mirror of
https://git.code.sf.net/p/quake/quakeforge
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2080 lines
38 KiB
Text
2080 lines
38 KiB
Text
#LyX 1.3 created this file. For more info see http://www.lyx.org/
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\lyxformat 221
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\textclass article
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\begin_preamble
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\usepackage{ae,aecompl}
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\end_preamble
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\language english
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\inputencoding auto
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\fontscheme default
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\graphics default
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\paperfontsize default
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\spacing single
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\papersize Default
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\paperpackage a4
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\use_geometry 0
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\use_amsmath 0
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\use_natbib 0
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\use_numerical_citations 0
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\paperorientation portrait
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\secnumdepth 3
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\tocdepth 3
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\paragraph_separation indent
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\defskip medskip
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\quotes_language english
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\quotes_times 2
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\papercolumns 1
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\papersides 1
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\paperpagestyle default
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\layout Title
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\begin_inset Graphics
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filename gib_head.eps
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\end_inset
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\newline
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\family sans
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\series bold
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The GIB Scripting Language
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\layout Author
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Brian Koropoff
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\layout Standard
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\pagebreak_top \pagebreak_bottom
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\begin_inset LatexCommand \tableofcontents{}
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\end_inset
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\layout Section
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Introduction
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\layout Subsection
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Purpose and Applications
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\layout Standard
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GIB
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\begin_inset Foot
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collapsed false
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\layout Standard
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\noun on
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GIB
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\noun default
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stands for
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\begin_inset Quotes eld
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\end_inset
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\series bold
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G
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\series default
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IB
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\series bold
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I
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\series default
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sn't
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\series bold
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\noun on
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B
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\series default
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ash
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\noun default
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.
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\begin_inset Quotes erd
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\end_inset
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\noun on
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Bash
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\noun default
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is the
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\noun on
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GNU
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\noun default
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implementation of the UNIX shell, with which GIB shares many similarities.
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\end_inset
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is a scripting language first introduced in
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\noun on
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QuakeForge
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\noun default
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0.5.2, although it existed in several (less successful) incarnations in the
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CVS development tree before finding its way into a release.
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I created it out of frustration at the limited abilities of the standard
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\noun on
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Quake
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\noun default
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console for client-side scripting.
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The language that resulted now has applications ranging from glorified
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aliases to server-side chat bots and map voting scripts.
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\layout Subsection
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Features
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\layout Standard
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Some of GIB's more noteworthy features include:
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\layout Itemize
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Full branching and looping support, including
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\family typewriter
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if-else
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\family default
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,
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\family typewriter
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while
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\family default
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, and
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\family typewriter
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for
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\family default
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structures.
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\layout Itemize
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Local and global variables, arrays, and hashes (all rolled into one, see
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Section
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\begin_inset LatexCommand \vref{sec:variables}
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\end_inset
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for details) as well as access to standard console variables.
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\layout Itemize
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A full-featured math evaluator supporting correct order of operations and
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most arithmetic, logical, and bitwise operators.
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\layout Itemize
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Functions that can be passed any number of arguments and return any number
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of values to the caller.
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\layout Itemize
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File and directory access.
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\layout Itemize
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String manipulation functions, including regular expressions.
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\layout Itemize
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\begin_inset Quotes eld
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\end_inset
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Cooperative
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\begin_inset Quotes erd
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\end_inset
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threading.
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\layout Itemize
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An event system, wherein GIB functions can be run when a certain event occurs,
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such as a chat message being received or the player's health changing.
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\layout Itemize
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Integration with the console.
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Console commands can be used from GIB, and GIB functions can be
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\begin_inset Quotes eld
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\end_inset
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exported
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\begin_inset Quotes erd
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\end_inset
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to the console as normal commands.
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\layout Section
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\pagebreak_top
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Language Basics
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\layout Subsection
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Command Syntax
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\layout Standard
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GIB follows the same syntax for basic commands as the standard Quake console:
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the command, followed by any number of spaces and a space-separated list
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of arguments.
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Consider the following console command, which is also a legitimate GIB
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command:
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\layout LyX-Code
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echo Hello world!
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\layout Standard
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Each command is usually placed on a separate line, but a semicolon (
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\family typewriter
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;
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\family default
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) may be used to separate multiple commands on a single line:
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\layout LyX-Code
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echo This is a command; echo ...and so is this!
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\layout Subsection
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Enclosing Arguments
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\layout Standard
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A normal argument is considered to end at the first
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\begin_inset Quotes eld
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\end_inset
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whitespace
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\begin_inset Quotes erd
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\end_inset
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character or comma (see Section
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\begin_inset LatexCommand \ref{sub:concat}
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\end_inset
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) encountered.
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Arguments may be optionally enclosed in certain characters to either define
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their boundaries or specify special processing to be done before the command
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is run.
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\layout Subsubsection
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Double Quotes
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\layout Standard
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An argument may be enclosed in double quotes (
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\family typewriter
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"
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\family default
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and
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\family typewriter
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"
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\family default
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, never smart quotes!), in which case the argument consists of all characters
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within the quotes, including any spaces.
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For example:
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\layout LyX-Code
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print "Hello, world!"
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\layout Standard
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\added_space_bottom bigskip
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In addition, special processing is done to arguments in quotes to allow
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the inclusion of characters that can't normally be typed.
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If a character is preceded by a backslash (
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\family typewriter
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\backslash
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\family default
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), the backslash and the character will be replaced with a special character.
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This is referred to as
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\begin_inset Quotes eld
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\end_inset
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escaping.
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\begin_inset Quotes erd
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\end_inset
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Figure
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\begin_inset LatexCommand \vref{cap:escapes}
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\end_inset
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lists possible characters and their replacements.
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\layout Standard
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\begin_inset Float figure
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wide false
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collapsed false
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\layout Standard
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\align center
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\begin_inset Tabular
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<lyxtabular version="3" rows="6" columns="2">
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<features>
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<column alignment="center" valignment="top" leftline="true" width="0in">
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<column alignment="left" valignment="top" leftline="true" rightline="true" width="0in">
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<row topline="true" bottomline="true">
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<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
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\begin_inset Text
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\layout Standard
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Character
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\end_inset
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</cell>
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<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
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\begin_inset Text
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\layout Standard
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Replacement
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\end_inset
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</cell>
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</row>
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<row topline="true">
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<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
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\begin_inset Text
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\layout Standard
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\family typewriter
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n
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\end_inset
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</cell>
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<cell alignment="left" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
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\begin_inset Text
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\layout Standard
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Newline
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\end_inset
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</cell>
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</row>
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<row topline="true">
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<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
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\begin_inset Text
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\layout Standard
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\family typewriter
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t
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\end_inset
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</cell>
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<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
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\begin_inset Text
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\layout Standard
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Tab
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\end_inset
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</cell>
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</row>
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<row topline="true">
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<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
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\begin_inset Text
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\layout Standard
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\family typewriter
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r
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\end_inset
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</cell>
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<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
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\begin_inset Text
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\layout Standard
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Carriage return
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\end_inset
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</cell>
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</row>
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<row topline="true">
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<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
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\begin_inset Text
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\layout Standard
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\family typewriter
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"
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\end_inset
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</cell>
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<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
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\begin_inset Text
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\layout Standard
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Double quote (does not end argument)
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\end_inset
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</cell>
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</row>
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<row topline="true" bottomline="true">
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<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
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\begin_inset Text
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\layout Standard
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\family typewriter
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\backslash
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\end_inset
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</cell>
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<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
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\begin_inset Text
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\layout Standard
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Backslash (does not escape next character)
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\end_inset
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</cell>
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</row>
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</lyxtabular>
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\end_inset
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\layout Caption
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Escape characters
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\begin_inset LatexCommand \label{cap:escapes}
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\end_inset
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\end_inset
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\layout Standard
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\added_space_top bigskip
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The preceding code example could be rewritten to include a newline character
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so that printing will continue on the next line:
|
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\layout LyX-Code
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print "Hello, world!
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\backslash
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n"
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\layout Standard
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\added_space_bottom bigskip
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Besides a single character, a backslash can be followed by three digits
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forming a decimal number between 0 and 255, in which case the backslash
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and all digits are replaced by the character with the value of the number.
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\layout Standard
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\line_top \line_bottom \align left
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\series bold
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\color red
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Warning
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\color default
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:
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\series default
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\emph on
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Attempting to send any string with the character of decimal value 255 over
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the network will result in a malformed packet and an immediate loss of
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connection.
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Do not use
|
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\family typewriter
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"
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\backslash
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255"
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\family default
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in any chat message, info string, or any other text sent between the client
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and server.
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\layout Standard
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\added_space_top bigskip
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Double quotes must be evenly matched, or a parse error will be issued when
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GIB attempts to execute the script.
|
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\layout Subsubsection
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Parentheses
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\layout Standard
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An argument may be enclosed within parentheses, in which case the argument
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will be evaluated as a mathematical expression and will be replaced with
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the result of that expression.
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Consider the following code:
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\layout LyX-Code
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echo (1/(1+1))
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\layout Standard
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This will result in
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\begin_inset Quotes eld
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\end_inset
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0.5
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\begin_inset Quotes erd
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\end_inset
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being printed.
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For a detailed explanation of the capabilities of the math evaluator, please
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see Section .
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As with double quotes, parentheses must be evenly matched or a parse error
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will be issued.
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\layout Subsubsection
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Curly Braces
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\layout Standard
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Arguments within curly braces (
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\family typewriter
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{
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\family default
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and
|
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\family typewriter
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}
|
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\family default
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) are treated as
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\emph on
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program blocks
|
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\emph default
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, or groups of GIB commands.
|
|
To facilitate readable formatting of code, line breaks are allowed within
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curly braces.
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|
Curly braces should only be used where GIB code is appropriate, such as
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in a loop or function definitions.
|
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Arguments in curly braces
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\emph on
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may
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\emph default
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be used for any purpose, but this comes with two drawbacks:
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\layout Enumerate
|
|
|
|
Arguments in curly braces are considered code and will be held to those
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standards.
|
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Parse errors within curly braces will prevent execution of your script,
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even if the argument is not used where a program block is requested.
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\layout Enumerate
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|
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The GIB parser will convert code in curly braces to an internal representation,
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which is a waste of time and resources if the argument is never used as
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a program block.
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\layout Standard
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|
|
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\begin_inset Float figure
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wide false
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collapsed false
|
|
|
|
\layout LyX-Code
|
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\line_top \line_bottom
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|
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\begin_inset Include \verbatiminput{curly.gib}
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preview false
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\end_inset
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|
|
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\layout Caption
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|
|
|
Example uses of curly braces
|
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\begin_inset LatexCommand \label{cap:curly}
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\end_inset
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\end_inset
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|
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\layout Standard
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|
Figure
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\begin_inset LatexCommand \vref{cap:curly}
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|
\end_inset
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|
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|
uses features that will be discussed later, but it demonstrates several
|
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of the intended uses of curly braces.
|
|
\layout Subsection
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|
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|
Concatenation
|
|
\begin_inset LatexCommand \label{sub:concat}
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|
|
|
\end_inset
|
|
|
|
|
|
\layout Standard
|
|
|
|
Concatenation refers to joining one argument onto the end of another.
|
|
This is useful when you want to combine different arguments into one, such
|
|
as a double-quoted argument and a math expression.
|
|
To do this, simply place a single comma (
|
|
\family typewriter
|
|
,
|
|
\family default
|
|
) anywhere between arguments.
|
|
Example:
|
|
\layout LyX-Code
|
|
|
|
print "20 divided by 4 is ", (20/4), "
|
|
\backslash
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|
n"
|
|
\layout Standard
|
|
|
|
Concatenation will not work with curly-brace-enclosed arguments.
|
|
In addition, it will not work or simply be ignored on instances of variable
|
|
expansion, which will be discussed in Section
|
|
\begin_inset LatexCommand \ref{sec:variables}
|
|
|
|
\end_inset
|
|
|
|
.
|
|
\layout Subsection
|
|
|
|
Comments
|
|
\layout Standard
|
|
|
|
GIB uses the same format for comments as the console.
|
|
Any text between two forward slashes (
|
|
\family typewriter
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|
//
|
|
\family default
|
|
) and the end of the current line will be discarded when the script is parsed.
|
|
To use two forward slashes without starting a comment, enclose the argument
|
|
in double quotes.
|
|
Example:
|
|
\layout LyX-Code
|
|
|
|
echo "Hello" // This is a comment
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|
\layout LyX-Code
|
|
|
|
echo "// This is not a comment"
|
|
\layout Standard
|
|
|
|
Proper use of comments in your scripts will make them easier to read and
|
|
understand.
|
|
\layout Section
|
|
\pagebreak_top
|
|
Variables
|
|
\begin_inset LatexCommand \label{sec:variables}
|
|
|
|
\end_inset
|
|
|
|
|
|
\layout Subsection
|
|
|
|
Types and Concepts
|
|
\layout Standard
|
|
|
|
GIB offers several powerful forms of variables:
|
|
\layout Description
|
|
|
|
Console\SpecialChar ~
|
|
variables hold a character string and can also be accessed from the
|
|
|
|
\noun on
|
|
QuakeForge
|
|
\noun default
|
|
console.
|
|
\layout Description
|
|
|
|
Standard\SpecialChar ~
|
|
variables hold a character string.
|
|
\layout Description
|
|
|
|
Arrays hold a numbered list of character strings, each referred to as an
|
|
|
|
\emph on
|
|
element
|
|
\emph default
|
|
.
|
|
\layout Description
|
|
|
|
Hashes hold a list of arrays, each referenced by a unique name called a
|
|
|
|
\emph on
|
|
key
|
|
\emph default
|
|
.
|
|
\layout Standard
|
|
|
|
Unlike many other languages, these different types of variables are not
|
|
defined separately.
|
|
Rather, all non-console GIB variables are a hash/array hybrid.
|
|
Every variable is an array, and every element in that array also can be
|
|
a hash.
|
|
This may sound confusing at first, but it is actually quite intuitive and
|
|
powerful.
|
|
\layout Standard
|
|
|
|
Variables in GIB can be used in three different ways:
|
|
\layout Itemize
|
|
|
|
|
|
\series bold
|
|
Assignment
|
|
\series default
|
|
|
|
\newline
|
|
A value (character string) is stored in the variable.
|
|
\layout Itemize
|
|
|
|
|
|
\series bold
|
|
Embedding
|
|
\series default
|
|
|
|
\newline
|
|
The value of a variable is placed somewhere within an argument.
|
|
\layout Itemize
|
|
|
|
|
|
\series bold
|
|
Expansion
|
|
\series default
|
|
|
|
\newline
|
|
A new argument is created in the command for each element of an array or
|
|
each key in a hash.
|
|
\layout Standard
|
|
|
|
Note that console variables cannot be expanded, as they may only hold one
|
|
value.
|
|
\layout Subsection
|
|
|
|
Console Variables
|
|
\layout Standard
|
|
|
|
Console variables are the normal settings used at the
|
|
\noun on
|
|
QuakeForge
|
|
\noun default
|
|
console, such as
|
|
\family typewriter
|
|
in_mouse_amp
|
|
\family default
|
|
,
|
|
\family typewriter
|
|
fov
|
|
\family default
|
|
, etc.
|
|
These are the simplest variables available to GIB.
|
|
\layout Subsubsection
|
|
|
|
Assigning to Console Variables
|
|
\layout Standard
|
|
|
|
To assign to a console variable from GIB, simply use the
|
|
\family typewriter
|
|
set
|
|
\family default
|
|
console command with the name of the console variable as the first argument
|
|
and the value to assign as the second.
|
|
Example:
|
|
\layout LyX-Code
|
|
|
|
set fov 90.0
|
|
\layout Subsubsection
|
|
|
|
Embedding Console Variables
|
|
\layout Standard
|
|
|
|
To embed the value of a console variable in an argument, include the name
|
|
of the variable preceded by a dollar sign (
|
|
\family typewriter
|
|
$
|
|
\family default
|
|
).
|
|
This only works within normal arguments or parenthesis-enclosed arguments.
|
|
Examples:
|
|
\layout LyX-Code
|
|
|
|
echo The current field of vision is $fov degrees.
|
|
\layout LyX-Code
|
|
|
|
echo Zoom factor: (90.0/$fov)
|
|
\layout Standard
|
|
|
|
The name of the variable is considered to span from after the dollar sign
|
|
to before the first non-alphanumeric, non-underline character.
|
|
Example:
|
|
\layout LyX-Code
|
|
|
|
echo Your mouse sensitivity is currently $in_mouse_amp.
|
|
\layout Standard
|
|
|
|
The command above will result in the current mouse sensitivity being printed,
|
|
as
|
|
\family typewriter
|
|
in_mouse_amp
|
|
\family default
|
|
consists of only letters and underlines.
|
|
The period at the end of the sentence is not a number, letter, or underline,
|
|
and thus is not counted as part of the variable name, even though it is
|
|
part of the last argument.
|
|
\layout Standard
|
|
|
|
To use variables with unusual names, or to separate the name of a variable
|
|
from surrounding alphanumeric characters, enclose the name of the variable
|
|
in curly braces.
|
|
Examples:
|
|
\layout LyX-Code
|
|
|
|
echo /
|
|
\backslash
|
|
/
|
|
\backslash
|
|
/
|
|
\backslash
|
|
has the value ${/
|
|
\backslash
|
|
/
|
|
\backslash
|
|
/
|
|
\backslash
|
|
}.
|
|
\layout LyX-Code
|
|
|
|
echo Fieldofvisionis${fov}degrees.Wheredidmyspacebargo?
|
|
\layout Standard
|
|
|
|
Variables that do not exist are considered to contain an empty string.
|
|
\layout Subsection
|
|
|
|
Standard Variables
|
|
\begin_inset LatexCommand \label{sub:stdvars}
|
|
|
|
\end_inset
|
|
|
|
|
|
\layout Standard
|
|
|
|
As noted before, all non-console GIB variables are also arrays.
|
|
However, their array properties can be ignored for simplicity, in which
|
|
case the first element of an array is used for storing and retrieving a
|
|
value.
|
|
\layout Subsubsection
|
|
|
|
Assigning to Standard Variables
|
|
\begin_inset LatexCommand \label{sub:assignstandard}
|
|
|
|
\end_inset
|
|
|
|
|
|
\layout Standard
|
|
|
|
To assign to a standard variable, begin a command with the name of the variable,
|
|
followed by at least one space and an equals (
|
|
\family typewriter
|
|
=
|
|
\family default
|
|
) sign, followed by any non-program-block argument.
|
|
Example:
|
|
\layout LyX-Code
|
|
|
|
foo = "bar"
|
|
\layout Standard
|
|
|
|
The above example will store
|
|
\begin_inset Quotes eld
|
|
\end_inset
|
|
|
|
bar
|
|
\begin_inset Quotes erd
|
|
\end_inset
|
|
|
|
in the variable
|
|
\family typewriter
|
|
foo
|
|
\family default
|
|
.
|
|
\layout Subsubsection
|
|
|
|
Embedding Standard Variables
|
|
\layout Standard
|
|
|
|
Standard variables are embedded the same way as console variables: a dollar
|
|
sign, followed by the name of the variable or the name of the variable
|
|
in curly braces.
|
|
To display the stored value in the example in Section
|
|
\begin_inset LatexCommand \ref{sub:assignstandard}
|
|
|
|
\end_inset
|
|
|
|
, simply do:
|
|
\layout LyX-Code
|
|
|
|
echo $foo
|
|
\layout Subsection
|
|
|
|
Arrays
|
|
\layout Standard
|
|
|
|
Arrays are simply an extension of standard variables.
|
|
They are divided into numbered elements beginning at 0.
|
|
\layout Subsubsection
|
|
|
|
Assigning to Arrays
|
|
\layout Standard
|
|
|
|
Assignment to arrays is the same as assignment to standard variables, except
|
|
that you specify the element of the array to which you wish to assign.
|
|
In fact, all standard variables
|
|
\emph on
|
|
are
|
|
\emph default
|
|
arrays.
|
|
When the element is not specified, it defaults to element 0.
|
|
All examples in section
|
|
\begin_inset LatexCommand \ref{sub:stdvars}
|
|
|
|
\end_inset
|
|
|
|
use element 0 of an array via this default behavior.
|
|
To specify a specific element, follow the name of the variable by the element
|
|
number enclosed in brackets (
|
|
\family typewriter
|
|
[
|
|
\family default
|
|
and
|
|
\family typewriter
|
|
]
|
|
\family default
|
|
).
|
|
Example:
|
|
\layout LyX-Code
|
|
|
|
foo[2] = "Hello!"
|
|
\layout Standard
|
|
|
|
It's possible--and useful--to assign to several elements of an array at
|
|
the same time.
|
|
To do this, simply include more than one argument after the equals sign.
|
|
All elements starting at the specified number will be assigned with their
|
|
respective argument.
|
|
Example:
|
|
\layout LyX-Code
|
|
|
|
foo[0] = "one" "two"
|
|
\layout Standard
|
|
|
|
This will assign
|
|
\begin_inset Quotes eld
|
|
\end_inset
|
|
|
|
one
|
|
\begin_inset Quotes erd
|
|
\end_inset
|
|
|
|
to the element 0 of
|
|
\family typewriter
|
|
foo
|
|
\family default
|
|
and
|
|
\begin_inset Quotes eld
|
|
\end_inset
|
|
|
|
two
|
|
\begin_inset Quotes erd
|
|
\end_inset
|
|
|
|
to element 1.
|
|
If you specify no arguments after the equals sign, all elements beginning
|
|
at the specified number are simply removed.
|
|
If this is element 0, the variable becomes a zero-size array, which is
|
|
important in embedding and expansion.
|
|
\layout Subsubsection
|
|
|
|
Embedding Arrays
|
|
\layout Standard
|
|
|
|
As with assignment, you need only specify the element number in brackets
|
|
after the name of a variable to use that specific element.
|
|
Example:
|
|
\layout LyX-Code
|
|
|
|
echo $foo[2]
|
|
\layout Standard
|
|
|
|
If you wish to enclose the name of the variable in curly braces, the brackets
|
|
and element number must fall inside the braces:
|
|
\layout LyX-Code
|
|
|
|
echo ${foo[2]}
|
|
\layout Standard
|
|
|
|
Instead of a dollar sign, you may use a number symbol (
|
|
\family typewriter
|
|
#
|
|
\family default
|
|
).
|
|
In this case, the size of the array will be embedded in the argument rather
|
|
than its value.
|
|
Variables that have never been used are considered to have a size of zero.
|
|
If you specify an element, the size of the array minus the specified number
|
|
will be used.
|
|
Example:
|
|
\layout LyX-Code
|
|
|
|
foo = "one" "two" "three"
|
|
\layout LyX-Code
|
|
|
|
echo #foo // Prints: 3
|
|
\layout LyX-Code
|
|
|
|
echo #foo[1] // Prints: 2
|
|
\layout Subsubsection
|
|
|
|
Expanding Arrays
|
|
\layout Standard
|
|
|
|
A very useful feature of arrays is the ability to expand them into multiple
|
|
arguments.
|
|
If a normal argument begins with an at symbol (
|
|
\family typewriter
|
|
@
|
|
\family default
|
|
), the rest of the argument will be treated as the name of an array.
|
|
The argument will be removed and replaced by a single argument for each
|
|
element of the array.
|
|
Consider the following program:
|
|
\layout LyX-Code
|
|
|
|
array = one two three
|
|
\layout LyX-Code
|
|
|
|
echo @array
|
|
\layout Standard
|
|
|
|
This prints the exact same thing as:
|
|
\layout LyX-Code
|
|
|
|
echo one two three
|
|
\layout Standard
|
|
|
|
It's possible to specify a range of elements to use instead of the entire
|
|
array.
|
|
To do this, follow the name of the array with an opening bracket, the number
|
|
of the first element to use, a colon (:), one plus the number of the last
|
|
element to use, and a closing bracket.
|
|
Example:
|
|
\layout LyX-Code
|
|
|
|
array = one two three four
|
|
\layout LyX-Code
|
|
|
|
echo @array[1:3] // Prints: two three
|
|
\layout LyX-Code
|
|
|
|
\layout Standard
|
|
\line_top \line_bottom
|
|
|
|
\series bold
|
|
Note
|
|
\series default
|
|
:
|
|
\emph on
|
|
To understand why you add one to the second number, envision each element
|
|
of the array as a different pile of groceries on a store checkout belt.
|
|
Between each pile sits a plastic separator.
|
|
The numbers in the brackets represent the numbers of the separators.
|
|
To specify the second and third piles of groceries, you would pick all
|
|
the piles between the first separator and the third separator.
|
|
If bad analogies don't suit you, simply remember to specify one more than
|
|
the last element that you want.
|
|
\layout Standard
|
|
|
|
Negative numbers count backward from the end of the array.
|
|
For instance, using -1 for the second number will include everything except
|
|
the very last element of the array.
|
|
To specify the very end of the array, omit the second number.
|
|
Examples:
|
|
\layout LyX-Code
|
|
|
|
array = one two three four
|
|
\layout LyX-Code
|
|
|
|
echo @array[1:-1] // Prints: two three
|
|
\layout LyX-Code
|
|
|
|
echo @array[2:] // Prints: three four
|
|
\layout LyX-Code
|
|
|
|
echo @array[-1:] // Prints: four
|
|
\layout Standard
|
|
|
|
If the selected range does not make sense (i.e.
|
|
the starting element comes after the ending element), or begins past the
|
|
end of the array, no arguments will be added.
|
|
If the range begins within the array but extends beyond its size, it will
|
|
be clipped to the end of the array.
|
|
\layout Subsection
|
|
|
|
Hashes
|
|
\layout Standard
|
|
|
|
Every element in a GIB array is capable of containing a hash.
|
|
A hash is an unordered list of names, called
|
|
\emph on
|
|
keys
|
|
\emph default
|
|
, that can be used to access more arrays.
|
|
Another way to think about it is that each element of an array can have
|
|
its own set of variables.
|
|
\layout Subsubsection
|
|
|
|
Assigning to Hashes
|
|
\layout Standard
|
|
|
|
Assignment to a hash is very similar to normal assignment, except that you
|
|
must specify an additional name (called the key) and optional element number.
|
|
The element that contains the hash is called the
|
|
\emph on
|
|
stem
|
|
\emph default
|
|
, and the array stored in the hash is called the
|
|
\emph on
|
|
leaf
|
|
\emph default
|
|
.
|
|
The stem and leaf are separated by a single period.
|
|
Examples:
|
|
\layout LyX-Code
|
|
|
|
foo.bar = "Hello"
|
|
\layout LyX-Code
|
|
|
|
foo[2].bar = "World"
|
|
\layout LyX-Code
|
|
|
|
foo[3].bar[2] = "!!"
|
|
\layout LyX-Code
|
|
|
|
foo.bar.baz = "There is no limit to the depth of hashes"
|
|
\layout Standard
|
|
|
|
As the last example shows, the elements of the arrays stored in a hash can
|
|
have their
|
|
\emph on
|
|
own
|
|
\emph default
|
|
hashes.
|
|
The depth of GIB variables is limited only by system memory.
|
|
\layout Subsubsection
|
|
|
|
Embedding Hashes
|
|
\layout Standard
|
|
|
|
As with assignment, embedding hashes uses the same format as embedding standard
|
|
variables.
|
|
However, you
|
|
\emph on
|
|
must
|
|
\emph default
|
|
use curly braces or the periods between stems and leaves will not be treated
|
|
as part of the variable.
|
|
Examples:
|
|
\layout LyX-Code
|
|
|
|
echo ${foo.bar}
|
|
\layout LyX-Code
|
|
|
|
echo ${foo[2].bar}
|
|
\layout LyX-Code
|
|
|
|
echo ${foo[3].bar[2]}
|
|
\layout LyX-Code
|
|
|
|
echo ${foo.bar.baz}
|
|
\layout Subsubsection
|
|
|
|
Expanding Hashes
|
|
\layout Standard
|
|
|
|
If an array element contains a hash, it's possible to acquire a list of
|
|
all the keys it contains.
|
|
If a normal argument begins with a percent symbol (
|
|
\family typewriter
|
|
%
|
|
\family default
|
|
), the rest of the argument will be treated as the name of a variable and
|
|
optional element number.
|
|
The argument will be removed, and one argument will be added in its place
|
|
for each key in the hash.
|
|
Example:
|
|
\layout LyX-Code
|
|
|
|
foo.one = "a"
|
|
\layout LyX-Code
|
|
|
|
foo.two = "b"
|
|
\layout LyX-Code
|
|
|
|
foo.three = "c"
|
|
\layout LyX-Code
|
|
|
|
echo %foo // Prints in any order: one two three
|
|
\layout Standard
|
|
|
|
If the hash is unused or contains no keys, no arguments will be added.
|
|
Note that the order of keys in the resulting list is unpredictable.
|
|
\layout Subsection
|
|
|
|
Dynamic Variables
|
|
\layout Standard
|
|
|
|
Many of the features of variables would be absolutely useless without the
|
|
ability to assign, embed, or expand variables differently depending on
|
|
circumstances when the program is run.
|
|
For instance, arrays would not be very flexible if you couldn't calculate
|
|
the element number you wish to access while the program is running.
|
|
Luckily, GIB allows you to use values of other variables to construct the
|
|
name a variable before accessing it.
|
|
\layout Subsubsection
|
|
|
|
Assigning Dynamically
|
|
\layout Standard
|
|
|
|
To assign dynamically, simply embed other variables as you would in any
|
|
other argument.
|
|
For instance, you could assign to an element of an array as follows:
|
|
\layout LyX-Code
|
|
|
|
number = 2
|
|
\layout LyX-Code
|
|
|
|
foo[$number] = "bar"
|
|
\layout Standard
|
|
|
|
Variable leaves can be assigned to in the same way:
|
|
\layout LyX-Code
|
|
|
|
leaf = "bar"
|
|
\layout LyX-Code
|
|
|
|
foo.$leaf.message = "This variable was assigned to dynamically."
|
|
\layout Standard
|
|
|
|
Deciding element numbers or leaves while the script is running is the chief
|
|
use of this ability, but you can dynamically construct a variable name
|
|
any way you wish:
|
|
\layout LyX-Code
|
|
|
|
array = "in" "mouse" "amp"
|
|
\layout LyX-Code
|
|
|
|
echo Setting sensitivity to 10...
|
|
\layout LyX-Code
|
|
|
|
set ${array[0]}_${array[1]}_${array[2]} 10
|
|
\layout Standard
|
|
|
|
This may prove useful under certain circumstances, even though the example
|
|
given isn't one of them.
|
|
\layout Subsubsection
|
|
|
|
Embedding Dynamically
|
|
\layout Standard
|
|
|
|
Embedding dynamically follows a similar pattern.
|
|
Within the name of an embedded variable you may embed other variables.
|
|
Example:
|
|
\layout LyX-Code
|
|
|
|
number = 3
|
|
\layout LyX-Code
|
|
|
|
foo[$number] = "bar"
|
|
\layout LyX-Code
|
|
|
|
echo Element $number of foo is equal to $foo[$number]
|
|
\layout Standard
|
|
|
|
This works for leaves as well:
|
|
\layout LyX-Code
|
|
|
|
leaf = "bar"
|
|
\layout LyX-Code
|
|
|
|
foo.$leaf = "Hello"
|
|
\layout LyX-Code
|
|
|
|
echo ${foo.$leaf} // Prints: Hello
|
|
\layout Standard
|
|
|
|
Remember that in most circumstances, you must surround the entire variable
|
|
name with braces.
|
|
The only case where you don't have to is when embedding a variable as an
|
|
element number, as in the first example.
|
|
\layout Subsubsection
|
|
|
|
Expanding Dynamically
|
|
\layout Standard
|
|
|
|
Dynamic expansion is as simple as dynamic assignment.
|
|
You can embed variables in an argument beginning with @ or % as you would
|
|
with any other argument.
|
|
Example:
|
|
\layout LyX-Code
|
|
|
|
array = one two three four
|
|
\layout LyX-Code
|
|
|
|
start = 1
|
|
\layout LyX-Code
|
|
|
|
end = 3
|
|
\layout LyX-Code
|
|
|
|
echo @array[$start:$end] // Prints: two three
|
|
\layout Subsection
|
|
|
|
Variable Scope
|
|
\layout Comment
|
|
|
|
FIXME: add this section!
|
|
\layout Subsubsection
|
|
|
|
Locals
|
|
\layout Subsubsection
|
|
|
|
Globals
|
|
\layout Subsubsection
|
|
|
|
Domains
|
|
\layout Section
|
|
\pagebreak_top
|
|
Flow Control
|
|
\layout Standard
|
|
|
|
Flow control refers to controlling the order in which commands are executed
|
|
-- or if they are executed at all -- in your GIB script.
|
|
GIB currently offers two ways to control program flow:
|
|
\layout Description
|
|
|
|
Conditionals execute a command or group of commands if a certain condition
|
|
is met
|
|
\layout Description
|
|
|
|
Loops execute a command or group of commands multiple times while a certain
|
|
condition is met.
|
|
\layout Subsection
|
|
|
|
Conditionals
|
|
\layout Subsubsection
|
|
|
|
|
|
\family typewriter
|
|
if
|
|
\family default
|
|
and
|
|
\family typewriter
|
|
ifnot
|
|
\layout Standard
|
|
|
|
The
|
|
\family typewriter
|
|
if
|
|
\family default
|
|
structure will execute a group of commands when a condition is
|
|
\begin_inset Quotes eld
|
|
\end_inset
|
|
|
|
true.
|
|
\begin_inset Quotes erd
|
|
\end_inset
|
|
|
|
An optional
|
|
\family typewriter
|
|
else
|
|
\family default
|
|
structure may follow, which contains a group of commands to be executed
|
|
if the condition is
|
|
\begin_inset Quotes eld
|
|
\end_inset
|
|
|
|
false
|
|
\begin_inset Quotes erd
|
|
\end_inset
|
|
|
|
.
|
|
When
|
|
\family typewriter
|
|
ifnot
|
|
\family default
|
|
is used, the condition is reversed.
|
|
The syntax for
|
|
\family typewriter
|
|
if
|
|
\family default
|
|
and
|
|
\family typewriter
|
|
ifnot
|
|
\family default
|
|
is as follows:
|
|
\layout LyX-Code
|
|
|
|
|
|
\family sans
|
|
if
|
|
\family default
|
|
condition block1 [
|
|
\family sans
|
|
else
|
|
\family default
|
|
block2]
|
|
\layout Standard
|
|
|
|
Explanations of what each part means follow:
|
|
\layout Description
|
|
|
|
condition may be any type of argument that is not a program block.
|
|
Its value will be treated as a number; 0 will be deemed
|
|
\begin_inset Quotes eld
|
|
\end_inset
|
|
|
|
false
|
|
\begin_inset Quotes erd
|
|
\end_inset
|
|
|
|
and all other numbers will be deemed
|
|
\begin_inset Quotes eld
|
|
\end_inset
|
|
|
|
true.
|
|
\begin_inset Quotes erd
|
|
\end_inset
|
|
|
|
If the value does not appear to be a number, it will be considered false.
|
|
When
|
|
\family typewriter
|
|
ifnot
|
|
\family default
|
|
is used instead of
|
|
\family typewriter
|
|
if
|
|
\family default
|
|
, true and false are reversed.
|
|
\layout Description
|
|
|
|
block1 must be a program block argument.
|
|
If
|
|
\family typewriter
|
|
condition
|
|
\family default
|
|
was considered to be true, the commands in the block will be executed.
|
|
\layout Description
|
|
|
|
else may optionally follow
|
|
\family typewriter
|
|
block1
|
|
\family default
|
|
, in which case
|
|
\family typewriter
|
|
block2
|
|
\family default
|
|
must also be provided.
|
|
\layout Description
|
|
|
|
block2 can be either a command or a single program block.
|
|
If
|
|
\family typewriter
|
|
condition
|
|
\family default
|
|
was false and
|
|
\family typewriter
|
|
block2
|
|
\family default
|
|
was provided, it will be executed instead of
|
|
\family typewriter
|
|
block1
|
|
\family default
|
|
.
|
|
\layout Standard
|
|
|
|
The simplest form of
|
|
\family typewriter
|
|
if
|
|
\family default
|
|
is shown in Figure
|
|
\begin_inset LatexCommand \vref{cap:if-simple}
|
|
|
|
\end_inset
|
|
|
|
.
|
|
Because the number 1 is non-zero and thus considered true, the program
|
|
block will be executed and text will be printed.
|
|
\layout Standard
|
|
|
|
|
|
\begin_inset Float figure
|
|
wide false
|
|
collapsed false
|
|
|
|
\layout LyX-Code
|
|
\line_top \line_bottom
|
|
|
|
\begin_inset Include \verbatiminput{if-simple.gib}
|
|
preview false
|
|
|
|
\end_inset
|
|
|
|
|
|
\layout Standard
|
|
|
|
|
|
\series bold
|
|
Output:
|
|
\layout LyX-Code
|
|
|
|
|
|
\begin_inset Include \verbatiminput{if-simple.gib.out}
|
|
preview false
|
|
|
|
\end_inset
|
|
|
|
|
|
\layout Caption
|
|
|
|
Simple
|
|
\family typewriter
|
|
if
|
|
\family default
|
|
structure
|
|
\begin_inset LatexCommand \label{cap:if-simple}
|
|
|
|
\end_inset
|
|
|
|
|
|
\end_inset
|
|
|
|
|
|
\layout Standard
|
|
|
|
Figure
|
|
\begin_inset LatexCommand \vref{cap:if-else}
|
|
|
|
\end_inset
|
|
|
|
is similar to Figure
|
|
\begin_inset LatexCommand \ref{cap:if-simple}
|
|
|
|
\end_inset
|
|
|
|
, but includes an
|
|
\family typewriter
|
|
else
|
|
\family default
|
|
structure.
|
|
The condition argument is false, and thus the second program block is executed.
|
|
\layout Standard
|
|
|
|
|
|
\begin_inset Float figure
|
|
wide false
|
|
collapsed false
|
|
|
|
\layout LyX-Code
|
|
\line_top \line_bottom
|
|
|
|
\begin_inset Include \verbatiminput{if-else.gib}
|
|
preview false
|
|
|
|
\end_inset
|
|
|
|
|
|
\layout Standard
|
|
|
|
|
|
\series bold
|
|
Output:
|
|
\layout LyX-Code
|
|
|
|
|
|
\begin_inset Include \verbatiminput{if-else.gib.out}
|
|
preview false
|
|
|
|
\end_inset
|
|
|
|
|
|
\layout Caption
|
|
|
|
|
|
\family typewriter
|
|
if/else
|
|
\family default
|
|
structure
|
|
\begin_inset LatexCommand \label{cap:if-else}
|
|
|
|
\end_inset
|
|
|
|
|
|
\end_inset
|
|
|
|
|
|
\layout Standard
|
|
|
|
Besides a program block, a simple command may follow
|
|
\family typewriter
|
|
else
|
|
\family default
|
|
, including another
|
|
\family typewriter
|
|
if
|
|
\family default
|
|
structure.
|
|
This allows
|
|
\family typewriter
|
|
if
|
|
\family default
|
|
structures to be chained together.
|
|
The first structure that is true will be the one executed, as shown by
|
|
Figure
|
|
\begin_inset LatexCommand \ref{cap:if-chain}
|
|
|
|
\end_inset
|
|
|
|
.
|
|
\layout Standard
|
|
|
|
|
|
\begin_inset Float figure
|
|
wide false
|
|
collapsed false
|
|
|
|
\layout LyX-Code
|
|
\line_top \line_bottom
|
|
|
|
\begin_inset Include \verbatiminput{if-chain.gib}
|
|
preview false
|
|
|
|
\end_inset
|
|
|
|
|
|
\layout Standard
|
|
|
|
|
|
\series bold
|
|
Output:
|
|
\layout LyX-Code
|
|
|
|
|
|
\begin_inset Include \verbatiminput{if-chain.gib.out}
|
|
preview false
|
|
|
|
\end_inset
|
|
|
|
|
|
\layout Caption
|
|
|
|
Chained
|
|
\family typewriter
|
|
if
|
|
\family default
|
|
structures
|
|
\begin_inset LatexCommand \label{cap:if-chain}
|
|
|
|
\end_inset
|
|
|
|
|
|
\end_inset
|
|
|
|
|
|
\layout Standard
|
|
|
|
Remember that
|
|
\family typewriter
|
|
ifnot
|
|
\family default
|
|
may always be used in place of
|
|
\family typewriter
|
|
if
|
|
\family default
|
|
to reverse
|
|
\family typewriter
|
|
condition
|
|
\family default
|
|
.
|
|
\layout Subsection
|
|
|
|
Loops
|
|
\layout Subsubsection
|
|
|
|
|
|
\family typewriter
|
|
while
|
|
\layout Standard
|
|
|
|
The
|
|
\family typewriter
|
|
while
|
|
\family default
|
|
structure is very similar to a basic
|
|
\family typewriter
|
|
if
|
|
\family default
|
|
structure, except that the program block is continuously executed as long
|
|
as the condition argument is
|
|
\begin_inset Quotes eld
|
|
\end_inset
|
|
|
|
true.
|
|
\begin_inset Quotes erd
|
|
\end_inset
|
|
|
|
The formal syntax is:
|
|
\layout LyX-Code
|
|
|
|
|
|
\family sans
|
|
while
|
|
\family default
|
|
condition block
|
|
\layout Description
|
|
|
|
condition is the same as
|
|
\family typewriter
|
|
condition
|
|
\family default
|
|
in an
|
|
\family typewriter
|
|
if
|
|
\family default
|
|
structure; all non-zero numbers are
|
|
\begin_inset Quotes eld
|
|
\end_inset
|
|
|
|
true,
|
|
\begin_inset Quotes erd
|
|
\end_inset
|
|
|
|
anything else is false.
|
|
If condition is true, block will be executed.
|
|
\layout Description
|
|
|
|
block must be a program block argument.
|
|
If
|
|
\family typewriter
|
|
condition
|
|
\family default
|
|
is true, it will be executed.
|
|
After it has been executed,
|
|
\family typewriter
|
|
condition
|
|
\family default
|
|
will be checked again.
|
|
As long as
|
|
\family typewriter
|
|
condition
|
|
\family default
|
|
is true,
|
|
\family typewriter
|
|
block
|
|
\family default
|
|
will be continually executed.
|
|
\layout Standard
|
|
|
|
Figure
|
|
\begin_inset LatexCommand \vref{cap:while}
|
|
|
|
\end_inset
|
|
|
|
shows an example
|
|
\family typewriter
|
|
while
|
|
\family default
|
|
loop and its output.
|
|
\layout Standard
|
|
|
|
|
|
\begin_inset Float figure
|
|
wide false
|
|
collapsed false
|
|
|
|
\layout LyX-Code
|
|
\line_top \line_bottom
|
|
|
|
\begin_inset Include \verbatiminput{while.gib}
|
|
preview false
|
|
|
|
\end_inset
|
|
|
|
|
|
\layout Standard
|
|
|
|
|
|
\series bold
|
|
Output:
|
|
\layout LyX-Code
|
|
|
|
|
|
\begin_inset Include \verbatiminput{while.gib.out}
|
|
preview false
|
|
|
|
\end_inset
|
|
|
|
|
|
\layout Caption
|
|
|
|
Example
|
|
\family typewriter
|
|
while
|
|
\family default
|
|
loop.
|
|
\begin_inset LatexCommand \label{cap:while}
|
|
|
|
\end_inset
|
|
|
|
|
|
\end_inset
|
|
|
|
|
|
\layout Subsubsection
|
|
|
|
|
|
\family typewriter
|
|
for
|
|
\layout Standard
|
|
|
|
The for loop executes a program block once for every argument in a list.
|
|
Each execution, a variable will be set to the value of the current argument.
|
|
Syntax:
|
|
\layout LyX-Code
|
|
|
|
|
|
\family sans
|
|
for
|
|
\family default
|
|
variable
|
|
\family sans
|
|
in
|
|
\family default
|
|
list block
|
|
\layout Description
|
|
|
|
variable is the variable that will be set to the value of the current argument
|
|
each time the program block is executed.
|
|
\layout Description
|
|
|
|
in is a simple placeholder between
|
|
\family typewriter
|
|
variable
|
|
\family default
|
|
and
|
|
\family typewriter
|
|
list
|
|
\family default
|
|
.
|
|
It emphasizes the fact that
|
|
\emph on
|
|
for
|
|
\emph default
|
|
each argument
|
|
\emph on
|
|
in
|
|
\emph default
|
|
the list, the program block will be executed.
|
|
\layout Description
|
|
|
|
list can be any number of arguments, including expansions.
|
|
\layout Description
|
|
|
|
block must be the last argument to
|
|
\family typewriter
|
|
for
|
|
\family default
|
|
, and it must be a program block.
|
|
\layout Standard
|
|
|
|
Figure
|
|
\begin_inset LatexCommand \vref{cap:for}
|
|
|
|
\end_inset
|
|
|
|
shows an example
|
|
\family typewriter
|
|
for
|
|
\family default
|
|
loop and its output.
|
|
\layout Standard
|
|
|
|
|
|
\begin_inset Float figure
|
|
wide false
|
|
collapsed false
|
|
|
|
\layout LyX-Code
|
|
\line_top \line_bottom
|
|
|
|
\begin_inset Include \verbatiminput{for.gib}
|
|
preview false
|
|
|
|
\end_inset
|
|
|
|
|
|
\layout Standard
|
|
|
|
|
|
\series bold
|
|
Output:
|
|
\layout LyX-Code
|
|
|
|
|
|
\begin_inset Include \verbatiminput{for.gib.out}
|
|
preview false
|
|
|
|
\end_inset
|
|
|
|
|
|
\layout Caption
|
|
|
|
Example
|
|
\family typewriter
|
|
for
|
|
\family default
|
|
loop
|
|
\begin_inset LatexCommand \label{cap:for}
|
|
|
|
\end_inset
|
|
|
|
|
|
\end_inset
|
|
|
|
|
|
\layout Subsubsection
|
|
|
|
Additional Loop Functions:
|
|
\family typewriter
|
|
break
|
|
\family default
|
|
and
|
|
\family typewriter
|
|
continue
|
|
\layout Standard
|
|
|
|
Two functions are available to control the behavior of loops during execution
|
|
of their program blocks:
|
|
\layout Description
|
|
|
|
break immediately ends the program block and leaves the loop.
|
|
\layout Description
|
|
|
|
continue returns to the top of the loop.
|
|
This means that
|
|
\family typewriter
|
|
while
|
|
\family default
|
|
loops check their condition argument again and
|
|
\family typewriter
|
|
for
|
|
\family default
|
|
loops move to the next argument in the list.
|
|
\layout Standard
|
|
|
|
Figure
|
|
\begin_inset LatexCommand \vref{cap:break}
|
|
|
|
\end_inset
|
|
|
|
shows an example use of
|
|
\family typewriter
|
|
break
|
|
\family default
|
|
and its output, while Figure
|
|
\begin_inset LatexCommand \ref{cap:continue}
|
|
|
|
\end_inset
|
|
|
|
shows an example use of
|
|
\family typewriter
|
|
continue
|
|
\family default
|
|
.
|
|
\layout Standard
|
|
|
|
|
|
\begin_inset Float figure
|
|
wide false
|
|
collapsed false
|
|
|
|
\layout LyX-Code
|
|
\line_top \line_bottom
|
|
|
|
\begin_inset Include \verbatiminput{break.gib}
|
|
preview false
|
|
|
|
\end_inset
|
|
|
|
|
|
\layout Standard
|
|
|
|
|
|
\series bold
|
|
Output:
|
|
\layout LyX-Code
|
|
|
|
|
|
\begin_inset Include \verbatiminput{break.gib.out}
|
|
preview false
|
|
|
|
\end_inset
|
|
|
|
|
|
\layout Caption
|
|
|
|
Example use of
|
|
\family typewriter
|
|
break
|
|
\begin_inset LatexCommand \label{cap:break}
|
|
|
|
\end_inset
|
|
|
|
|
|
\end_inset
|
|
|
|
|
|
\layout Standard
|
|
|
|
|
|
\begin_inset Float figure
|
|
wide false
|
|
collapsed false
|
|
|
|
\layout LyX-Code
|
|
\line_top \line_bottom
|
|
|
|
\begin_inset Include \verbatiminput{continue.gib}
|
|
preview false
|
|
|
|
\end_inset
|
|
|
|
|
|
\layout Standard
|
|
|
|
|
|
\series bold
|
|
Output:
|
|
\layout LyX-Code
|
|
|
|
|
|
\begin_inset Include \verbatiminput{continue.gib.out}
|
|
preview false
|
|
|
|
\end_inset
|
|
|
|
|
|
\layout Caption
|
|
|
|
Example use of
|
|
\family typewriter
|
|
continue
|
|
\begin_inset LatexCommand \label{cap:continue}
|
|
|
|
\end_inset
|
|
|
|
|
|
\end_inset
|
|
|
|
|
|
\layout Section
|
|
\pagebreak_top
|
|
Functions
|
|
\layout Subsection
|
|
|
|
Types and Concepts
|
|
\layout Subsection
|
|
|
|
Defining Functions
|
|
\layout Subsection
|
|
|
|
Accessing Arguments
|
|
\layout Subsection
|
|
|
|
Return Values
|
|
\layout Subsubsection
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Returning Values from Functions
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\layout Subsubsection
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Embedding Return Values
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\layout Subsubsection
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Expanding Return Values
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\the_end
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