.\"	$OpenBSD: kvm_getfiles.3,v 1.19 2016/05/04 01:32:04 zhuk Exp $
.\"	$NetBSD: kvm_getfiles.3,v 1.3 1996/03/18 22:33:23 thorpej Exp $
.\"
.\" Copyright (c) 1992, 1993
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.\" This code is derived from software developed by the Computer Systems
.\" Engineering group at Lawrence Berkeley Laboratory under DARPA contract
.\" BG 91-66 and contributed to Berkeley.
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.\"     @(#)kvm_getfiles.3	8.2 (Berkeley) 4/19/94
.\"
.Dd $Mdocdate: May 4 2016 $
.Dt KVM_GETFILES 3
.Os
.Sh NAME
.Nm kvm_getfiles
.Nd survey open files
.Sh SYNOPSIS
.In kvm.h
.In sys/types.h
.In sys/sysctl.h
.Ft struct kinfo_file *
.Fn kvm_getfiles "kvm_t *kd" "int op" "int arg" "size_t elemsize" "int *cnt"
.Sh DESCRIPTION
.Fn kvm_getfiles
returns a (sub-)set of the open files in the kernel indicated by
.Fa kd .
The
.Fa op
and
.Fa arg
arguments constitute a predicate which limits the set of files
returned.
The value of
.Fa op
describes the filtering predicate as follows:
.Pp
.Bl -tag -width 20n -offset indent -compact
.It Dv KERN_FILE_BYFILE
all open files with type
.Fa arg
(0 for all files)
.It Dv KERN_FILE_BYPID
files opened by process ID
.Fa arg
(\-1 for all processes)
.It Dv KERN_FILE_BYUID
files opened by processes with effective user ID
.Fa arg
(\-1 for all users)
.El
.Pp
Files associated with a process will include information about
the process that has the file open.
.Pp
For
.Dv KERN_FILE_BYFILE
the recognized file types are defined in
.In sys/file.h :
.Pp
.Bl -tag -width 20n -offset indent -compact
.It Dv DTYPE_VNODE
files and devices
.It Dv DTYPE_SOCKET
sockets, regardless of domain
.It Dv DTYPE_PIPE
pipes and FIFOs
.It Dv DTYPE_KQUEUE
kqueues
.El
.Pp
Only the first
.Fa elemsize
bytes of each array entry are returned.
If the size of the
.Vt kinfo_file
structure increases in size in a future release of
.Ox ,
the kernel will only return the requested amount of data for
each array entry and programs that use
.Fn kvm_getfiles
will continue to function without the need for recompilation.
.Sh RETURN VALUES
The files are returned as a contiguous array of
.Vt kinfo_file
structures.
The number of structures found is returned in the reference parameter
.Fa cnt .
This memory is owned by kvm and will be overwritten by subsequent calls to
.Fn kvm_getfiles
and destroyed by
.Fn kvm_close .
Data should be copied out if it needs to be saved.
.Pp
.Fn kvm_getfiles
will return
.Dv NULL
on failure.
.Sh ERRORS
.Fn kvm_getfiles
will fail if:
.Bl -tag -width Er
.It Bq Er ENOMEM
Could not allocate enough memory for internal buffer.
.It Bq Er ESRCH
The
.Fa op
argument has
.Dv KERN_FILE_BYPID
value and the process specified by
.Fa arg
was not found.
.El
.Sh SEE ALSO
.Xr kvm 3 ,
.Xr kvm_geterr 3 ,
.Xr kvm_nlist 3 ,
.Xr kvm_open 3 ,
.Xr kvm_read 3
.Sh BUGS
This routine does not belong in the kvm interface.