gosimpleconf

gosimpleconf

go get git.wisellama.rocks/Wisellama/gosimpleconf@v0.1.0

This is a small library for parsing super simple configuration files similar to Unix conf files.

It expects a file with the following format:

• Lines with key-values pairs separated by = (e.g. foo = bar)
• Lines that start with # are ignored (used for comments)
• Empty and whitespace-only lines are ignored
• Lines with some data but no = will cause an error.
• Lines with multiple = are split on the literal first = seen, any remaining are part of the value.

The key-values pairs are simply parsed as strings and plopped into a map for you to do whatever your program wants with them. If you need a value to not be a string, you will have to convert the value from a string as needed for your program (e.g. using the strconv library).

Example

Here's an example config file file.conf

url = www.wisellama.rocks
number_of_widgets = 1337
pi = 3.141592653589793238462643383
environment = production

# Quotes are optional
name = Dude guy
description = "Just some dude it was"

# Additional equals are just part of the value
base64_tacos = dGFjb3M=
a=b=c
# key: 'a', value: 'b=c'

Then to load that config file into a map:

configMap, err := gosimpleconf.Configure("file.conf")

Then everything is a string. You can parse it as needed.

var piStr string = configMap["pi"]
pi, err := strconv.ParseFloat(value, 64)

Command-Line Flag Overrides

By default, the Configure() function will figure out which keys exist in the config map and set those as cli flags that you can override. For example, with the config file above, you could override the url key with a cli flag:

./program --url=newthing.wisellama.rocks

If you don't want to support cli flag overrides, you can directly call ReadFile("file.conf") instead.

If you want to support other cli flags that don't map to a config setting, they must be set up before calling Configure(). This is because the ParseFlags() function calls flag.Parse() to get all the values for the config map overrides. You could also work around this by calling ReadFile and ParseFlags yourself and add your other logic in between the two calls.

Default Config

You can specify a default configuration to return if the given config file doesn't exist. Here's an example:

defaultConfig := gosimpleconf.ConfigMap{
	"game.title":      "Some Game",
	"log.writeToFile": "false",
}
configMap, err := gosimpleconf.ConfigureWithDefaults("file_that_doesnt_exist.conf", defaultConfig)

Then if the config file can't be found, the default config map values will be used instead. You can still override the default values with cli flags.

Why?

I've always seen configuration files similar to this show up in Unix-like systems and programs, but it doesn't seem to be fully standardized under a real name other than just "conf files". The closest I've seen are INI files, but those don't seem to fit the style I was looking for (they don't use # for comments and they support sections in square brackets [section]).

Instead, I just wanted the bare minimum configuration format of foo = bar on each line with # for comments. So that's what this library does.

This project looks abandoned

This library is so simple that I almost never expect to need to update it unless Go fundamentally breaks the language in the future. So while the project may eventually look like it has been abandoned, it is rather simply "complete". (gasp I know, such a rare thing in the software world).

License

This project is licensed under the 2-Clause BSD License (a permissive open source license). See License.md for the full text.