[anthk]

I think ed uses a tmp file.

You can try a custom sam(1) fork (it uses structural regex, google/ddg them): https://github.com/deadpixi/sam

sam -d for the classic cli mode.

[jolmg]

Yeah, ex too. I didn't know sam had a cli mode. Unfortunately, the one I have installed from[1] coredumps with the 1.1GB file after trying to write to a temp file.

[1] https://swtch.com/plan9port/

[anthk]

That's the plan9 port edition, maybe the forked one works better. Use "sam -d" for the cli version. You won't miss a lot in the end.