Manual Pages  — JEXEC

jexec – execute a command inside an existing jail

SYNOPSIS DESCRIPTION SEE ALSO HISTORY BUGS

jexec [-l] [-u username | -U username] jail [command ...]

The jexec utility executes command inside the jail identified by its jid or name. If command is not specified then the user's shell is used.

The following options are available:

-l
	Execute in a clean environment. The environment is discarded except for HOME, SHELL, TERM, USER, and anything from the login class capability database for the user.
-u username
	The user name from host environment as whom the command should run. This is the default.
-U username
	The user name from jailed environment as whom the command should run.

The jexec utility was added in FreeBSD 5.1 .

If the jail is not identified by jid there is a possible race in between the lookup of the jail and executing the command inside the jail. Giving a jid has a similar race as another process can stop the jail and start another one after the user looked up the jid.