getmountent.3

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· 3 代码 · 共 137 行

.\" SCCSID: @(#)getmountent.3	8.1	9/11/90
.TH getmountent 3
.SH Name
getmountent \- get information about mounted file systems without blocking
.SH Syntax
.nf
.ft B
#include <sys/types.h>
#include <sys/param.h>
#include <sys/mount.h>
.PP
.ft B
getmountent(start, buffer, nentries)
int 		*start;
struct fs_data	*buffer;
int		 nentries;
.fi
.SH Description
.NXR "getmountent subroutine"
.NXA "getmountent subroutine" "statfs subroutine"
.NXR "file system" "getting information on mounted"
The
.PN getmountent
library routine retrieves mounted file system information
from memory without blocking.
The file system information retrieved
(the number of free inodes and blocks)
might not be up to date.
If the accuracy of the file system information retrieved is critical,
you should use
.PN statfs
or
.PN getmnt
instead of
.PN getmountent .
.PP
The 
.I start
argument is the current logical location within the
internal system mount table and
must be initially set to 0.
The
.I buffer
argument is the holding area for the returned information;
that is,
the
.PN fs_data
structures.
The size of
.I buffer
should be at least the number of entries
times the size of the
.PN fs_data
structure,
in bytes.

The
.I nentries
argument defines the number of mount table entries that are to
be retrieved.
.PP
The number of file systems described by the information placed in
.I buffer
is returned.
The
.I start
argument is updated so that successive calls can be used to retrieve
the entire mount table.
.PP
.SH Return Values
.PP
Upon successful completion, a value indicating the number of
.PN struct
.PN fs_data
structures stored in
.I buffer
is returned.
If there are no more file systems in the mount table,
.PN 0
is returned.
Otherwise,
.PN \-1
is returned and the global variable
.I errno
is set to indicate the error.
.\" .LP
.\" Upon successful completion,
.\" a value of 1 is returned.
.\" Otherwise,
.\" .PN \-1
.\" is returned and the variable
.\" .I errno
.\" is set to indicate the error.
.PP
.SH Diagnostics
.\" .TP 15
.\" ENOTDIR
.\" A component of the path prefix of
.\" .I path
.\" is not a directory.
.TP 15
EINVAL
Invalid argument.
.\" .TP 15
.\" ENAMETOOLONG
.\" The length of a component of
.\" .I path
.\" exceeds 255 characters,
.\" or the length of
.\" .I path
.\" exceeds 1023 characters.
.\" .TP 15
.\" ENOENT
.\" The file referred to by
.\" .I path
.\" does not exist.
.\" .TP 15
.\" EACCESS
.\" Search permission is denied for a component of the path prefix of
.\" .IR path .
.TP 15
.\" ELOOP
.\" Too many symbolic links were encountered in translating
.\" .IR path .
.TP 15
EFAULT
Either
.I buffer
or
.I start
causes an illegal address to be referenced.
.TP 15
EIO
An I/O error occurred while reading from the file system.
.SH See Also
getmnt(2), statfs(3)