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mount, umount - Mounts or unmounts a file system using the System V
int datalen );
int umount (const
Points to a path name that is a removable file system contained on the
block special file.
dir Points to a path name that is the directory on which spec is mounted.
Specifies whether additional file system data is included. The valid
flag is MS_DATA.
Specifies the file system type number.
Points to the address of a block of file system specific data.
Specifies the length of the file system specific data.
Points to a null-terminated string containing the appropriate pathname.
The mount() function mounts a removable file system contained on the block
special file identified by spec. The dir argument identifies the mount
When the MS_DATA flag bit of mflag is off, the file system type defaults to
the root file system type. Only when the MS_DATA flag bit is on, should you
use the fstyp argument to indicate the file system type. Also, the dataptr
and datalen arguments, which describe a block of file system specific data,
must be present when the MS_DATA flag is set. The file system specific code
within the operating system interprets the data. The data's format depends
on the file system type. If a file system type does not require this data,
dataptr and datalen should both be zero.
Use the low-order bit of mflag to control write permission on the mounted
file system. If the low-order bit is 1, writing is forbidden; otherwise,
writing is permitted according to individual file accessibility.
After a successful mount(), references to the dir file refer to the mounted
file system's root directory.
The umount() function unmounts a file system mounted at the directory
pointed to the mnt-path parameter. The associated directory reverts to its
Except for file-on-file mounting, to call either the mount() and umount()
function, the calling process must have superuser privilege.
Two mount() functions are supported by Tru64 UNIX: the BSD mount() and the
System V mount(). The BSD function is the default mount() and it is
documented in mount(2). To use the System V version of mount(), documented
here you must link with the libsys5 library before you link with the libc
library or be in the System V habitat.
The mount command supports mount point argument pathnames of up to
MNAMELEN, which includes the null terminating character. MNAMELEN can be
up to 90 characters long, including the null terminating character.
The mount() function returns 0 when the file system is successfully
mounted. Otherwise, -1 is returned and errno is set to indicate the error.
If the mount() function fails, errno may be set to one of the following
The effective user ID is not super-user.
Any of the named files does not exist.
A component of a path prefix is not a directory.
The file system identified by spec is remote and cannot be mounted.
The path argument points to a remote machine and the link to that
machine is no longer active.
Components of path require hopping to multiple remote machines.
The spec argument is not a block special device.
The device associated with spec does not exist.
The dir argument is not a directory.
The spec or dir argument points outside the allocated address space of
The dir argument is a user's current working directory, is mounted on a
user's current working directory, or is otherwise busy.
The device associated with spec is currently mounted.
There are no more mount table entries.
The spec is write protected and mflag requests write permission.
The file system state in the super-block is not FsOKAY and mflag
requests write permission.
The super block has an invalid magic number or the fstyp is invalid or
mflag is not valid.
If the umount() function fails, errno may be set to one of the following
The caller does not have appropriate privilege.
A component of the path is not a directory.
The pathname contains a character with the high-order bit set.
A component of a pathname exceeded NAME_MAX characters, or an entire
pathname exceeded PATH_MAX characters.
Too many symbolic links were encountered in translating the pathname.
The requested directory is not in the mount table.
A process is holding a reference to a file located on the file system.
An I/O error occurred while writing cached file system information.
The mnt-path parameter points outside the process' allocated address
The device identified by the mnt-path does not exist.
The named file does not exist.
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