Hello Jonny, On 5/27/20 5:22 PM, Jonny Grant wrote: > > > On 27/05/2020 14:32, Michael Kerrisk (man-pages) wrote: >> Hi Jonny >> >> On Wed, 27 May 2020 at 15:23, Jonny Grant <jg@xxxxxxxx> wrote: >>> >>> >>> >>> On 27/05/2020 14:06, Michael Kerrisk (man-pages) wrote: >>>> Hi Jonny, >>>> >>>> On Mon, 25 May 2020 at 17:08, Jonny Grant <jg@xxxxxxxx> wrote: >>>>> >>>>> Suggestion for some additional information on this page: >>>>> >>>>> http://man7.org/linux/man-pages/man5/core.5.html >>>>> >>>>> Could "Core dumps and systemd" be extended to give an >>>>> example of sysctl making a temporary change? >>>>> >>>>> eg set to the filename and signal that causes the core dump: >>>>> >>>>> # sysctl -w kernel.core_pattern="%e-%s.core" >>>> >>>> I'm a little confused: what do you mean by "making a *temporary* >>>> change" (i.e., where does "temporary" come into it)? >>>> >>>> Thanks, >>>> >>>> Michael >>>> >>> >>> As I understood, this core pattern is set until reboot. >> >> Okay, now I understand. Next question: what's the value in having the >> signal number in the filename? > > The signal number indicates the reason the core was dumped, > eg 11 SIGSEGV, SIGTRAP is 5. Sure, it tells us what signal triggered the core dump. My reason for the question was that it doesn't tell us the *reason* for the core dump--for example, SIGSEGV can be generated for many reasons. > %P %t %I also useful. Okay. I applied the patch below. Thanks, Michael diff --git a/man5/core.5 b/man5/core.5 index 9725ff64a..6dbaa69b8 100644 --- a/man5/core.5 +++ b/man5/core.5 @@ -533,7 +533,7 @@ For more extensive details, see the .BR coredumpctl (1) manual page. .PP -To disable the +To (persistently) disable the .BR systemd (1) mechanism that archives core dumps, restoring to something more like traditional Linux behavior, one can set an override for the @@ -548,6 +548,18 @@ mechanism, using something like: .EE .in .PP +It is also possible to temporarily (i.e., until the next reboot) change the +.I core_patter +setting using a command such as the following +(which causes the names of core dump files to include the executable name +as well as the number of the signal which triggered the core dump): +.PP +.in +4n +.EX +# \fBsysctl \-w kernel.core_pattern="%e\-%s.core"\fP +.EE +.in +.PP .\" .SH NOTES The -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/
