path: util-linux_2.41.3-4/sys-utils/unshare.1.adoc
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The *pidof*(1) command prints no output, because the *sleep* processes have been killed. More precisely, when the *sleep* process that has PID 1 in the namespace (i.e., the namespace's init process) was killed, this caused all other processes in the namespace to be killed. By contrast, a similar series of commands where the *--kill-child* option is not used shows that when *unshare* terminates, the processes in the PID namespace are not killed:
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