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SQLite Header Parse

Simple C header only library for parsing information from SQLite database headers.

Build Status

Overview

SQLite database files have quite a bit of information contained within their header. While plenty of SQLite wrapper libraries exist, I've found myself rewriting these header parsing operations several times - so I decided to put together a tiny reusable library.

The best place to find information on the official header file definition is the SQLite documentation - but I will provide some basic information below.

Usage

Include sqlite_header.h in your code, then simply create a SqliteHeaderData object and pass it along with the path to the database file to sqlite_header_parse. An error enumeration is used to communicate if the parse was successful or not. If sucesful, all header attributes can be found in the struct as members.

The table below maps the naming of header properties from the offical SQLite documentation to the names of the resulting struct.

Structure member name SQLite Description
header_str The header string: "SQLite format 3\000"
page_size_bytes The database page size in bytes. Must be a power of two between 512 and 32768 inclusive, or the value 1 representing a page size of 65536.
file_format_write_version File format write version. 1 for legacy; 2 for WAL.
file_format_read_version File format read version. 1 for legacy; 2 for WAL.
reserved_space_bytes Bytes of unused "reserved" space at the end of each page. Usually 0.
max_embedded_payload_frac Maximum embedded payload fraction. Must be 64.
min_embedded_payload_frac Minimum embedded payload fraction. Must be 32.
leaf_payload_frac Leaf payload fraction. Must be 32.
file_change_counter File change counter.
database_size_pages Size of the database file in pages. The "in-header database size".
first_freelist_trunk_page Page number of the first freelist trunk page.
total_freelist_pages Total number of freelist pages.
schema_cookie The schema cookie.
schema_format_number The schema format number. Supported schema formats are 1, 2, 3, and 4.
default_page_cache_size_bytes Default page cache size.
largest_b_tree_page_number The page number of the largest root b-tree page when in auto-vacuum or incremental-vacuum modes, or zero otherwise.
database_text_encoding The database text encoding. A value of 1 means UTF-8. A value of 2 means UTF-16le. A value of 3 means UTF-16be.
user_version The "user version" as read and set by the user_version pragma.
incremental_vaccum_mode True (non-zero) for incremental-vacuum mode. False (zero) otherwise.
application_id The "Application ID" set by PRAGMA application_id.l
version_valid_for The version-valid-for number.
sqlite_version SQLITE_VERSION_NUMBER

Building and running

Building the example can be done manually or with the provided CMakeLists.txt file.

Build & run steps

  • git clone https://github.com/patrick--/sqlite_header_parse.git
  • cd sqlite_header_parse
  • mkdir build
  • cd build
  • cmake ..
  • make
  • ./sqlite_header_parse_example