src/mount.rs: add mount module to display old archive version

src/mount.rs

+use crate::commit;
+use std::fs;
+use std::path::PathBuf;
+use std::process::{exit, Command};
+
+/// Get the path of the .mount folder
+///
+/// # Description
+/// Get the path of the .mount folder at the root of the project folder. if it
+/// doesn't exits, then creates it
+fn get_mount_folder(borgfolder: &PathBuf) -> PathBuf {
+    let mut mount_folder = borgfolder.parent().unwrap().to_path_buf();
+    mount_folder.push(".mount");
+    if !mount_folder.is_dir() {
+        fs::create_dir(&mount_folder).expect("Unable to create .mount directory");
+    }
+    mount_folder
+}
+
+pub fn mount_archive(commit: &Option<String>, path: &Option<String>, versions: bool) -> () {
+    let (borg_folder, _) = commit::check_path();
+    let mount_folder = get_mount_folder(&borg_folder);
+    let globp = match commit {
+        Some(g) => format!("-a '{}'", g),
+        None => String::from(""),
+    };
+    let mp = match path {
+        Some(p) => String::from(p),
+        None => String::from(""),
+    };
+    let vopt = match versions {
+        true => String::from("-o versions"),
+        false => String::from(""),
+    };
+    let cmd = format!(
+        "borg mount {} {} {} {} {}",
+        globp,
+        vopt,
+        borg_folder.to_str().unwrap(),
+        mount_folder.to_str().unwrap(),
+        mp
+    );
+    let output = Command::new("sh").arg("-c").arg(cmd).output().unwrap();
+    match output.status.code().unwrap() {
+        0 => (),
+        num => {
+            eprintln!("{}", String::from_utf8(output.stderr).unwrap());
+            exit(num);
+        }
+    }
+}
+
+/// Unount an borg archive mounted in .mount folder
+pub fn umount_archive() -> () {
+    let (borg_folder, _) = commit::check_path();
+    let mount_folder = get_mount_folder(&borg_folder);
+    let cmd = format!("borg umount {}", mount_folder.to_str().unwrap());
+    let output = Command::new("sh").arg("-c").arg(cmd).output().unwrap();
+    match output.status.code().unwrap() {
+        0 => (),
+        num => {
+            eprintln!("{}", String::from_utf8(output.stderr).unwrap());
+            exit(num);
+        }
+    }
+}