msantos / pdeathsigexec

signal process when parent exits

SYNOPSIS

pdeathsigexec cmd ...

DESCRIPTION

pdeathsigexec: signal process when parent exits

A subprocess whose parent exits can be re-parented to init (PID 1) and continue to run. pdeathsigexec sets the process to have a signal sent if the parent process terminates.

The "signal on parent termination" behaviour applies to the executed process only and not descendents (prctl(2)):

The parent-death signal setting is cleared for the child of a fork(2).
It is also (since Linux 2.4.36 / 2.6.23) cleared when  executing  a
set-user-ID or set-group-ID binary, or a binary that has associated
capabilities (see capabilities(7)); otherwise, this value is preserved
across execve(2).

The behaviour can be set for related, dynamically linked processes in a supervision tree by using a LD_PRELOAD library (see EXAMPLES).

EXAMPLES

$ sh -c "sleep inf" &
[1] 25880
$ kill -9 25880
$ pgrep -fa sleep
25882 sleep inf

pdeathsigexec

$ sh -c "pdeathsigexec sleep inf" &
[1] 25926
$ kill -9 25926
$ pgrep -fa sleep
<no output>

libpdeathsigexec

$ LD_PRELOAD=libpdeathsigexec.so sh -c 'sh -c "sleep inf" & sleep inf' &
[1] 25987
$ kill -9 25987
$ pgrep -fa sleep
<no output>

Build

make

#### static executable using musl
./musl-make

OPTIONS

pdeathsigexec

-s/--signal : set the termination signal (default 9 (SIGKILL))

ENVIRONMENT VARIABLES

PDEATHSIGEXEC_SIGNAL : set the termination signal (default 9 (SIGKILL))