As of version 9.1.18, SWI-Prolog allows starting an application using
the command below.
swipl [option ...] [path:]name [arg ...]
This command line first processes Prolog options described in
section 2.4. Note that
most standard Prolog commandline options are not relevant. The -f
defaults to none, which implies that the user init file is
by default not loaded. If an application wishes to load the user init
file, it should load
user_app_config(init) if this file exists (see
exists_source/1).
Next, it locates path(name) using SWI-Prolog's file
search mechanism defined by absolute_file_name/3.
After loading this file it finds the last goal registered for main
using initialization/2
as described in section
2.11 - if there is no initization directive for main,
the program terminates with an error. By default, the application
terminates after the entry point terminates. The entry point may enable
the interactive Prolog REPL loop by calling
cli_enable_development_system/0.
Other forms of the initialization/2
directive are also allowed, in addition to‘main`.
All command line options after [path:]name are
accessible in the Prolog flag argv.
The optional path defaults to app. By
default, apps are searched in the directories below. See file_search_path/2
for details.
- The
app directory of the SWI-Prolog installation
- User and site configuration. On POSIX systems using the XDG file
name conventions, this is normally
/.local/share/swi-prolog/app/
and /usr/share/swi-prolog/app.
- The
app directory of a Prolog pack.
The following apps are provided by the installation
- app
- Print information on installed apps. For example, to list all available
apps, run
swipl app list
- pack
- Command line driven management of Prolog packs. This is a front-end to
the Prolog library
library(prolog_pack). For example, to
find packages related to type, use the command below.
swipl pack find type
