INI [](https://travis-ci.org/go-ini/ini) [](https://sourcegraph.com/github.com/go-ini/ini?badge)
Package ini provides INI file read and write functionality in Go.
[简体中文](README_ZH.md)
## Feature
- Load multiple data sources(`[]byte`, file and `io.ReadCloser`) with overwrites.
- Read with recursion values.
- Read with parent-child sections.
- Read with auto-increment key names.
- Read with multiple-line values.
- Read with tons of helper methods.
- Read and convert values to Go types.
- Read and **WRITE** comments of sections and keys.
- Manipulate sections, keys and comments with ease.
- Keep sections and keys in order as you parse and save.
## Installation
To use a tagged revision:
go get gopkg.in/ini.v1
To use with latest changes:
go get github.com/go-ini/ini
Please add `-u` flag to update in the future.
### Testing
If you want to test on your machine, please apply `-t` flag:
go get -t gopkg.in/ini.v1
Please add `-u` flag to update in the future.
## Getting Started
### Loading from data sources
A **Data Source** is either raw data in type `[]byte`, a file name with type `string` or `io.ReadCloser`. You can load **as many data sources as you want**. Passing other types will simply return an error.
```go
cfg, err := ini.Load([]byte("raw data"), "filename", ioutil.NopCloser(bytes.NewReader([]byte("some other data"))))
```
Or start with an empty object:
```go
cfg := ini.Empty()
```
When you cannot decide how many data sources to load at the beginning, you will still be able to **Append()** them later.
```go
err := cfg.Append("other file", []byte("other raw data"))
```
If you have a list of files with possibilities that some of them may not available at the time, and you don't know exactly which ones, you can use `LooseLoad` to ignore nonexistent files without returning error.
For a shortcut for default section, just give an empty string as name:
```go
section, err := cfg.GetSection("")
```
When you're pretty sure the section exists, following code could make your life easier:
```go
section := cfg.Section("section name")
```
What happens when the section somehow does not exist? Don't panic, it automatically creates and returns a new section to you.
To create a new section:
```go
err := cfg.NewSection("new section")
```
To get a list of sections or section names:
```go
sections := cfg.Sections()
names := cfg.SectionStrings()
```
### Working with keys
To get a key under a section:
```go
key, err := cfg.Section("").GetKey("key name")
```
Same rule applies to key operations:
```go
key := cfg.Section("").Key("key name")
```
To check if a key exists:
```go
yes := cfg.Section("").HasKey("key name")
```
To create a new key:
```go
err := cfg.Section("").NewKey("name", "value")
```
To get a list of keys or key names:
```go
keys := cfg.Section("").Keys()
names := cfg.Section("").KeyStrings()
```
To get a clone hash of keys and corresponding values:
```go
hash := cfg.Section("").KeysHash()
```
### Working with values
To get a string value:
```go
val := cfg.Section("").Key("key name").String()
```
To validate key value on the fly:
```go
val := cfg.Section("").Key("key name").Validate(func(in string) string {
if len(in) == 0 {
return "default"
}
return in
})
```
If you do not want any auto-transformation (such as recursive read) for the values, you can get raw value directly (this way you get much better performance):
```go
val := cfg.Section("").Key("key name").Value()
```
To check if raw value exists:
```go
yes := cfg.Section("").HasValue("test value")
```
To get value with types:
```go
// For boolean values:
// true when value is: 1, t, T, TRUE, true, True, YES, yes, Yes, y, ON, on, On
// false when value is: 0, f, F, FALSE, false, False, NO, no, No, n, OFF, off, Off
Finally, it's time to save your configuration to somewhere.
A typical way to save configuration is writing it to a file:
```go
// ...
err = cfg.SaveTo("my.ini")
err = cfg.SaveToIndent("my.ini", "\t")
```
Another way to save is writing to a `io.Writer` interface:
```go
// ...
cfg.WriteTo(writer)
cfg.WriteToIndent(writer, "\t")
```
By default, spaces are used to align "=" sign between key and values, to disable that:
```go
ini.PrettyFormat = false
```
## Advanced Usage
### Recursive Values
For all value of keys, there is a special syntax `%(<name>)s`, where `<name>` is the key name in same section or default section, and `%(<name>)s` will be replaced by corresponding value(empty string if key not found). You can use this syntax at most 99 level of recursions.
You can use `.` in section name to indicate parent-child relationship between two or more sections. If the key not found in the child section, library will try again on its parent section until there is no parent section.
<1><L.Slide#2> This slide has the fuel listed in the wrong units <e.1>`))
body := cfg.Section("COMMENTS").Body()
/* --- start ---
<1><L.Slide#2> This slide has the fuel listed in the wrong units <e.1>
------ end --- */
```
### Auto-increment Key Names
If key name is `-` in data source, then it would be seen as special syntax for auto-increment key name start from 1, and every section is independent on counter.
```ini
[features]
-: Support read/write comments of keys and sections
-: Support auto-increment of key names
-: Support load multiple files to overwrite key values
To save your time and make your code cleaner, this library supports [`NameMapper`](https://gowalker.org/gopkg.in/ini.v1#NameMapper) between struct field and actual section and key name.
There are 2 built-in name mappers:
-`AllCapsUnderscore`: it converts to format `ALL_CAPS_UNDERSCORE` then match section or key.
-`TitleUnderscore`: it converts to format `title_underscore` then match section or key.
- [File An Issue](https://github.com/go-ini/ini/issues/new)
## FAQs
### What does `BlockMode` field do?
By default, library lets you read and write values so we need a locker to make sure your data is safe. But in cases that you are very sure about only reading data through the library, you can set `cfg.BlockMode = false` to speed up read operations about **50-70%** faster.
### Why another INI library?
Many people are using my another INI library [goconfig](https://github.com/Unknwon/goconfig), so the reason for this one is I would like to make more Go style code. Also when you set `cfg.BlockMode = false`, this one is about **10-30%** faster.
To make those changes I have to confirm API broken, so it's safer to keep it in another place and start using `gopkg.in` to version my package at this time.(PS: shorter import path)
## License
This project is under Apache v2 License. See the [LICENSE](LICENSE) file for the full license text.
