Added a submenu to list system-declared sessions (#1).

Cargo.lock

@@ -1,5 +1,11 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
+[[package]]
+name = "ahash"
+version = "0.3.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e8fd72866655d1904d6b0997d0b07ba561047d070fbe29de039031c641b61217"
+
 [[package]]
 name = "autocfg"
 version = "1.0.0"
@@ -41,6 +47,15 @@ dependencies = [
  "time",
 ]
 
+[[package]]
+name = "dlv-list"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1b391911b9a786312a10cb9d2b3d0735adfd5a8113eb3648de26a75e91b0826c"
+dependencies = [
+ "rand",
+]
+
 [[package]]
 name = "either"
 version = "1.5.3"
@@ -56,6 +71,17 @@ dependencies = [
  "unicode-width",
 ]
 
+[[package]]
+name = "getrandom"
+version = "0.1.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7abc8dd8451921606d809ba32e95b6111925cd2906060d2dcc29c070220503eb"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "wasi",
+]
+
 [[package]]
 name = "greetd_ipc"
 version = "0.6.0"
@@ -67,6 +93,16 @@ dependencies = [
  "thiserror",
 ]
 
+[[package]]
+name = "hashbrown"
+version = "0.7.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "96282e96bfcd3da0d3aa9938bedf1e50df3269b6db08b4876d2da0bb1a0841cf"
+dependencies = [
+ "ahash",
+ "autocfg",
+]
+
 [[package]]
 name = "itertools"
 version = "0.9.0"
@@ -126,6 +162,22 @@ version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b8f8bdf33df195859076e54ab11ee78a1b208382d3a26ec40d142ffc1ecc49ef"
 
+[[package]]
+name = "ordered-multimap"
+version = "0.2.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e88f947c6799d5eff50e6cf8a2365c17ac4aa8f8f43aceeedc29b616d872a358"
+dependencies = [
+ "dlv-list",
+ "hashbrown",
+]
+
+[[package]]
+name = "ppv-lite86"
+version = "0.2.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "237a5ed80e274dbc66f86bd59c1e25edc039660be53194b5fe0a482e0f2612ea"
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.18"
@@ -144,6 +196,47 @@ dependencies = [
  "proc-macro2",
 ]
 
+[[package]]
+name = "rand"
+version = "0.7.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6a6b1679d49b24bbfe0c803429aa1874472f50d9b363131f0e89fc356b544d03"
+dependencies = [
+ "getrandom",
+ "libc",
+ "rand_chacha",
+ "rand_core",
+ "rand_hc",
+]
+
+[[package]]
+name = "rand_chacha"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f4c8ed856279c9737206bf725bf36935d8666ead7aa69b52be55af369d193402"
+dependencies = [
+ "ppv-lite86",
+ "rand_core",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "90bde5296fc891b0cef12a6d03ddccc162ce7b2aff54160af9338f8d40df6d19"
+dependencies = [
+ "getrandom",
+]
+
+[[package]]
+name = "rand_hc"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ca3129af7b92a17112d59ad498c6f81eaf463253766b90396d39ea7a39d6613c"
+dependencies = [
+ "rand_core",
+]
+
 [[package]]
 name = "redox_syscall"
 version = "0.1.56"
@@ -159,6 +252,16 @@ dependencies = [
  "redox_syscall",
 ]
 
+[[package]]
+name = "rust-ini"
+version = "0.15.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7a3679dd538c876a7b606f3bb951c8a20fc281a0ff7795f59f7cb490e3f979e1"
+dependencies = [
+ "cfg-if",
+ "ordered-multimap",
+]
+
 [[package]]
 name = "ryu"
 version = "1.0.5"
@@ -281,6 +384,7 @@ dependencies = [
  "getopts",
  "greetd_ipc",
  "nix",
+ "rust-ini",
  "termion",
  "textwrap",
  "tui",
@@ -311,6 +415,12 @@ version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6a02e4885ed3bc0f2de90ea6dd45ebcbb66dacffe03547fadbb0eeae2770887d"
 
+[[package]]
+name = "wasi"
+version = "0.9.0+wasi-snapshot-preview1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cccddf32554fecc6acb585f82a32a72e28b48f8c4c1883ddfeeeaa96f7d8e519"
+
 [[package]]
 name = "winapi"
 version = "0.3.9"

Cargo.toml

@@ -14,6 +14,7 @@ nix = "0.17.0"
 textwrap = "0.12.0"
 chrono = "0.4.11"
 zeroize = "1.1.0"
+rust-ini = "0.15.3"
 
 [profile.release]
 lto = true

README.md

@@ -28,7 +28,7 @@ The default configuration tends to be as minimal as possible, visually speaking,
 
 The initial prompt container will be 80 column wide. You may change this with `--width` in case you need more space (for example, to account for large PAM challenge messages). Please refer to usage information (`--help`) for more customizaton options.
 
-You may change the command that will be executed after opening a session by huttint `F2` and amending the command.
+You may change the command that will be executed after opening a session by hittint `F2` and amending the command. Alternatively, you can list the system-declared sessions by hitting `F3`.
 
 ## Install
 

src/config.rs

@@ -32,6 +32,7 @@ pub enum Mode {
   Username,
   Password,
   Command,
+  Sessions,
 }
 
 impl Default for Mode {
@@ -44,18 +45,25 @@ impl Default for Mode {
 pub struct Greeter {
   pub config: Option<Matches>,
   pub stream: Option<UnixStream>,
-  pub command: Option<String>,
-  pub previous_mode: Mode,
-  pub mode: Mode,
   pub request: Option<Request>,
+
+  pub mode: Mode,
+  pub previous_mode: Mode,
   pub cursor_offset: i16,
-  pub username: String,
+
-  pub answer: String,
+  pub command: Option<String>,
   pub new_command: String,
-  pub secret: bool,
+  pub sessions: Vec<(String, String)>,
+  pub selected_session: usize,
+
+  pub username: String,
   pub prompt: String,
+  pub answer: String,
+  pub secret: bool,
+
   pub greeting: Option<String>,
   pub message: Option<String>,
+
   pub working: bool,
   pub done: bool,
 }
@@ -72,9 +80,13 @@ impl Drop for Greeter {
 impl Greeter {
   pub fn new() -> Self {
     let mut greeter = Self::default();
+
     greeter.parse_options();
+    greeter.sessions = crate::info::get_sessions().unwrap_or_default();
+    greeter.selected_session = greeter.sessions.iter().position(|(_, command)| Some(command) == greeter.command.as_ref()).unwrap_or(0);
     greeter
   }
+
   pub fn config(&self) -> &Matches {
     self.config.as_ref().unwrap()
   }

src/info.rs

@@ -1,7 +1,11 @@
-use std::{env, fs};
+use std::{env, error::Error, fs, path::Path};
 
+use ini::Ini;
 use nix::sys::utsname;
 
+const X_SESSIONS: &str = "/usr/share/xsessions";
+const WAYLAND_SESSIONS: &str = "/usr/share/wayland-sessions";
+
 pub fn get_hostname() -> String {
   utsname::uname().nodename().to_string()
 }
@@ -26,3 +30,28 @@ pub fn get_issue() -> Option<String> {
 
   None
 }
+
+pub fn get_sessions() -> Result<Vec<(String, String)>, Box<dyn Error>> {
+  let directories = vec![X_SESSIONS, WAYLAND_SESSIONS];
+
+  let files = directories
+    .iter()
+    .flat_map(|directory| fs::read_dir(&directory))
+    .flat_map(|directory| directory.flat_map(|entry| entry.map(|entry| load_desktop_file(entry.path()))).flatten())
+    .collect::<Vec<_>>();
+
+  Ok(files)
+}
+
+fn load_desktop_file<P>(path: P) -> Result<(String, String), Box<dyn Error>>
+where
+  P: AsRef<Path>,
+{
+  let desktop = Ini::load_from_file(path)?;
+  let section = desktop.section(Some("Desktop Entry")).ok_or("no Desktop Entry section in desktop file")?;
+
+  let name = section.get("Name").ok_or("no Name property in desktop file")?;
+  let exec = section.get("Exec").ok_or("no Exec property in desktop file")?;
+
+  Ok((name.to_string(), exec.to_string()))
+}

src/keyboard.rs

@@ -11,13 +11,10 @@ use crate::{
 pub fn handle(greeter: &mut Greeter, events: &Events) -> Result<(), Box<dyn Error>> {
   if let Event::Input(input) = events.next()? {
     match input {
-      Key::Esc => {
+      Key::Esc => match greeter.mode {
-        if let Mode::Command = greeter.mode {
+        Mode::Command | Mode::Sessions => greeter.mode = greeter.previous_mode,
-          greeter.mode = greeter.previous_mode;
+        _ => crate::exit(greeter, AuthStatus::Cancel)?,
-        } else {
+      },
-          crate::exit(greeter, AuthStatus::Cancel)?;
-        }
-      }
 
       Key::Left => greeter.cursor_offset -= 1,
       Key::Right => greeter.cursor_offset += 1,
@@ -28,6 +25,27 @@ pub fn handle(greeter: &mut Greeter, events: &Events) -> Result<(), Box<dyn Erro
         greeter.mode = Mode::Command;
       }
 
+      Key::F(3) => {
+        greeter.previous_mode = greeter.mode;
+        greeter.mode = Mode::Sessions;
+      }
+
+      Key::Up => {
+        if let Mode::Sessions = greeter.mode {
+          if greeter.selected_session > 0 {
+            greeter.selected_session -= 1;
+          }
+        }
+      }
+
+      Key::Down => {
+        if let Mode::Sessions = greeter.mode {
+          if greeter.selected_session < greeter.sessions.len() - 1 {
+            greeter.selected_session += 1;
+          }
+        }
+      }
+
       Key::Ctrl('a') => greeter.cursor_offset = -(greeter.username.len() as i16),
       Key::Ctrl('e') => greeter.cursor_offset = 0,
 
@@ -52,6 +70,15 @@ pub fn handle(greeter: &mut Greeter, events: &Events) -> Result<(), Box<dyn Erro
 
         Mode::Command => {
           greeter.command = Some(greeter.new_command.clone());
+          greeter.selected_session = greeter.sessions.iter().position(|(_, command)| Some(command) == greeter.command.as_ref()).unwrap_or(0);
+          greeter.mode = greeter.previous_mode;
+        }
+
+        Mode::Sessions => {
+          if let Some((_, command)) = greeter.sessions.get(greeter.selected_session) {
+            greeter.command = Some(command.clone());
+          }
+
           greeter.mode = greeter.previous_mode;
         }
       },
@@ -72,6 +99,7 @@ fn insert_key(greeter: &mut Greeter, c: char) {
     Mode::Username => &mut greeter.username,
     Mode::Password => &mut greeter.answer,
     Mode::Command => &mut greeter.new_command,
+    Mode::Sessions => return,
   };
 
   let index = value.len() as i16 + greeter.cursor_offset;
@@ -84,6 +112,7 @@ fn delete_key(greeter: &mut Greeter, key: Key) {
     Mode::Username => &mut greeter.username,
     Mode::Password => &mut greeter.answer,
     Mode::Command => &mut greeter.new_command,
+    Mode::Sessions => return,
   };
 
   let index = match key {

src/ui/mod.rs

@@ -1,4 +1,5 @@
 mod prompt;
+mod sessions;
 
 use std::{
   error::Error,
@@ -15,9 +16,10 @@ use tui::{
   Terminal,
 };
 
-use crate::Greeter;
+use crate::{Greeter, Mode};
 
 const EXIT: &str = "Exit";
+const SESSIONS: &str = "Choose session";
 const CHANGE_COMMAND: &str = "Change command";
 const COMMAND: &str = "COMMAND";
 
@@ -56,6 +58,8 @@ pub fn draw(terminal: &mut Terminal<TermionBackend<RawTerminal<io::Stdout>>>, gr
       status_value(EXIT),
       status_label("F2"),
       status_value(CHANGE_COMMAND),
+      status_label("F3"),
+      status_value(SESSIONS),
       status_label(COMMAND),
       status_value(command),
     ];
@@ -63,7 +67,10 @@ pub fn draw(terminal: &mut Terminal<TermionBackend<RawTerminal<io::Stdout>>>, gr
 
     f.render_widget(status, chunks[2]);
 
-    cursor = self::prompt::draw(greeter, &mut f).ok();
+    cursor = match greeter.mode {
+      Mode::Sessions => self::sessions::draw(greeter, &mut f).ok(),
+      _ => self::prompt::draw(greeter, &mut f).ok(),
+    }
   })?;
 
   if let Some(cursor) = cursor {

src/ui/prompt.rs

@@ -115,10 +115,12 @@ pub fn draw(greeter: &mut Greeter, f: &mut Frame<TermionBackend<RawTerminal<io::
         match greeter.mode {
           Mode::Username => f.render_widget(message, chunks[ANSWER_INDEX]),
           Mode::Password => f.render_widget(message, chunks[MESSAGE_INDEX]),
-          Mode::Command => {}
+          Mode::Command | Mode::Sessions => {}
         }
       }
     }
+
+    Mode::Sessions => {}
   }
 
   match greeter.mode {
@@ -143,6 +145,8 @@ pub fn draw(greeter: &mut Greeter, f: &mut Frame<TermionBackend<RawTerminal<io::
 
       Ok((2 + cursor.x + COMMAND.len() as u16 + offset as u16, USERNAME_INDEX as u16 + cursor.y))
     }
+
+    Mode::Sessions => Ok((1, 1)),
   }
 }
 
@@ -154,7 +158,8 @@ fn get_height(greeter: &Greeter) -> u16 {
 
   let initial = match greeter.mode {
     Mode::Username | Mode::Command => (2 * container_padding) + 1,
-    Mode::Password => (2 * container_padding) + 2 + (2 * prompt_padding),
+    Mode::Password => (2 * container_padding) + prompt_padding + 2,
+    Mode::Sessions => 0,
   };
 
   match greeter.mode {

src/ui/sessions.rs

@@ -0,0 +1,51 @@
+use std::{error::Error, io};
+
+use termion::raw::RawTerminal;
+use tui::{
+  backend::TermionBackend,
+  layout::Rect,
+  style::{Modifier, Style},
+  widgets::{Block, BorderType, Borders, Paragraph, Text},
+  Frame,
+};
+
+use crate::Greeter;
+
+const CHANGE_SESSION: &str = "Change session";
+
+pub fn draw(greeter: &mut Greeter, f: &mut Frame<TermionBackend<RawTerminal<io::Stdout>>>) -> Result<(u16, u16), Box<dyn Error>> {
+  let size = f.size();
+
+  let width = greeter.width();
+  let height: u16 = greeter.sessions.len() as u16 + 4;
+  let x = (size.width - width) / 2;
+  let y = (size.height - height) / 2;
+
+  let container = Rect::new(x, y, width, height);
+
+  let title = format!(" {} ", CHANGE_SESSION);
+  let block = Block::default().title(&title).borders(Borders::ALL).border_type(BorderType::Plain);
+
+  for (index, (name, _)) in greeter.sessions.iter().enumerate() {
+    let frame = Rect::new(x + 2, y + 2 + index as u16, width, 1);
+    let option_text = [get_option(&greeter, name, index)];
+    let option = Paragraph::new(option_text.iter());
+
+    f.render_widget(option, frame);
+  }
+
+  f.render_widget(block, container);
+
+  Ok((1, 1))
+}
+
+fn get_option<'g, S>(greeter: &Greeter, name: S, index: usize) -> Text<'g>
+where
+  S: Into<String>,
+{
+  if greeter.selected_session == index {
+    Text::styled(name.into(), Style::default().modifier(Modifier::REVERSED))
+  } else {
+    Text::raw(name.into())
+  }
+}