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.\"	@(#)gcore.1	8.2 (Berkeley) 4/18/94
.\" $FreeBSD$
.\"
.Dd July 13, 2016
.Dt GCORE 1
.Os
.Sh NAME
.Nm gcore
.Nd get core images of running process
.Sh SYNOPSIS
.Nm
.Op Fl f
.Op Fl c Ar core
.Op Ar executable
.Ar pid
.Sh DESCRIPTION
The
.Nm
utility creates a core image of the specified process,
suitable for use with
.Xr gdb 1 .
By default, the core is written to the file
.Dq Pa core.<pid> .
The process identifier,
.Ar pid ,
must be given on the command line.
.Pp
The following options are available:
.Bl -tag -width indent
.It Fl c
Write the core file to the specified file instead of
.Dq Pa core.<pid> .
.It Fl f
Dumps all available segments, excluding only malformed and undumpable segments.
Unlike the default invocation, this flag dumps mappings of devices which
may invalidate the state of device transactions or trigger other unexpected
behavior.
As a result, this flag should only be used when the behavior of the
application and any devices it has mapped is fully understood and any side
effects can be controlled or tolerated.
.El
.Sh FILES
.Bl -tag -width /var/log/messages -compact
.It Pa core.<pid>
the core image
.El
.Sh HISTORY
A
.Nm
utility appeared in
.Bx 4.2 .
.Sh BUGS
Because of the
.Xr ptrace 2
usage
.Nm
may not work with processes which are actively being investigated with
.Xr truss 1
or
.Xr gdb 1 .
Additionally, interruptable sleeps may exit with EINTR.
.Pp
The
.Nm
utility is not compatible with the original
.Bx 4.2
version.