It was surprisingly hard to find a functional, working example of copying data from a file not based on the server into a PostgreSQL database.

cat file.txt | psql -c “COPY table_name FROM STDIN” -U username database_name

And don’t forget the handy trick for disabling the password prompt in psotgres.

A few helpful search terms:

• Copy file into Postgres from local filesystem
• Copy local file into Postgres from command line
• Using psql to copy file into Postgres database from file system