Update a configuration file where \<expr\> is a dot-separated human-readable [path expression](#ii-path-expressions) and \<content\> is a string or a file. If a string is given, it will <u>override/add the field</u> ; if a file is given the configuration file will be <u>replaced</u> by it.
| `location` | Path to the configuration file to edit. The file will be created if not found. | `/etc/ssh/sshd_config`, `/etc/nginx/nginx.conf`, `/etc/nginx/sites-available/default` |
| `field.path` | Dot-separated chain of strings that match with a configuration field. If **omitted**, the \<value\> will just be added at the end of the configuration file. In the same way if the field does not point to a raw field but a parent or group containing fields, the \<value\> will be added to the group. | `/etc/ssh/sshd_config@AllowGroups`, `/etc/nginx/nginx.conf@http.gzip` |
Configuration files can be written according to some standards or application-specific syntax. This tool uses standard and third-party to parse the following formats :
- [xml](https://fr.wikipedia.org/wiki/Extensible_Markup_Language) and [json](https://json.org/) are read/written using the go standard library (_cf. [json](https://golang.org/pkg/encoding/json/), [xml](https://golang.org/pkg/encoding/xml/)_).
- [yaml](https://en.wikipedia.org/wiki/YAML) with [go-yaml/yaml](https://github.com/go-yaml/yaml).
- [ini](https://en.wikipedia.org/wiki/INI_file) with [go-ini/ini](https://github.com/go-ini/ini).
-<strike>[toml](https://en.wikipedia.org/wiki/TOML)</strike> with [BurntSushi/toml](https://github.com/BurntSushi/toml).
> not consistent ; overriding a toml file with this can mess with comments and duplicate sections. Also there is type inference to do (strings are surrounded with `"`, there is `true`, `false`, etc)
- [nginx configurations](https://docs.nginx.com/nginx/admin-guide/basic-functionality/managing-configuration-files/) with [lytics/confl](https://github.com/lytics/confl).
