General Structure

Configuration files are built from the following simple syntactic structures:

Strings, arrays and dictionaries are classified by the generic term "property".

Remarks can be written in three forms:

/* remark */

as in C,

// remark to end of line

as in C++ or Objective-C

# remark to end of line

as in shell scripts.

Strings are sequences of alphanumeric characters, including the underscore. If a string should consist of other characters like spaces, it must be quoted in double quotes. Within double quotes, the same escape sequences as in C strings can be used. There is no separate syntax for numeric arguments. Numeric arguments are regarded as strings and converted when used.

Arrays are ordered lists of other properties. An array is delimited by parentheses and the properties constituting the array may be separated by commas. The following example is an array consisting of several string elements:

(1, 2, 3, hello, "how are you")

Dictionaries are unordered lists of named properties. These lists are delimited by curly braces. Each dictionary entry consists of a left -hand side (key), which must be a string, an equal sign, and a right -hand side (value) which may be any property. Entries may be separated by semicolons. The following is an example of a dictionary consisting of three entries named property1 to property3 ;where the first one has a string value, the second an array value, and the third a dictionary value:

   {
        property1 = "value of property1";
property2 = (value, of, property2);
property3 = {
firstWord = value;
secondWord = of;
thirdWord = property3;
};
}

The configuration file itself is a dictionary (the surrounding curly braces are optional because other properties are not allowed). The keys at the top level are the names of the configuration variables.

Properties that have been parsed as strings may be interpreted in one of the following ways:

String needs no further explanation. Numbers are interpreted in decimal, unless they are prefixed with 0 (meaning octal), or 0x (meaning hexadecimal). Enumerations are strings from a predefined set of strings. Boolean variables are a special case of enumeration where the set consists of the strings yes and no.