Copyright (c) 2003 Joseph Koshy <jkoshy@FreeBSD.org>
Copyright (c) 2006 Ceri Davies <ceri@FreeBSD.org>
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$FreeBSD: releng/10.2/share/man/man9/p_cansee.9 208291 2010-05-19 08:57:53Z uqs $
.Dd November 19, 2006 .Dt P_CANSEE 9 .Os .Sh NAME .Nm p_cansee .Nd determine visibility of a process .Sh SYNOPSIS n sys/param.h n sys/proc.h .Ft int .Fn p_cansee "struct thread *td" "struct proc *p" .Sh DESCRIPTION This function can be used to determine if a given process .Fa p is visible to the thread .Fa td , where the notion of .Dq visibility may be read as .Dq "awareness of existence" .
p The function is implemented using .Xr cr_cansee 9 , and the dependencies on .Xr sysctl 8 variables documented in the .Xr cr_cansee 9 manual page apply. .Sh RETURN VALUES The .Fn p_cansee function returns .Li 0 if the process denoted by .Fa p is visible by thread .Fa td , or a non-zero error return value otherwise. .Sh ERRORS l -tag -width Er t Bq Er ESRCH Process .Fa p is not visible to thread .Fa td as determined by .Xr cr_cansee 9 . t Bq Er ESRCH Thread .Fa td has been jailed and process .Fa p does not belong to the same jail as .Fa td . t Bq Er ESRCH The MAC subsystem denied visibility. .El .Sh SEE ALSO .Xr jail 2 , .Xr sysctl 8 , .Xr cr_cansee 9 , .Xr mac 9 , .Xr p_candebug 9 , .Xr prison_check 9