Add tree view

src/main.rs

@@ -1,5 +1,6 @@
 use itertools::Itertools;
-use processes::terminate_process;
+use processes::{terminate_process, ProcessInfo};
+use std::collections::HashMap;
 use std::process::ExitCode;
 use std::{env, fmt::Display};
 
@@ -9,6 +10,7 @@ mod processes;
 enum Mode {
     Minimal,
     All,
+    Tree,
     Filtered(String),
     Single(String),
     TerminateByPid(u32),
@@ -27,6 +29,10 @@ fn main() -> ExitCode {
             show_processes_table(processes::list_processes());
             ExitCode::SUCCESS
         }
+        Mode::Tree => {
+            show_processes_tree();
+            ExitCode::SUCCESS
+        }
         Mode::Minimal => {
             let filterlist = [
                 "svchost",
@@ -94,6 +100,7 @@ fn main() -> ExitCode {
                 "pkill                         => all unique processed, excl. system\n",
                 "pkill <name>                  => filtered processes by name or it's part\n",
                 "pkill -a/--all                => all processes, incl. system\n",
+                "pkill -t/--tree               => all processes as tree\n",
                 "pkill -p/--pid <name>         => PID of the first occurence\n",
                 "pkill -k1/--kill <PID>/<name> => terminate process by its PID or name\n",
                 "pkill -h/--help               => print help\n",
@@ -110,9 +117,8 @@ fn parse_mode() -> Mode {
     while let Some(el) = iter.next() {
         match el.as_str() {
             "-h" | "--help" => mode = Mode::Help,
-            "-a" | "--all" => {
-                mode = Mode::All;
-            }
+            "-a" | "--all" => mode = Mode::All,
+            "-t" | "--tree" => mode = Mode::Tree,
             "-p" | "--pid" => {
                 if let Some(name) = iter.next() {
                     mode = Mode::Single(name.to_ascii_lowercase());
@@ -139,6 +145,44 @@ fn parse_mode() -> Mode {
     mode
 }
 
+fn show_processes_tree() {
+    let processes: Vec<ProcessInfo> = processes::list_processes()
+        .into_iter()
+        .sorted_by_key(|p| p.parent_pid)
+        .collect();
+
+    let by_pid: HashMap<u32, ProcessInfo> =
+        processes.clone().into_iter().map(|p| (p.pid, p)).collect();
+    let mut tree: HashMap<u32, Vec<ProcessInfo>> = HashMap::new();
+    let mut roots: Vec<ProcessInfo> = Vec::new();
+    for p in processes {
+        if p.pid != p.parent_pid && by_pid.contains_key(&p.parent_pid) {
+            tree.entry(p.parent_pid).or_default().push(p);
+        } else {
+            roots.push(p);
+        }
+    }
+
+    println!("{:60} {:10} {:8}", "Name", "PID", "Threads");
+    for root in roots {
+        display_process_tree(root, &tree, 0);
+    }
+}
+
+fn display_process_tree(p: ProcessInfo, tree: &HashMap<u32, Vec<ProcessInfo>>, depth: usize) {
+    println!(
+        "{:<60} {:<10} {:<8}",
+        " ".repeat(depth * 2) + p.name.as_str(),
+        p.pid,
+        p.threads_count
+    );
+    if let Some(children) = tree.get(&p.pid) {
+        for child in children {
+            display_process_tree(child.clone(), tree, depth + 1);
+        }
+    }
+}
+
 fn show_processes_table<T>(items: T)
 where
     T: IntoIterator,

src/processes.rs

@@ -11,6 +11,7 @@ use windows::Win32::{
     },
 };
 
+#[derive(Clone)]
 pub struct ProcessInfo {
     pub pid: u32,
     pub parent_pid: u32,