Go: Access environment variables

Use the os.Setenv, os.Getenv and os.Unsetenv functions to access environment variables:

fmt.Printf("%q\n", os.Getenv("SHELL")) // "/bin/bash"

os.Unsetenv("SHELL")
fmt.Printf("%q\n", os.Getenv("SHELL")) // ""

os.Setenv("SHELL", "/bin/dash")
fmt.Printf("%q\n", os.Getenv("SHELL")) // "/bin/dash"

The os.Environ function returns a slice of "key=value" strings listing all environment variables.

for _, s := range os.Environ() {
        kv := strings.SplitN(s, "=", 2) // unpacks "key=value"
        fmt.Printf("key:%q value:%q\n", kv[0], kv[1])
}

key:"SHELL" value:"/bin/bash"
key:"SESSION" value:"ubuntu"
key:"TERM" value:"xterm-256color"
key:"LANG" value:"en_US.UTF-8"
key:"XMODIFIERS" value:"@im=ibus"
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