macro_rules! show_environment {
    (@cmd ($cmd:expr) -h, $($tail:tt)*) => { ... };
    (@cmd ($cmd:expr) -g, $($tail:tt)*) => { ... };
    (@cmd ($cmd:expr) -s, $($tail:tt)*) => { ... };
    (@cmd ($cmd:expr) -t $target_session:expr, $($tail:tt)*) => { ... };
    (@cmd ($cmd:expr) $variable:expr, $($tail:tt)*) => { ... };
    (@cmd ($cmd:expr)) => { ... };
    () => { ... };
    (($cmd:expr), $($tail:tt)*) => { ... };
    ($($tail:tt)*) => { ... };
}
Expand description

§Manual

tmux ^3.2:

show-environment [-hgs] [-t target-session] [variable]
(alias: showenv)

tmux ^2.1:

show-environment [-gs] [-t target-session] [variable]
(alias: showenv)

tmux ^1.7:

show-environment [-g] [-t target-session] [variable]
(alias: showenv)

tmux ^1.0:

show-environment [-g] [-t target-session]
(alias: showenv)