Getting Started

Installing SPIRAL

SPIRAL source is available on GitHub under a non-viral BSD-style license. It builds and runs on several platforms, including Windows, Linux, macOS, and Raspberry Pi.

See the README on GitHub for more information.

GAP and the Command Line

The input language to SPIRAL is an extended version of GAP 3.

Chapters 1 and 2 of the GAP Manual cover most of what you need for SPIRAL.

Basic Syntax

In a nutshell:

  • Whitespace is ignored

  • Statements can span multiple lines and end with a semicolon (;)

  • Blocks of statements are delineated with keywords, like do/od, if/then/else/fi

  • Variable names are case sensitive and are declared implicitly by use

  • := is the assignment operator and = is the boolean equals operator

Command Line

When you start SPIRAL in a terminal window (> spiral), SPIRAL displays the spiral> command prompt that lets you enter individual statements interactively. To exit, enter quit;.

The SPIRAL command line allows edits similar to the Linux terminal window and the Windows command window.

  • CTRL+E moves the cursor to the end of the line.

  • CTRL+A moves the cursor to the beginning of the line.

  • Left and Right arrows move the cursor one character on the current line.

  • Up and Down arrows scroll back and forth through previous entries.

These have special meaning to SPIRAL:

  • CTRL+C interrupts a running statement

  • CTRL+D is equivalent to quit;

  • TAB completes a command up to a point of ambiguity. Pressing TAB again shows all choices.

  • CTRL+W shows all the field names for a record.

SPIRAL stores entries from previous sessions, so work from previous sessions is available when you start SPIRAL. Note that the history file is only saved if you exit SPIRAL with the quit; command.

Batch Mode

You can start SPIRAL in batch mode by specifying an input file at startup using the standard I/O redirection syntax, for example:

spiral < myscript.txt

SPIRAL will run the script and exit. Direct the output to a file to save it:

spiral < myscript.txt > myresults.txt


SPIRAL Options Record

opts := SpiralDefaults;

Local Configuration

Set via _spiral.g