On 8/12/19 3:18 AM, Jeremy Nicoll - ml fedora wrote:
On 2019-08-12 02:01, Sam Varshavchik wrote:
> ToddAndMargo via users writes:
>> What does this do?
>>
>> # echo core > /proc/sys/kernel/core_pattern
> This will, instead, create a plain file called
> "core" in the executable's directory.
Excuse my interruption, but why would that create a file named
'core'? Why doesn't it just place 'core' in the named file?
That's not a real file. It's part of a virtual filesystem called
"procfs" which gives a filesystem interface to the kernel internal
settings. If you run "mount" you will see a lot of mountpoints that
have types that aren't real filesystems. In fact, most of them are not.
(I was surprised by that when I checked right now.) /proc and /sys
are the top-level mountpoints for most of them. One thing that shows
they are not real files is that everything shows a size of 0 and the
modification date is now.
# cat /proc/sys/kernel/core_pattern
|/usr/lib/systemd/systemd-coredump %P %u %g %s %t %c %h %e
but
# ls -l /proc/sys/kernel/core_pattern
-rw-r--r--. 1 root root 0 Aug 12 12:51 /proc/sys/kernel/core_pattern