A compound variable file is a text format for serializing the value of a compound variable in a shell. A compound variable consists of variable assignments separated by newlines, where each assignment has a name, optional data type, and value. The file format supports various data types including strings, integers, floats, arrays, binaries, and nested compound variables. Examples show compound variables containing simple values, indexed arrays, sparse indexed arrays, and associative arrays.

1. File Formats compound_var(4)
NAME
compound_var - format of serialised compound variable
DESCRIPTION
An serialised compound variable file is text representing
the value of a compound variable. A compound variable has the form
name=(assignment ...) where "assignment" is a sequence of zero
or more shell variable assignments in the form
[<datatype><blank>]<name>=<value> (if <datatype><blank> is
omitted the default shell datatype "string" will be used)
seperated by newline or ';'.
* DataTypes:
<needs to be written.
* Material:
string
integer (and unsigned integer)
float (conformant to IEEE 754-2008)
hexfloat (conformant to C99 and IEEE 754-2008)
Array, indexed+associative
binary (mime base64)
compound variable
>
* Value encodings:
<needs to be written.
* Material:
1. plain strings
2. plain strings in double-quotes
3. ANSI-C strings $'...'
>
* Indexed arrays, sets, associative arrays:
<needs to be written>
SEE ALSO
ksh93(1), XML(4), libcompoundvar(3c)
NOTES
It is recommended that applications implement compund variable
output using the option "-C compound" or - if "-C" is already
used - use option "-# compound".
The format supports multibyte charatcers for both variable names
and values but the users but ensure that the creator and consumers
use a compatible character encoding.
The recommended file extension for serialised compound variables
is *.cpv
EXAMPLES
1. Empty compound variable:
-- snip --
(
)
-- snip --

2. 2. Compound variable with a string member variable "foo"
-- snip --
(
foo="bar"
)
-- snip --
3. Compound variable with an indexed array with values "1", "2" and "3":
-- snip --
(
typeset -a a=(
1
2
3
)
)
-- snip --
4. Compound variable with an indexed array with string values "1",
"2" and "3":
-- snip --
(
typeset -a a=(
1
2
3
)
)
-- snip --
5. Compound variable with a sparse indexed array containing strings:
-- snip --
(
typeset -a a=(
[0]=1
[3]=3
[5]=2
)
)
-- snip --
6. Compound variable with a sparse indexed array containing
compound variables:
-- snip --
(
typeset -C -a a=(
[4]=(
msg="hello world"
food="roasted chicken"
)
[7]=(
msg="thank you for the fish"
food="tuna"
)
[9]=(
typeset -l -E temp=0.1
typeset -C nested_node=(
name="text node"
description="a text node"
value="hello fish"
)
)
)

3. )
-- snip --
7. Compound variable with an associative array containing
compound variables:
-- snip --
(
typeset -C -a a=(
['a meal node']=(
msg="hello world"
food="roasted chicken"
)
['another meal node']=(
msg="thank you for the fish"
food="tuna"
)
['temperature difference']=(
typeset -l -E temp=0.1
)
)
)
-- snip --
#### Material: ####
* Use sccsfile(4) as template
* String literals:
1. plain strings
2. Plain strings in double-quotes
3. ANSI-C strings $'...'
* Datatypes:
string
integer (and unsigned integer)
float (conformant to IEEE 754-2008)
hexfloat (conformant to C99 and IEEE 754-2008)
Array, indexed+associative
binary (mime base64)
compound variable
* ToDo:
-- snip --
<plocher> define the stability and specs for the following: Name,
Grammer/Syntax,
Producer(s) and Consumer(s), as well as a Description of what the file is used
for,
how its content can evolve (i.e., presume the parser stays same, but the grammer
grows, how can Consumers deal with change...)
-- snip --