Input and output predicates

Input and output is performed in Arity/Prolog32 by a set of synchonous buffered built-in predicates. Many predicates exist in two versions: One that assumes standard in and standard out handles and one that allows you to specify the handle.

• The File input and output sub-section describes the management of file handles and files as well as two legacy (but still useful) approaches to redirecting standard input and output.
• The Term I/O and operators sub-section describes the unique way that Prolog approaches the reading and writing of Prolog terms (including clauses). The incorporation of a runtime configurable operator precedence grammar is one of the amazing features of Prolog. Arity/Prolog32 implements these features in the same way as most other Prolog implementations with some slight variations to accommodate Arity/Prolog32 data types and some added operators.
• The String, character and formatted I/O sub-section describes predicates that are more similar to the I/O functions available in libraries for more conventional languages, such as the standard libraries for 'C'.

Some related predicates, such those for listing directory contents are described in the System function predicates section.

• File Input and Output
• Term I/O and operators
• String, character and formatted I/O