Add pre_sudo option (#219)

* Add `pre_sudo` option

src/sudo.rs

@@ -0,0 +1,34 @@
+use std::path::PathBuf;
+
+use color_eyre::eyre::Context;
+use color_eyre::eyre::Result;
+
+use crate::command::CommandExt;
+use crate::execution_context::ExecutionContext;
+use crate::terminal::print_separator;
+use crate::utils::which;
+
+/// Get the path of the `sudo` utility.
+///
+/// Detects `doas`, `sudo`, `gsudo`, or `pkexec`.
+pub fn path() -> Option<PathBuf> {
+    which("doas")
+        .or_else(|| which("sudo"))
+        .or_else(|| which("gsudo"))
+        .or_else(|| which("pkexec"))
+}
+
+/// Elevate permissions with `sudo`.
+pub fn elevate(ctx: &ExecutionContext, sudo: Option<&PathBuf>) -> Result<()> {
+    if let Some(sudo) = sudo {
+        print_separator("Sudo");
+        ctx.run_type()
+            .execute(sudo)
+            // TODO: Does this work with `doas`, `pkexec`, `gsudo`, GNU `sudo`...?
+            .arg("-v")
+            .status_checked()
+            .wrap_err("Failed to elevate permissions")?;
+    }
+
+    Ok(())
+}