why cisco adopt tcl as eem script language but not perl or lua?

[lin jia]

why cisco adopt tcl as eem script language but not perl or lua?

[Joe Clarke · Accepted solution]

For historical reasons, mostly.  Tcl (because of its weight) has been in IOS since 1994.  It was used primarily for regexp support, but we also had internal scripts that leveraged it for testing.  Therefore, when we wanted to introduce on-box scripting, Tcl was an easy choice.

We now embed Python on the Nexus devices as this seems to fit better in the DC space, and it's a much more modern language.  For IOS, we will be introducing a container architecture that will allow one to run any language they want along side IOS in a LXC/KVM.

[Cory Anderson]

Hi Joe,

When do you anticipate Cisco releasing the container architecture for IOS?  Will that make its way to switches and routers?

[Joe Clarke]

IOS XE 3.17 already includes limited release availability for Open Services Containers.  I expect to see a broader announcement by the end of this calendar year.