What does '|' mean in file /proc/sys/kernel/core_pattern?

Question

$ cat /proc/sys/kernel/core_pattern
|/usr/share/apport/apport %p %s %c %d %P

What does '|' mean in file /proc/sys/kernel/core_pattern?

Answer 1

In the linux kernel documentation /usr/src/linux/Documentation/sysctl/kernel.txt.

[/proc/sys/kernel/]core_pattern is used to specify a core dumpfile pattern name.

• If the first character of the pattern is a '|', the kernel will treat the rest of the pattern as a command to run. The core dump will be written to the standard input of that program instead of to a file.