* 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
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)
