Plugin: kconfig

• infos = Information about the kconfig plugin is in keys below
• infos/author = Dardan Haxhimustafa mail@.nosp@m.dard.nosp@m.an.im
• infos/licence = BSD
• infos/needs =
• infos/provides = storage/kconfig
• infos/recommends =
• infos/placements = getstorage setstorage
• infos/status = recommended maintained compatible specific unittest nodep experimental unfinished concept
• infos/metadata =
• infos/description = Reads and writes the KConfig INI format

Introduction

This plugin can be used to parse and serialize a KConfig INI file.

Information about the syntax:

• Files are expected to be encoded in UTF-8.
• Empty lines are ignored.
• Lines that start with a # character are considered comments. Comments are ignored too.
• Configurations consist of groups and keys. Only keys can have values.
• Key names can't start with a [ character
• Keys can contain spaces and any special characters except =.
• If a key has a value, then it will be followed with an = symbol and then the value will be read until the end of the line. The white space characters around the = symbol are ignored.
• In values, the following escape sequences can be used:
  • \n and \r are mapped to newline
  • \t is mapped to tab
  • \\ is mapped to \
• Values can contain any character from the UTF-8 set except for newline and \ followed by an invalid escape sequence.
• Keys can be localized. The locale is surrounded with [ and ] and cannot start with $.
• Same key names can be used multiple times if it has different locales. The following example is valid:

  greeting[en] = Hello
  greeting[de] = Hallo

• Keys can have metadata. Those are one byte long, start with $ and are surrounded with [ and ].
• The same key name can't be used multiple times with different metadata (different to locales). The following example is invalid:

  key.name[$a] = Something
  key.name[$i] = Something else

• Group names begin have a [ symbol at the beginning of a line and every key that follows them is part of this group (until the next group is declared)

An example of how a valid config file might look like:

[group][subgroup]
key.name[en][$i][$e]=Key Value
key.name[de]=Key Wert

And how it will be represented in kdb:

keyNew (PREFIX "group/subgroup/key.name[en]", KEY_VALUE, "Key Value", KEY_META, "kconfig", "ie", KEY_END)
keyNew (PREFIX "group/subgroup/key.name[de]", KEY_VALUE, "Key Wert", KEY_END)

Usage

The following example shows you how you can read data using this plugin.

# Mount the plugin to the cascading namespace `/tests/kconfig`
sudo kdb mount configrc /tests/kconfig kconfig
 
# Manually add a key-value pair to the database
mkdir -p "$(dirname "$(kdb file user:/tests/kconfig)")"
echo 'key=Value' > "$(kdb file user:/tests/kconfig)"
 
# Retrieve the new value
kdb get /tests/kconfig/key
#> Value
 
# Set the value to Example
kdb set /tests/kconfig/key Example
 
# Verify that the value has changed in the file too
cat `kdb file user:/tests/kconfig`
#> key=Example
 
# Manually add a gorup to the database
echo '[group][subgroup]' >> "$(kdb file user:/tests/kconfig)"
 
# Manually add a key that contains metas to that group
echo 'key.name[$a][$i]=New Value' >> "$(kdb file user:/tests/kconfig)"
 
# Retrieve the new value
kdb get /tests/kconfig/group/subgroup/key.name
#> New Value
 
# Retrieve the meta values
kdb meta-get /tests/kconfig/group/subgroup/key.name kconfig
#> ai
 
# Manually add a group and a localized key
echo '[localized keys]' >> `kdb file user:/tests/kconfig`
echo 'greeting[en]=Hello' >> `kdb file user:/tests/kconfig`
echo 'greeting[de]=Hallo' >> `kdb file user:/tests/kconfig`
 
# Retrieve the english greeting
kdb get '/tests/kconfig/localized keys/greeting[en]'
#> Hello
 
# Retrieve the german greeting
kdb get '/tests/kconfig/localized keys/greeting[de]'
#> Hallo
 
# Undo modifications to the database
sudo kdb umount /tests/kconfig

Limitations

• Comments from the file are discarded on save (same as the default KConfig functionality)
• No validation for meta values or locale codes