21st Century C

Glossary

alignment

A requirement that data elements begin at certain boundaries in memory. For example, given an 8-bit alignment requirement, a struct holding a 1-bit char followed by an 8-bit int might need 7 bits of padding after the char so that the int starts on an 8-bit boundary.

ASCII

American Standard Code for Information Interchange. A standard mapping from the naïve English character set to the numbers 0–127. Tip: on many systems, man ascii will print the table of codes.

automatic allocation

For an automatically allocated variable, its space in memory is allocated by the system at the point of the variable’s declaration, then removed at the end of the given scope.

Autotools

A set of programs from the GNU that simplify automatic compilation on any system, including Autoconf, Automake, and Libtool.

Benford’s law

Leading digits in a wide range of data sets tend to have a log-like distribution: 1 has about 30% frequency, 2 about 17.5%, …, 9 about 4.5%.

Boolean

True/false. Named after George Boole, an English mathematician living in the early-to-mid 1800s.

BSD

Berkeley Software Distribution. An implementation of POSIX.

callback function

A function (A) that is sent as an input to another function (B) so that function B can call function A over the course of its operation. For example, generalized sort functions typically take as input a function to compare two elements.

call graph

A box-and-arrow diagram showing which functions call and are called by which other functions.

cetology

The study of ...