Exess

Exess is a simple C library for reading and writing values as strings.

It provides portable locale-independent functions for converting basic number, date, time, and binary datatypes to and from strings. Conversions are lossless where possible, so, for example, a float written to a string will read back as exactly the original value on any system.

The supported datatypes, defined by the XSD specification, are explicitly compatible with many standards (like XML, RDF, and ISO 8601), and incidentally or partially compatible with many others (like C and JSON).

The library is straightforward to use and has minimal requirements. It doesn't depend on an allocator, the current locale, or any other shared mutable state, making it safe to use in almost any context.

Supported Datatypes

Most of the XSD datatypes are implemented, omitting some XML-specific and recurring Gregorian calendar datatypes. Support for reading and writing is provided for:

• boolean, like "false", "true", "0", or "1".

• decimal, like "1.234" (stored as double).

• float and double, like "4.2E1" or "4.2e1".

• The unbounded integer types integer, nonPositiveInteger, negativeInteger, nonNegativeInteger, and nonPositiveInteger (stored as int64_t or uint64_t).

• The fixed-size integer types long, int, short, byte, unsignedLong, unsignedInt, unsignedShort, and unsignedByte.

• duration, like "P1Y6M".

• dateTime, like "2001-01-30T14:30:45".

• time, like "12:30:00.00".

• date, like "2001-12-31".

• hexBinary, like "EC5355".

• base64Binary, like "Zm9vYmFy".

Dependencies

None, except the C standard library. More precisely, exess uses only the following functions from the standard library:

• ceil
• ldexp
• llrint
• llrintf
• memcmp
• memcpy
• memset
• nextafter
• strcmp
• strncmp
• trunc
• truncf

Documentation

• Installation instructions
• Manual
  • Installed as man exess and related pages
  • HTML
  • Single-page HTML
  • EPub

-- David Robillard d@drobilla.net