
The Architecture of SQLite - otoolep
https://www.sqlite.org/arch.html
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78666cdc
One thing I find very interesting is the following:

>SQLite has its own private implementation of printf() (with some extensions)
in printf.c

Why?

~~~
SQLite
(1) Consistent, repeatable results across all platforms - the library will not
fail or degrade because of a platforms dodgy printf() implementation.

(2) SQLite's printf includes extensions like %q and %Q that help prevent SQL
injection attacks. These are used internally. (grep for '%q' and '%Q' in the
SQLite sources and see for yourself.)

(3) Nothing like sqlite3_mprintf() is available from standard libraries. And
yet it is a very useful and important interface.

(4) SQLite has a printf() SQL function for formatting text. I don't know of
any way to build that using a standard-library printf() implementation - you
need to have direct access to the printf() source code to make it work from
SQL.

(5) Library printf() implementations are often subject to LOCALE, which means
that if "3.14159" is render as "3,14159" (as it is for some LOCALEs) it will
break SQL syntax rules when used to construct an SQL statement.

I can probably think of other reasons, but those are the ones that come
quickly to mind.

