features.
Command |
Description |
---|---|
access |
Check access permissions |
chdir, fchdir |
Change current directory |
chflags |
Modify file flags (BSD command) |
chmod, fchmod |
Change access mode |
chown, fchown |
Change owner |
chroot |
Change root directory |
close |
Close a file descriptor |
dup, dup2 |
Duplicate an open file descriptor |
fcntl |
File control |
flock |
Apply or remove an advisory lock on an open file |
fpathconf |
Get configurable pathname variables |
fsync |
Synchronize a file's in-core statistics with those on disk |
getdents |
Read directory entries |
getdirentries |
Get directory entries in a file system independent format |
getfsstat |
Get list of all mounted file systems |
ioctl |
Device control |
link |
Make a hard file link |
lseek |
Move read/write file pointer |
mkdir |
Make a directory file |
mkfifo |
Make FIFOs |
mknod |
Create a special file |
mount, umount |
Mount or unmount a file system |
open |
Open for reading or writing |
read, readv |
Read from file |
readlink |
Read a value of a symbolic link |
rename |
Change the name of a file |
revoke |
Invalidate all open file descriptors (BSD command) |
rmdir |
Remove a directory file |
stat, fstat, lstat |
Get file status |
statfs, fstatfs |
Get file system statistics |
symlink |
Make a symbolic link to a file |
sync |
Synchronize disk block in-core status with that on disk |
truncate, ftruncate |
Truncate a file |
umask |
Set file creation mode mask |
unlink |
Remove a directory entry |
utimes |
Set file access and modification times |
write, writev |
Write to a file |
The following library calls do not support multithreaded applications:
Function |
Description |
---|---|
opendir() |
Open a directory |
closedir() |
Close a directory |
readdir() |
Read directory entry |
rewinddir() |
Reset directory stream |
scandir() |
Scan a directory for matching entries |
seekdir() |
Set the position of the next readdir() call in the directory stream |
telldir() |
Return current location in directory stream |