This package provides a mechanism for construction Unix shell pipelines by the composition of terms representing primitive Unix processes. Each process is given a type and the compositon mechanism checks that the types of processes combined in to a pipeline match correctly

Simple usage

:- use_module(library(swipe)).

% define grep as a command taking a stream of T to a stream of T.
% Argument specified with @/1, so will be escaped properly for bash.
swipe:def(grep(Pattern), sh($T >> $T,"grep ~s",[@Pattern])).

% define sort with type stream of T to stream of T
swipe:def(sort, sh($T >> $T,"sort")).

% pipe contents from file spec =|library('swipe.pl')|= (ie using
% file search path mechanism) as type =|pl|= into grep and sort,
% with output to stdout.
:- run(library('swipe.pl')^pl :> grep(module) >> sort).

Change history

Version 0.1.0

• Changed pipe/2 to command/2.
• Added command/3 to return the inferred type of a pipeline.
• Added with_pipe_output/3 and with_pipe_input/3.
• Now depends on fileutils pack.

Version 0.2.0

• Moved with_temp_dir/2 to fileutils pack.