.\" Copyright (c) 2011 Sergey Kandaurov
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.Dd May 3, 2014
.Dt PGET 9
.Os
.Sh NAME
.Nm pget
.Nd locate a process by number
.Sh SYNOPSIS
.In sys/param.h
.In sys/proc.h
.Ft int
.Fn pget "pid_t pid" "int flags" "struct proc **pp"
.Sh DESCRIPTION
This function
takes a
.Fa pid
as its argument,
which can be either a process or thread id,
and fills a pointer to the
.Vt proc
structure in
.Fa *pp .
In the latter case, a process owning the specified thread is looked for.
The operation is performed by invoking the
.Xr pfind 9
function.
The found process is returned locked.
For the
.Dv PGET_HOLD
case, it is returned unlocked (but held).
The
.Fn pget
function can
perform additional manipulations, depending on a
.Fa flags
argument.
.Pp
The
.Fa flags
argument is the logical OR of some subset of:
.Bl -tag -width ".Dv PGET_NOTINEXEC"
.It Dv PGET_HOLD
If set, the found process will be held and unlocked.
.It Dv PGET_CANSEE
If set, the found process will be checked for its visibility.
See
.Xr p_cansee 9 .
.It Dv PGET_CANDEBUG
If set, the found process will be checked for its debuggability.
See
.Xr p_candebug 9 .
.It Dv PGET_ISCURRENT
If set, the found process will be checked that it matches the current
process context.
.It Dv PGET_NOTWEXIT
If set, the found process will be checked that it does not have the process
flag
.Dv P_WEXIT
set.
.It Dv PGET_NOTINEXEC
If set, the found process will be checked that it does not have the process
flag
.Dv P_INEXEC
set.
.It Dv PGET_NOTID
If set,
.Fa pid
is not assumed as a thread id for values larger than
.Dv PID_MAX .
.It Dv PGET_WANTREAD
If set, the found process will be checked that the caller may get
a read access to its structure.
A shorthand for
.Pq Dv PGET_HOLD | PGET_CANDEBUG | PGET_NOTWEXIT .
.El
.Sh RETURN VALUES
If the process is found in the specified way, then zero is returned,
otherwise an appropriate error code is returned.
.Sh SEE ALSO
.Xr p_candebug 9 ,
.Xr p_cansee 9 ,
.Xr pfind 9