My application requires the core dump file to be generated in a specific pattern. I want the core file generated with file name in a given format (which contains PID of the process, etc). This can be done by setting the pattern in /proc/sys/kernel/core_pattern. using specifiers like %p, %e. But this method will affect the core file pattern globally. I don't want this to happen. I'm not allowed to change the core pattern of other processes and others' processes.
How do I do this without affecting other processes?
And how do I do this when /proc is read-only?
man core
tells us:
Piping core dumps to a program
Since kernel 2.6.19, Linux supports an alternate syntax for the
/proc/sys/kernel/core_pattern
file. If the first character of this file is a pipe symbol (|
), then the remainder of the line is interpreted as a program to be executed. Instead of being written to a disk file, the core dump is given as standard input to the program.Note the following points:
The program must be specified using an absolute pathname (or a pathname relative to the root directory, /), and must immediately follow the '|' character.
The process created to run the program runs as user and group root.
Command-line arguments can be supplied to the program (since Linux 2.6.24), delimited by white space (up to a total line length of 128 bytes).
The command-line arguments can include any of the % specifiers listed above. For example, to pass the PID of the process that is being dumped, specify %p in an argument.
You can put a script there, like e.g.
| /path/to/myscript %p %s %c
You can detect which process is triggering the coredump: (man core
):
%% a single % character
%p PID of dumped process
%u (numeric) real UID of dumped process
%g (numeric) real GID of dumped process
%s number of signal causing dump
%t time of dump, expressed as seconds since the Epoch, 1970-01-01
00:00:00 +0000 (UTC)
%h hostname (same as nodename returned by uname(2))
%e executable filename (without path prefix)
%E pathname of executable, with slashes ('/') replaced by exclama‐
tion marks ('!').
%c core file size soft resource limit of crashing process (since
Linux 2.6.24)
Now all you have to do is "do the default thing" for other processes than your own