Hello, I've been biten by psql's \copy lack of variable expansion, in a limited-access docker-inside-VM context where COPY is not a viable option and hardwired names are not desirable. The attached patch allows \copy to use variable's values in place of table and file names:
```psql \set table 'some table' \set input 'some file name.csv' \copy :"table" from :'input' with (format csv) ``` -- Fabien.
