cat somefile | somecommand
But in DCL on VMS:
PIPE cat somefile | somecommand
That's small beer compared to the way file paths are specified. It's been too long since i last used a VMS cluster so i can't remember the syntax off hand, but it's pretty clunky.
I started my career as Fortran developer on OpenVMS for process control systems and process simulations in early 90s. OpenVMS was the choice platform for most mission critical/ life critical operations and for manufacturing process simulations then.
We ran a few pair of OpenVMS nodes in cluster to operate multimillion dollar petrochemical production facility. The share-everything clustering was cool. I don't think I have seen that since.
Actually OpenVMS helped me make transition from petrochemical to technology in 2000. A tech company was trying to find someone with prior experience in OpenVMS to support customers using their optical storage library management software on OpenVMS/Alpha. That's when I transitioned from controls to data storage.
Mainframe, not so much - imagine programming in a webform's text box where the endpoint might have gone away by the time you submit.