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.Dd April 24, 2021 29.Dt GCORE 1 30.Os 31.Sh NAME 32.Nm gcore 33.Nd get core images of running process 34.Sh SYNOPSIS 35.Nm 36.Op Fl f 37.Op Fl k 38.Op Fl c Ar core 39.Op Ar executable 40.Ar pid 41.Sh DESCRIPTION 42The 43.Nm 44utility creates a core image of the specified process, 45suitable for use with 46.Xr gdb 1 Pq Pa ports/devel/gdb . 47By default, the core is written to the file 48.Dq Pa core.<pid> . 49The process identifier, 50.Ar pid , 51must be given on the command line. 52.Pp 53The following options are available: 54.Bl -tag -width indent 55.It Fl c 56Write the core file to the specified file instead of 57.Dq Pa core.<pid> . 58.It Fl f 59Dumps all available segments, excluding only malformed and undumpable 60segments. 61Unlike the default invocation, this flag dumps mappings of devices which 62may invalidate the state of device transactions or trigger other unexpected 63behavior. 64As a result, this flag should only be used when the behavior of the 65application and any devices it has mapped is fully understood and any side 66effects can be controlled or tolerated. 67.It Fl k 68Use the 69.Xr ptrace 2 70.Dv PT_COREDUMP 71kernel facility to write the core dump, instead of reading the process' 72memory and constructing the dump file in 73.Nm 74itself. 75This is faster, and the dump is written by the 76same kernel code that writes core dumps upon fatal signals. 77.El 78.Sh FILES 79.Bl -tag -width /var/log/messages -compact 80.It Pa core.<pid> 81the core image 82.El 83.Sh HISTORY 84A 85.Nm 86utility appeared in 87.Bx 4.2 . 88.Sh BUGS 89Because of the 90.Xr ptrace 2 91usage 92.Nm 93may not work with processes which are actively being investigated with 94.Xr truss 1 95or 96.Xr gdb 1 Pq Pa ports/devel/gdb . 97Additionally, interruptable sleeps may exit with EINTR. 98.Pp 99The 100.Nm 101utility is not compatible with the original 102.Bx 4.2 103version. 104