* Refactor CLI to mimic psql's meta-commands
This PR adds support for meta-commands (also known as "backslash
commands") like those in psql, Postgres's CLI. Only a few meta-commands
are currently implemented, but this was meant to demonstrate how we
could use something like `\i file.csv` to insert local files into SQL
statements.
* Meta-commands: \file and \include
The initial implementation used `\i` as a streaming file handle.
This commit changes that to `\file`, and then implements `\i` (or
`\include`) as handling multiple sql commands.
* Add meta-command "help" (\?)
This is basically a copy of the psql help output, but includes only
those options we currently support.
* Add support for \o [file], and \timing
The \o meta-command writes query output to a file.
The \timing meta-command turns on/off the timing display sent to stdout.
* Add meta-commands: \l (show databases) and \dt (show tables)
* Add meta-command: \watch [period]
* Update meta-command \connect to take database name instead of ID
* Add support for \echo, \qecho, and \warn
This commit contains an known issue in that the `-n` option will exclude
the line feed, but if the output is the terminal, the readline package
clobbers any content on the current line (i.e. anything without a line
feed). That will need to be addressed at some point.
* Add support for \w [FILE] (write query buffer to file)
* Add SchemaAPI no-op implementation
* Refactor query handler to align with /sql and /databases endpoints
We want to standardize on:
/sql
/databases/{databaseID}/sql
* Add CLI support for expanded, border, tuples_only (and pset)
* Add help text for \pset and \t
When we added a line feed to the user input, we broke the check for
"exit" (because after that change we were getting "exit\n". This commit
moves the exit check before the line feed append.
This commit moves the cli out of the `ctl` package and into its own
`cli` package. It also adds some basic tests for expected input.
Finally, it fixes a bug which was causing intentional line feeds to be
ignored, which was a problem with the BULK INSERT command.
(cherry picked from commit cf72bfa16f)
