1.\" Copyright (c) 1983, 1990, 1992, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)gcore.1 8.2 (Berkeley) 4/18/94 29.\" $FreeBSD$ 30.\" 31.Dd April 24, 2021 32.Dt GCORE 1 33.Os 34.Sh NAME 35.Nm gcore 36.Nd get core images of running process 37.Sh SYNOPSIS 38.Nm 39.Op Fl f 40.Op Fl k 41.Op Fl c Ar core 42.Op Ar executable 43.Ar pid 44.Sh DESCRIPTION 45The 46.Nm 47utility creates a core image of the specified process, 48suitable for use with 49.Xr gdb 1 . 50By default, the core is written to the file 51.Dq Pa core.<pid> . 52The process identifier, 53.Ar pid , 54must be given on the command line. 55.Pp 56The following options are available: 57.Bl -tag -width indent 58.It Fl c 59Write the core file to the specified file instead of 60.Dq Pa core.<pid> . 61.It Fl f 62Dumps all available segments, excluding only malformed and undumpable 63segments. 64Unlike the default invocation, this flag dumps mappings of devices which 65may invalidate the state of device transactions or trigger other unexpected 66behavior. 67As a result, this flag should only be used when the behavior of the 68application and any devices it has mapped is fully understood and any side 69effects can be controlled or tolerated. 70.It Fl k 71Use the 72.Xr ptrace 2 73.Dv PT_COREDUMP 74kernel facility to write the core dump, instead of reading the process' 75memory and constructing the dump file in 76.Nm 77itself. 78This is faster, and the dump is written by the 79same kernel code that writes core dumps upon fatal signals. 80.El 81.Sh FILES 82.Bl -tag -width /var/log/messages -compact 83.It Pa core.<pid> 84the core image 85.El 86.Sh HISTORY 87A 88.Nm 89utility appeared in 90.Bx 4.2 . 91.Sh BUGS 92Because of the 93.Xr ptrace 2 94usage 95.Nm 96may not work with processes which are actively being investigated with 97.Xr truss 1 98or 99.Xr gdb 1 . 100Additionally, interruptable sleeps may exit with EINTR. 101.Pp 102The 103.Nm 104utility is not compatible with the original 105.Bx 4.2 106version. 107