clap is weird

bash_setup.sh

@@ -2,15 +2,20 @@
 
 export PATH="$PATH:$PWD/target/debug/"
 pid=( $(ps -o ppid) )
+arg_pid=" --pid ${pid[-2]} "
 
 nav() {
-    cd "$(navigate ${pid[-2]} $*)"
+    cd "$(navigate ${arg_pid} $*)"
 }
 
 push() {
-    cd "$(navigate ${pid[-2]} push $*)"
+    cd "$(navigate push ${arg_pid} $*)"
 }
 
 pop() {
-    cd "$(navigate ${pid[-2]} pop $*)"
+    cd "$(navigate pop ${arg_pid} $*)"
 }
+
+stack() {
+    "navigate stack ${arg_pid}"
+}

src/args.rs

@@ -0,0 +1,61 @@
+use clap:: {Parser, Args, Subcommand};
+
+/// implements stack for cd wrapper script
+#[derive(Debug, Parser)]
+#[clap(author, version, about)]
+pub struct CommandArgs
+{
+
+    /// subcommand
+    #[clap(subcommand)]
+    action: Action,
+
+    /// process id of parent shell
+    #[arg(long="pid")]
+    pid: u32,
+}
+
+#[derive(Debug, Clone, Subcommand)]
+pub enum Action
+{
+    /// navigate to path and add current path to the stack
+    push(PushArgs),
+
+    /// navigate to last entry in stack and remove it
+    pop(PopArgs),
+
+    /// display stack
+    stack(StackArgs),
+
+    // bookmark(BookmarkArgs),
+}
+
+#[derive(Debug, Clone, Args)]
+pub struct PushArgs
+{
+    /// show stack
+    show_stack: Option<bool>,
+
+    /// change to <path>
+    path: String,
+}
+
+#[derive(Debug, Clone, Args)]
+pub struct PopArgs
+{
+    /// show stack
+    #[arg(short, long)]
+    show_stack: Option<bool>,
+}
+
+#[derive(Debug, Clone, Args)]
+pub struct StackArgs
+{
+    /// hide entry numbers
+    #[arg(short, long)]
+    hide_numbers: Option<bool>,
+
+    /// show n entries
+    #[arg(short, long="lines")]
+    lines: Option<u32>,
+}

src/main.rs

@@ -1,20 +1,11 @@
+mod args;
+
 use std::env;
+use clap::Parser;
+use args::CommandArgs;
 
 
 fn main()
 {
-    let mut args : Vec<String> = env::args().collect();
+    let args = CommandArgs::parse();
-    let pid  : i32         = args[1].parse().unwrap();
-
-    // remove arguments which don't require parsing
-    args.remove(0); // remove command name
-    args.remove(0); // remove pid
-
-    for arg in args
-    {
-        if !(arg.clone().chars().nth(0).unwrap() == '-')
-        {
-            println!("{}", arg)
-        }
-    }    
 }