# LibTmux::Session#set_environment

- **Module:** LibTmux
- **Package:** libtmux
- **Language:** Ruby
- **Kind:** method
- **Source:** https://github.com/libtmux/libtmux-ruby/blob/d8ce4bbee0ca7748a81929f81f7d8d07f8c51267/gems/libtmux/lib/libtmux/operations.rb#L275
- **Page:** https://libtmux.org/en/ruby/v0.1.0.alpha.3/reference/libtmux-session-set_environment/

```
def set_environment: (
  ::String,
  ::String,
  ?hidden: bool,
  ?timeout: ::Numeric,
  ?cancel: untyped
) -> ::LibTmux::CommandResult
```

Behavior: Environment.

Behavior contract: Environment.

## Parameters

- `arg1` (`::String`)
- `arg2` (`::String`)
- `hidden` (`bool`)
- `timeout` (`::Numeric`)
- `cancel` (`untyped`)

## In other ports

### Set a variable in a session's environment

- Python: [`libtmux.Session.set_environment`](/en/py/latest/reference/libtmux-session-set_environment/) (method)
- Lua: [`libtmux.Session:set_environment`](/en/lua/latest/reference/libtmux-session-set_environment/) (method)
- TypeScript: [`session.Session.setEnvironment`](/en/ts/latest/reference/session-session-setenvironment/) (method)
- Rust: [`session.Session.set_environment`](/en/rs/latest/reference/session-session-set_environment/) (method)
- Go: [`tmux.Session.SetEnvironment`](/en/go/latest/reference/tmux-session-setenvironment/) (method)
- Swift: [`Server.setEnvironment(_:to:in:)`](/en/swift/latest/reference/server-setenvironment(_-to-in-)/) (method)