format
======

The function `format_x` produces output formatted according to a format string, in a style similar to the C function `sprintf`. It is an extension of the builtin function `format` as it allows the use of named lookups, e.g.:

```sql
SELECT format_x('Hello %(location)s!', '{"location": "World"}'::JSONB);
   format_x
--------------
 Hello World!
(1 row)
```

It is (TODO almost) backward compatible with the builtin `format`. Lookups are supported against composite types, `JSONB`, and `HSTORE`.

---

To build it, just do this:

    make
    make installcheck
    make install

If you encounter an error such as:

    "Makefile", line 8: Need an operator

You need to use GNU make, which may well be installed on your system as
`gmake`:

    gmake
    gmake install
    gmake installcheck

If you encounter an error such as:

    make: pg_config: Command not found

Be sure that you have `pg_config` installed and in your path. If you used a
package management system such as RPM to install PostgreSQL, be sure that the
`-devel` package is also installed. If necessary tell the build process where
to find it:

    env PG_CONFIG=/path/to/pg_config make && make installcheck && make install

And finally, if all that fails (and if you're on PostgreSQL 8.1 or lower, it
likely will), copy the entire distribution directory to the `contrib/`
subdirectory of the PostgreSQL source tree and try it there without
`pg_config`:

    env NO_PGXS=1 make && make installcheck && make install

If you encounter an error such as:

    ERROR:  must be owner of database regression

You need to run the test suite using a super user, such as the default
"postgres" super user:

    make installcheck PGUSER=postgres

Once format_x is installed, you can add it to a database. If you're running
PostgreSQL 9.1.0 or greater, it's a simple as connecting to a database as a
super user and running:

    CREATE EXTENSION format_x;

If you've upgraded your cluster to PostgreSQL 9.1 and already had format
installed, you can upgrade it to a properly packaged extension with:

    CREATE EXTENSION format_x FROM unpackaged;

For versions of PostgreSQL less than 9.1.0, you'll need to run the
installation script:

    psql -d mydb -f /path/to/pgsql/share/contrib/format_x.sql

If you want to install format_x and all of its supporting objects into a specific
schema, use the `PGOPTIONS` environment variable to specify the schema, like
so:

    PGOPTIONS=--search_path=extensions psql -d mydb -f format_x.sql

Dependencies
------------
The `format_x` extension has no dependencies other than PostgreSQL.

Copyright and License
---------------------

Copyright (c) 2016-2017 Melanie Plageman

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
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The above copyright notice and this permission notice shall be included in all
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SOFTWARE.