v0.2.11 : ligne de statut et banniere — compteurs distincts agents externes (PATH) et agents geres (am install) pour lever l ambiguite du 0 installed

Cargo.lock

@@ -21,7 +21,7 @@ dependencies = [
 
 [[package]]
 name = "agent-manager"
-version = "0.2.7"
+version = "0.2.11"
 dependencies = [
  "anyhow",
  "chrono",
@@ -41,6 +41,7 @@ dependencies = [
  "ureq",
  "wait-timeout",
  "which",
+ "windows-sys 0.52.0",
  "zip",
 ]
 

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "agent-manager"
-version = "0.2.7"
+version = "0.2.11"
 edition = "2021"
 description = "Manage local AI coding agents: list, install, start, stop, update — with automatic dependency handling and a YAML-driven catalog."
 license = "MIT"
@@ -35,6 +35,9 @@ wait-timeout = "0.2"
 which = "7"
 zip = "0.6"
 
+[target.'cfg(windows)'.dependencies]
+windows-sys = { version = "0.52", features = ["Win32_Foundation", "Win32_System_Threading", "Win32_System_ProcessStatus", "Win32_System_Diagnostics_ToolHelp", "Win32_System_Console"] }
+
 [profile.release]
 lto = "thin"
 strip = true

README.md

@@ -181,13 +181,24 @@ démarrage et mis en évidence** dans la bannière (config
 `settings.default_shell`, puis `SHELL`/`COMSPEC`, puis détection sur le
 PATH — pwsh, powershell, cmd, bash, zsh, fish, sh, nu, elvish).
 
-    ❯ ls                      # exécuté par le shell actif (cmd, pwsh, bash, ...)
+    ❯ ls                      # liste façon Nushell : tableau encadré (type, taille, date)
+    ❯ dir                     # sur Windows, même affichage que ls
+    ❯ ls src                  # un chemin précis — Tab complète fichiers et dossiers
+    ❯ ps                      # liste des processus (pid, ppid, cpu, mem, threads)
+    ❯ ls | where size > 1mb   # filtre la dernière table  (>, <, >=, <=, ==, !=, =~)
+    ❯ ps | where name =~ am   # =~ cherche dans le texte
+    ❯ ls | get name           # sélectionne une colonne
+    ❯ cd <Tab>                # complétion des dossiers uniquement, un niveau par Tab
     ❯ shell                   # affiche le shell courant + les shells disponibles
     ❯ shell bash              # change le shell de la session
-    ❯ !list                   # force l'exécution système (même nom qu'une commande am)
+    ❯ !ls · !list             # force l'exécution système (même nom qu'une commande am)
     ❯ cd ~/projets            # change le répertoire de la session (persistant)
     ❯ /help                   # commandes slash : /help · /version · /exit · /shell <nom>
 
+Le menu Tab affiche une **description** à côté de chaque candidat
+(commandes et agents), comme Nushell, et **cycle** entre les propositions à
+chaque Tab.
+
 Pour rendre le choix permanent : `settings.default_shell: pwsh` dans
 `config.yaml` (voir `am config path`).
 

src/lib.rs

@@ -20,13 +20,16 @@ pub mod deps;
 pub mod doctor;
 pub mod download;
 pub mod installers;
+pub mod nav;
 pub mod output;
 pub mod probe;
+pub mod ps;
 pub mod process;
 pub mod repl;
 pub mod runner;
 pub mod shell;
 pub mod state;
+pub mod tables;
 pub mod toolchain;
 pub mod version;
 

src/nav.rs

@@ -0,0 +1,312 @@
+//! Nushell-inspired navigation helpers: a boxed table listing of files and
+//! directories (ls), and directory/path completion for Tab.
+
+use crate::tables::{Cell, DataTable};
+use anyhow::{Context, Result};
+use colored::Colorize;
+use std::path::{Path, PathBuf};
+
+/// Human-readable byte size, like Nushell ("512 B", "1.2 KB", "3.4 MB").
+pub fn format_size(bytes: u64) -> String {
+    const KB: f64 = 1024.0;
+    const MB: f64 = 1024.0 * 1024.0;
+    const GB: f64 = 1024.0 * 1024.0 * 1024.0;
+    let b = bytes as f64;
+    if b < KB {
+        format!("{bytes} B")
+    } else if b < MB {
+        format!("{:.1} KB", b / KB)
+    } else if b < GB {
+        format!("{:.1} MB", b / MB)
+    } else {
+        format!("{:.1} GB", b / GB)
+    }
+}
+
+/// Recursive size of a directory, tightly bounded: beyond the entry cap the
+/// size is reported as unknown (None). The cap is deliberately small so a
+/// listing stays snappy even when it contains huge trees.
+pub fn dir_size(path: &Path) -> Option<u64> {
+    const CAP: usize = 500;
+    let mut total: u64 = 0;
+    let mut stack: Vec<PathBuf> = vec![path.to_path_buf()];
+    let mut visited: usize = 0;
+    while let Some(dir) = stack.pop() {
+        let rd = std::fs::read_dir(&dir).ok()?;
+        for entry in rd.flatten() {
+            visited += 1;
+            if visited > CAP {
+                return None;
+            }
+            let p = entry.path();
+            match std::fs::symlink_metadata(&p) {
+                Ok(m) if m.is_dir() => stack.push(p),
+                Ok(m) if m.is_file() => {
+                    total = total.saturating_add(m.len());
+                }
+                _ => {}
+            }
+        }
+    }
+    Some(total)
+}
+
+fn modified_str(path: &Path) -> String {
+    std::fs::metadata(path)
+        .and_then(|m| m.modified())
+        .ok()
+        .map(|t| {
+            let dt: chrono::DateTime<chrono::Local> = t.into();
+            dt.format("%Y-%m-%d %H:%M").to_string()
+        })
+        .unwrap_or_else(|| "—".to_string())
+}
+
+fn paint(s: &str, color: bool, style: u8) -> String {
+    if !color {
+        return s.to_string();
+    }
+    match style {
+        1 => s.blue().bold().to_string(),   // directory
+        2 => s.green().to_string(),         // executable
+        3 => s.cyan().to_string(),          // symlink
+        4 => s.red().to_string(),           // broken symlink
+        _ => s.to_string(),
+    }
+}
+
+fn is_executable(path: &Path, meta: &std::fs::Metadata) -> bool {
+    #[cfg(unix)]
+    {
+        use std::os::unix::fs::PermissionsExt;
+        meta.permissions().mode() & 0o111 != 0
+    }
+    #[cfg(windows)]
+    {
+        let _ = meta;
+        matches!(
+            path.extension()
+                .and_then(|e| e.to_str())
+                .map(|e| e.to_lowercase())
+                .as_deref(),
+            Some("exe") | Some("bat") | Some("cmd") | Some("com")
+        )
+    }
+}
+
+/// Build the ls table (columns: name, type, size, modified). Directories
+/// come first, then alphabetical order.
+pub fn ls_table(path: &Path, color: bool) -> Result<DataTable> {
+    let rd = std::fs::read_dir(path)
+        .with_context(|| format!("cannot read {}", path.display()))?;
+    let mut rows: Vec<(String, Vec<Cell>)> = Vec::new();
+    for entry in rd.flatten() {
+        let p = entry.path();
+        let meta = match std::fs::symlink_metadata(&p) {
+            Ok(m) => m,
+            Err(_) => continue,
+        };
+        let file_type = meta.file_type();
+        let name = p
+            .file_name()
+            .map(|n| n.to_string_lossy().to_string())
+            .unwrap_or_default();
+        let (kind, style) = if file_type.is_symlink() {
+            ("symlink", if p.exists() { 3 } else { 4 })
+        } else if file_type.is_dir() {
+            ("dir", 1)
+        } else if is_executable(&p, &meta) {
+            ("file", 2)
+        } else {
+            ("file", 0)
+        };
+        let (size_text, size_bytes) = if file_type.is_dir() {
+            match dir_size(&p) {
+                Some(s) => (format_size(s), Some(s)),
+                None => ("—".to_string(), None),
+            }
+        } else {
+            (format_size(meta.len()), Some(meta.len()))
+        };
+        let mut display = name.clone();
+        if file_type.is_dir() {
+            display.push('/');
+        } else if file_type.is_symlink() {
+            if let Ok(target) = std::fs::read_link(&p) {
+                display.push_str(&format!(" -> {}", target.display()));
+            }
+        }
+        rows.push((
+            name.to_lowercase(),
+            vec![
+                Cell::str(paint(&display, color, style)),
+                Cell::str(kind.to_string()),
+                Cell::bytes(size_bytes.unwrap_or(0), size_text),
+                Cell::str(modified_str(&p)),
+            ],
+        ));
+    }
+    // Directories first, then alphabetical.
+    rows.sort_by(|a, b| {
+        let a_dir = a.1[1].text == "dir";
+        let b_dir = b.1[1].text == "dir";
+        b_dir.cmp(&a_dir).then_with(|| a.0.cmp(&b.0))
+    });
+    Ok(DataTable {
+        columns: vec![
+            "name".into(),
+            "type".into(),
+            "size".into(),
+            "modified".into(),
+        ],
+        rows: rows.into_iter().map(|(_, r)| r).collect(),
+    })
+}
+
+/// Render a Nushell-style boxed table of the entries of a path (unbounded
+/// width — used by tests; the REPL renders with the terminal width).
+pub fn render_ls(path: &Path, color: bool) -> Result<String> {
+    Ok(ls_table(path, color)?.render(color, 200))
+}
+
+/// Completion candidates for a path fragment typed after cd or ls.
+///
+/// The last segment is matched against the entries of the base directory;
+/// directory candidates end with a separator so the next Tab dives one level
+/// deeper, like Nushell. With dirs_only, files are excluded (cd).
+pub fn path_candidates(base_dir: &Path, input: &str, dirs_only: bool) -> Vec<String> {
+    let sep = std::path::MAIN_SEPARATOR;
+    let alt = if sep == '\\' { '/' } else { '\\' };
+    let idx = input.rfind(|c| c == sep || c == alt);
+    let (base_part, stem) = match idx {
+        Some(i) => (&input[..=i], &input[i + 1..]),
+        None => ("", input),
+    };
+    let use_sep = if input.contains(alt) && !input.contains(sep) {
+        alt
+    } else {
+        sep
+    };
+    let base: PathBuf = if base_part.starts_with('~') {
+        crate::config::expand_path(base_part)
+    } else if base_part.is_empty() {
+        base_dir.to_path_buf()
+    } else {
+        PathBuf::from(base_part)
+    };
+
+    let mut names: Vec<(String, bool)> = Vec::new();
+    if let Ok(rd) = std::fs::read_dir(&base) {
+        for entry in rd.flatten() {
+            let p = entry.path();
+            let is_dir = p.is_dir();
+            if dirs_only && !is_dir {
+                continue;
+            }
+            let Some(name) = p.file_name().and_then(|n| n.to_str()) else {
+                continue;
+            };
+            if !name.starts_with(stem) {
+                continue;
+            }
+            names.push((name.to_string(), is_dir));
+        }
+    }
+    names.sort_by(|a, b| {
+        b.1.cmp(&a.1)
+            .then_with(|| a.0.to_lowercase().cmp(&b.0.to_lowercase()))
+    });
+    names
+        .into_iter()
+        .map(|(name, is_dir)| {
+            let mut full = format!("{base_part}{name}");
+            if is_dir {
+                full.push(use_sep);
+            }
+            full
+        })
+        .collect()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn formats_sizes() {
+        assert_eq!(format_size(0), "0 B");
+        assert_eq!(format_size(512), "512 B");
+        assert_eq!(format_size(2048), "2.0 KB");
+        assert_eq!(format_size(5 * 1024 * 1024), "5.0 MB");
+        assert_eq!(format_size(3 * 1024 * 1024 * 1024), "3.0 GB");
+    }
+
+    #[test]
+    fn dir_size_is_bounded() {
+        let dir = tempfile::tempdir().unwrap();
+        let big = dir.path().join("big");
+        std::fs::create_dir_all(&big).unwrap();
+        for i in 0..520 {
+            std::fs::write(big.join(format!("f{i}.txt")), "x").unwrap();
+        }
+        // Beyond the cap the size is unknown, and the walk stays cheap.
+        assert_eq!(dir_size(&big), None);
+        let small = dir.path().join("small");
+        std::fs::create_dir_all(&small).unwrap();
+        std::fs::write(small.join("a.txt"), "hello").unwrap();
+        assert_eq!(dir_size(&small), Some(5));
+    }
+
+    #[test]
+    fn completes_directories_only() {
+        let dir = tempfile::tempdir().unwrap();
+        std::fs::create_dir_all(dir.path().join("src")).unwrap();
+        std::fs::create_dir_all(dir.path().join("src2")).unwrap();
+        std::fs::write(dir.path().join("readme.txt"), "x").unwrap();
+
+        let cands = path_candidates(dir.path(), "", true);
+        assert!(cands.iter().any(|c| c == "src\\" || c == "src/"));
+        assert!(cands.iter().any(|c| c == "src2\\" || c == "src2/"));
+        assert!(!cands.iter().any(|c| c.contains("readme")));
+
+        let cands = path_candidates(dir.path(), "s", true);
+        assert_eq!(cands.len(), 2, "{cands:?}");
+
+        // Files appear for ls completion.
+        let cands = path_candidates(dir.path(), "", false);
+        assert!(cands.iter().any(|c| c.contains("readme")));
+    }
+
+    #[test]
+    fn completes_nested_paths() {
+        let dir = tempfile::tempdir().unwrap();
+        std::fs::create_dir_all(dir.path().join("src").join("commands")).unwrap();
+        std::fs::create_dir_all(dir.path().join("src").join("installers")).unwrap();
+        let sep = std::path::MAIN_SEPARATOR;
+        let prefix = format!("src{}", sep);
+        let cands = path_candidates(dir.path(), &format!("src{}co", sep), true);
+        assert!(cands.iter().any(|c| c == &format!("{prefix}commands{}", sep)));
+        assert!(!cands.iter().any(|c| c.contains("installers")));
+    }
+
+    #[test]
+    fn renders_ls_table() {
+        let dir = tempfile::tempdir().unwrap();
+        std::fs::create_dir_all(dir.path().join("subdir")).unwrap();
+        std::fs::write(dir.path().join("file.txt"), "hello").unwrap();
+        let table = render_ls(dir.path(), false).unwrap();
+        assert!(table.contains("╭"));
+        assert!(table.contains("╰"));
+        assert!(table.contains("name"));
+        assert!(table.contains("type"));
+        assert!(table.contains("modified"));
+        assert!(table.contains("subdir/"));
+        assert!(table.contains("file.txt"));
+        assert!(table.contains("dir"));
+        assert!(table.contains("file"));
+        assert!(table.contains("5 B"));
+        // Every line of the table has the same width.
+        let widths: Vec<usize> = table.lines().map(|l| l.chars().count()).collect();
+        assert!(widths.iter().all(|w| *w == widths[0]), "unaligned table:\n{table}");
+    }
+}

src/output.rs

@@ -239,6 +239,42 @@ pub fn print_json<T: Serialize>(value: &T) {
     }
 }
 
+/// Width of the terminal attached to stdout, in columns. Returns None when
+/// stdout is not a terminal (e.g. piped). AM_TABLE_WIDTH overrides it, mostly
+/// for tests and scripts.
+pub fn terminal_width() -> Option<usize> {
+    if let Ok(v) = std::env::var("AM_TABLE_WIDTH") {
+        if let Ok(w) = v.trim().parse::<usize>() {
+            return Some(w);
+        }
+    }
+    #[cfg(windows)]
+    {
+        use std::os::windows::io::AsRawHandle;
+        use windows_sys::Win32::System::Console::{
+            GetConsoleScreenBufferInfo, CONSOLE_SCREEN_BUFFER_INFO,
+        };
+        let handle = std::io::stdout().as_raw_handle() as isize;
+        let mut info: CONSOLE_SCREEN_BUFFER_INFO = unsafe { std::mem::zeroed() };
+        if unsafe { GetConsoleScreenBufferInfo(handle, &mut info) } != 0 {
+            let width = (info.srWindow.Right - info.srWindow.Left + 1) as usize;
+            if width > 0 {
+                return Some(width);
+            }
+        }
+        None
+    }
+    #[cfg(not(windows))]
+    {
+        if let Ok(v) = std::env::var("COLUMNS") {
+            if let Ok(w) = v.trim().parse::<usize>() {
+                return Some(w);
+            }
+        }
+        None
+    }
+}
+
 fn strip_ansi(s: &str) -> String {
     let mut out = String::new();
     let mut chars = s.chars();

src/ps.rs

@@ -0,0 +1,218 @@
+//! ps: Nushell-style process table.
+//!
+//! Windows uses the Toolhelp32 snapshot API (pid, ppid, name, threads, cpu
+//! time, working set); Unix reads /proc.
+
+use crate::tables::{Cell, DataTable};
+
+/// Columns: pid, ppid, name, cpu, mem, threads.
+fn columns() -> Vec<String> {
+    vec![
+        "pid".into(),
+        "ppid".into(),
+        "name".into(),
+        "cpu".into(),
+        "mem".into(),
+        "threads".into(),
+    ]
+}
+
+/// Build the process table.
+pub fn ps_table() -> DataTable {
+    #[cfg(windows)]
+    let rows = windows_rows();
+    #[cfg(unix)]
+    let rows = unix_rows();
+    #[cfg(not(any(windows, unix)))]
+    let rows = Vec::new();
+
+    let mut rows = rows;
+    rows.sort_by(|a, b| {
+        a[0]
+            .num
+            .unwrap_or(0.0)
+            .partial_cmp(&b[0].num.unwrap_or(0.0))
+            .unwrap_or(std::cmp::Ordering::Equal)
+    });
+    DataTable {
+        columns: columns(),
+        rows,
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Windows: Toolhelp32 snapshot
+// ---------------------------------------------------------------------------
+
+#[cfg(windows)]
+fn windows_rows() -> Vec<Vec<Cell>> {
+    use crate::nav::format_size;
+    use std::mem::size_of;
+    use windows_sys::Win32::Foundation::{CloseHandle, INVALID_HANDLE_VALUE};
+    use windows_sys::Win32::System::Diagnostics::ToolHelp::{
+        CreateToolhelp32Snapshot, Process32FirstW, Process32NextW, PROCESSENTRY32W,
+        TH32CS_SNAPPROCESS,
+    };
+    use windows_sys::Win32::System::ProcessStatus::{
+        K32GetProcessMemoryInfo, PROCESS_MEMORY_COUNTERS,
+    };
+    use windows_sys::Win32::System::Threading::{
+        GetProcessTimes, OpenProcess, PROCESS_QUERY_INFORMATION,
+    };
+
+    let mut rows: Vec<Vec<Cell>> = Vec::new();
+    let snapshot = unsafe { CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0) };
+    if snapshot == INVALID_HANDLE_VALUE {
+        return rows;
+    }
+    let mut entry: PROCESSENTRY32W = unsafe { std::mem::zeroed() };
+    entry.dwSize = size_of::<PROCESSENTRY32W>() as u32;
+    let mut ok = unsafe { Process32FirstW(snapshot, &mut entry) };
+    while ok != 0 {
+        let pid = entry.th32ProcessID;
+        let ppid = entry.th32ParentProcessID;
+        let threads = entry.cntThreads;
+        let mut name = String::new();
+        for &unit in entry.szExeFile.iter() {
+            if unit == 0 {
+                break;
+            }
+            if let Some(c) = char::from_u32(unit as u32) {
+                name.push(c);
+            }
+        }
+
+        // CPU time and memory need a process handle; some system processes
+        // refuse — those cells stay "—".
+        let mut cpu = "—".to_string();
+        let mut mem = "—".to_string();
+        let handle = unsafe { OpenProcess(PROCESS_QUERY_INFORMATION, 0, pid) };
+        if handle != 0 {
+            let mut counters: PROCESS_MEMORY_COUNTERS = unsafe { std::mem::zeroed() };
+            if unsafe {
+                K32GetProcessMemoryInfo(
+                    handle,
+                    &mut counters,
+                    size_of::<PROCESS_MEMORY_COUNTERS>() as u32,
+                )
+            } != 0
+            {
+                mem = format_size(counters.WorkingSetSize as u64);
+            }
+            let (mut created, mut exited, mut kernel, mut user): (
+                windows_sys::Win32::Foundation::FILETIME,
+                windows_sys::Win32::Foundation::FILETIME,
+                windows_sys::Win32::Foundation::FILETIME,
+                windows_sys::Win32::Foundation::FILETIME,
+            ) = unsafe {
+                (
+                    std::mem::zeroed(),
+                    std::mem::zeroed(),
+                    std::mem::zeroed(),
+                    std::mem::zeroed(),
+                )
+            };
+            if unsafe { GetProcessTimes(handle, &mut created, &mut exited, &mut kernel, &mut user) } != 0 {
+                let ticks = (filetime_u64(&kernel) + filetime_u64(&user)) as f64 / 10_000_000.0;
+                cpu = format!("{ticks:.0}s");
+            }
+            unsafe { CloseHandle(handle) };
+        }
+
+        rows.push(vec![
+            Cell::num(pid as f64, pid.to_string()),
+            Cell::num(ppid as f64, ppid.to_string()),
+            Cell::str(name),
+            Cell::str(cpu),
+            Cell::str(mem),
+            Cell::num(threads as f64, threads.to_string()),
+        ]);
+        ok = unsafe { Process32NextW(snapshot, &mut entry) };
+    }
+    unsafe { CloseHandle(snapshot) };
+    rows
+}
+
+#[cfg(windows)]
+fn filetime_u64(ft: &windows_sys::Win32::Foundation::FILETIME) -> u64 {
+    ((ft.dwHighDateTime as u64) << 32) | (ft.dwLowDateTime as u64)
+}
+
+// ---------------------------------------------------------------------------
+// Unix: /proc
+// ---------------------------------------------------------------------------
+
+#[cfg(unix)]
+fn unix_rows() -> Vec<Vec<Cell>> {
+    use crate::nav::format_size;
+    let page_size = page_size();
+    let mut rows: Vec<Vec<Cell>> = Vec::new();
+    let Ok(entries) = std::fs::read_dir("/proc") else {
+        return rows;
+    };
+    for entry in entries.flatten() {
+        let name = entry.file_name().to_string_lossy().to_string();
+        let Ok(pid) = name.parse::<f64>() else {
+            continue;
+        };
+        let base = entry.path();
+        let Ok(stat) = std::fs::read_to_string(base.join("stat")) else {
+            continue;
+        };
+        // The comm field is in parentheses and may contain spaces.
+        let Some(close) = stat.rfind(')') else {
+            continue;
+        };
+        let comm = stat[stat.find('(').unwrap_or(0) + 1..close].to_string();
+        let rest: Vec<&str> = stat[close + 2..].split_whitespace().collect();
+        if rest.len() < 22 {
+            continue;
+        }
+        // rest[0]=state, rest[1]=ppid, rest[11]=utime, rest[12]=stime,
+        // rest[17]=num_threads, rest[21]=rss (pages).
+        let ppid = rest[1].parse::<f64>().unwrap_or(0.0);
+        let utime = rest[11].parse::<f64>().unwrap_or(0.0);
+        let stime = rest[12].parse::<f64>().unwrap_or(0.0);
+        let threads = rest[17].parse::<f64>().unwrap_or(0.0);
+        let rss_pages = rest[21].parse::<u64>().unwrap_or(0);
+        let cpu = (utime + stime) / 100.0;
+        rows.push(vec![
+            Cell::num(pid, pid.to_string()),
+            Cell::num(ppid, ppid.to_string()),
+            Cell::str(comm),
+            Cell::str(format!("{cpu:.0}s")),
+            Cell::str(format_size(rss_pages * page_size)),
+            Cell::num(threads, threads.to_string()),
+        ]);
+    }
+    rows
+}
+
+#[cfg(unix)]
+fn page_size() -> u64 {
+    // Standard page size; RSS in pages * 4096 is close enough for display.
+    4096
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn ps_produces_a_table() {
+        let table = ps_table();
+        assert_eq!(
+            table.columns,
+            vec!["pid", "ppid", "name", "cpu", "mem", "threads"]
+        );
+        assert!(!table.rows.is_empty(), "process table should not be empty");
+        // Our own pid is in the table.
+        let me = std::process::id().to_string();
+        assert!(
+            table.rows.iter().any(|r| r[0].text == me),
+            "our pid should be listed"
+        );
+        // Rows have as many cells as columns.
+        assert!(table.rows.iter().all(|r| r.len() == 6));
+    }
+}

src/repl.rs

@@ -15,6 +15,9 @@
 use crate::app::App;
 use crate::cli::{Cli, Command, StartArgs};
 use crate::commands;
+use crate::nav;
+use crate::ps;
+use crate::tables::DataTable;
 use crate::shell::ShellSession;
 use anyhow::{anyhow, Result};
 use clap::CommandFactory;
@@ -44,8 +47,43 @@ pub struct AmCompleter {
     agents: Vec<String>,
     aliases: Vec<String>,
     groups: Vec<String>,
+    /// Short descriptions shown next to candidates in the Tab menu
+    /// (Nushell-style).
+    descriptions: BTreeMap<String, String>,
 }
 
+/// One-line descriptions for the Tab completion menu.
+const COMMAND_DESCRIPTIONS: &[(&str, &str)] = &[
+    ("list", "list installed agents"),
+    ("status", "show agent state"),
+    ("search", "search the catalog"),
+    ("info", "agent details"),
+    ("install", "install an agent"),
+    ("uninstall", "remove an agent"),
+    ("update", "update agents"),
+    ("start", "start an agent"),
+    ("stop", "stop an agent"),
+    ("restart", "restart an agent"),
+    ("run", "run an agent command"),
+    ("doctor", "check the environment"),
+    ("config", "manage the configuration"),
+    ("completion", "generate a completion script"),
+    ("self-update", "update agent-manager"),
+    ("self-uninstall", "remove agent-manager"),
+    ("export", "backup config + state"),
+    ("import", "restore a backup"),
+    ("shell", "show or switch the system shell"),
+    ("ls", "list files and directories (Nushell-style)"),
+    ("dir", "list files and directories (same as ls)"),
+    ("cd", "change directory — Tab completes folders"),
+    ("ps", "list processes"),
+    ("where", "filter the last table — where size > 1mb"),
+    ("get", "select a column — get name"),
+    ("help", "show this help"),
+    ("version", "print the version"),
+    ("exit", "quit the shell"),
+];
+
 impl AmCompleter {
     pub fn new(app: &App) -> Self {
         Self::from_catalog(&app.catalog, &app.config.aliases, &app.config.groups)
@@ -67,12 +105,27 @@ impl AmCompleter {
         alias_list.sort();
         let mut group_list: Vec<String> = groups.keys().map(|g| format!("group:{g}")).collect();
         group_list.sort();
+        let mut descriptions: BTreeMap<String, String> = BTreeMap::new();
+        for (cmd, desc) in COMMAND_DESCRIPTIONS {
+            descriptions.insert((*cmd).to_string(), (*desc).to_string());
+        }
+        for a in catalog.agents() {
+            if a.hidden {
+                continue;
+            }
+            let desc = a
+                .category
+                .clone()
+                .or_else(|| a.description.clone())
+                .unwrap_or_default();
+            descriptions.insert(a.name.clone(), truncate_desc(&desc));
+        }
         Self {
             commands: vec![
                 "list", "status", "search", "info", "install", "uninstall", "update",
                 "start", "stop", "restart", "run", "doctor", "config", "completion",
-                "self-update", "self-uninstall", "export", "import", "shell", "help",
-                "version", "exit",
+                "self-update", "self-uninstall", "export", "import", "shell", "ls", "dir",
+                "cd", "ps", "where", "get", "help", "version", "exit",
             ],
             config_sub: vec!["show", "path", "edit", "validate", "add"],
             shells: vec!["bash", "zsh", "fish", "powershell", "elvish"],
@@ -88,6 +141,7 @@ impl AmCompleter {
             agents,
             aliases: alias_list,
             groups: group_list,
+            descriptions,
         }
     }
 
@@ -118,6 +172,16 @@ impl AmCompleter {
                 "shell" => {
                     pool = self.gateway_shells.iter().map(|s| s.to_string()).collect();
                 }
+                "cd" | "chdir" => {
+                    // Complete directories only — dive one level per Tab.
+                    let cwd = current_dir();
+                    pool = crate::nav::path_candidates(&cwd, word, true);
+                }
+                "ls" | "dir" => {
+                    // Complete paths (files and directories).
+                    let cwd = current_dir();
+                    pool = crate::nav::path_candidates(&cwd, word, false);
+                }
                 "install" | "uninstall" | "update" | "start" | "stop" | "restart" | "run"
                 | "info" | "status" => {
                     if word.starts_with("group:") {
@@ -136,6 +200,11 @@ impl AmCompleter {
                 _ => {
                     if word.starts_with('-') {
                         pool = self.options.iter().map(|s| s.to_string()).collect();
+                    } else {
+                        // Nushell fallback: complete file paths for external
+                        // (system) commands when nothing else applies.
+                        let cwd = current_dir();
+                        pool = crate::nav::path_candidates(&cwd, word, false);
                     }
                 }
             }
@@ -172,9 +241,17 @@ impl Completer for AmCompleter {
         let (start, cands) = self.candidates_for(line, pos);
         let pairs = cands
             .into_iter()
-            .map(|c| Pair {
-                display: c.clone(),
-                replacement: c,
+            .map(|c| {
+                // Nushell-style menu: show a description next to the
+                // candidate when one is known.
+                let display = match self.descriptions.get(&c) {
+                    Some(d) if !d.is_empty() => format!("{c}\t{d}"),
+                    _ => c.clone(),
+                };
+                Pair {
+                    display,
+                    replacement: c,
+                }
             })
             .collect();
         Ok((start, pairs))
@@ -277,6 +354,7 @@ pub fn banner_box(
     version: &str,
     agents: usize,
     installed: usize,
+    external: usize,
     session: &ShellSession,
     session_id: &str,
     cwd: &str,
@@ -340,13 +418,15 @@ pub fn banner_box(
         "  system     doctor · config · completion · self-update · self-uninstall · export · import"
             .to_string(),
     ));
-    rows.push(inner("  shell      shell · help · version · exit".to_string()));
+    rows.push(inner(
+        "  shell      ls · cd · ps · where · get · shell · help · version · exit".to_string(),
+    ));
 
     // Stats footer.
     rows.push(blank());
     rows.push(inner(dim(
         &format!(
-            "am v{version} · {agents} agents · {installed} installed · shell {} · /help for commands",
+            "am v{version} · {agents} agents · {external} external · {installed} managed · shell {} · /help for commands",
             session.current.name
         ),
         color,
@@ -370,6 +450,7 @@ pub fn banner(app: &App, session: &ShellSession, session_id: &str) -> String {
         env!("CARGO_PKG_VERSION"),
         agent_count(app),
         installed_count(app),
+        external_count(app),
         session,
         session_id,
         &current_dir_string(),
@@ -405,8 +486,9 @@ fn print_status(app: &App, session: &ShellSession, started: Instant) {
     );
     let counts = dim(
         &format!(
-            "{} agents · {} installed",
+            "{} agents · {} external · {} managed",
             agent_count(app),
+            external_count(app),
             installed_count(app)
         ),
         color,
@@ -530,12 +612,45 @@ fn installed_count(app: &App) -> usize {
         .unwrap_or(0)
 }
 
+/// Number of external agents (installed outside agent-manager) detected on
+/// the PATH — the same definition used by the "external" status in am list.
+fn external_count(app: &App) -> usize {
+    let probe = crate::probe::detect_externals(app);
+    let managed: std::collections::BTreeSet<String> = app
+        .state
+        .load()
+        .ok()
+        .map(|s| s.installed.keys().cloned().collect())
+        .unwrap_or_default();
+    app.catalog
+        .agents()
+        .iter()
+        .filter(|a| !a.hidden && a.installable)
+        .filter(|a| !managed.contains(&a.name))
+        .filter(|a| probe.path_of(&a.name).is_some())
+        .count()
+}
+
 fn current_dir_string() -> String {
     std::env::current_dir()
         .map(|p| p.display().to_string())
         .unwrap_or_else(|_| "?".to_string())
 }
 
+fn current_dir() -> PathBuf {
+    std::env::current_dir().unwrap_or_else(|_| PathBuf::from("."))
+}
+
+/// Keep a catalog description short enough for the completion menu.
+fn truncate_desc(desc: &str) -> String {
+    let one_line = desc.lines().next().unwrap_or(desc);
+    let mut out: String = one_line.chars().take(64).collect();
+    if one_line.chars().count() > 64 {
+        out.push('…');
+    }
+    out
+}
+
 // ---------------------------------------------------------------------------
 // Interactive loop
 // ---------------------------------------------------------------------------
@@ -568,11 +683,17 @@ fn run_with_editor(app: &App, session: &mut ShellSession) -> Result<i32> {
     let mut rl: rustyline::Editor<AmCompleter, rustyline::history::FileHistory> =
         rustyline::Editor::new()?;
     rl.set_helper(Some(AmCompleter::new(app)));
+    // Nushell-style completion: a single match is inserted immediately;
+    // otherwise Tab inserts the longest common prefix and the menu lists the
+    // candidates with their descriptions.
+    use rustyline::config::{CompletionType, Configurer};
+    let _ = rl.set_completion_type(CompletionType::List);
     let history_path = app.paths.state_file.with_file_name("history.txt");
     if rl.load_history(&history_path).is_err() {
         // First run: no history yet.
     }
     let started = Instant::now();
+    let mut last: Option<DataTable> = None;
     loop {
         print_status(app, session, started);
         match rl.readline("❯ ") {
@@ -582,7 +703,7 @@ fn run_with_editor(app: &App, session: &mut ShellSession) -> Result<i32> {
                     continue;
                 }
                 let _ = rl.add_history_entry(trimmed.as_str());
-                match handle_input(app, session, &trimmed) {
+                match handle_input(app, session, &mut last, &trimmed) {
                     Ok(true) => break,
                     Ok(false) => {}
                     Err(e) => app.log.error(&format!("{e:#}")),
@@ -603,6 +724,7 @@ fn run_with_editor(app: &App, session: &mut ShellSession) -> Result<i32> {
 /// Plain fallback when no terminal/line editor is available.
 fn run_plain(app: &App, session: &mut ShellSession) -> Result<i32> {
     let started = Instant::now();
+    let mut last: Option<DataTable> = None;
     loop {
         print_status(app, session, started);
         eprint!("❯ ");
@@ -615,7 +737,7 @@ fn run_plain(app: &App, session: &mut ShellSession) -> Result<i32> {
         if line.is_empty() {
             continue;
         }
-        match handle_input(app, session, &line) {
+        match handle_input(app, session, &mut last, &line) {
             Ok(true) => break,
             Ok(false) => {}
             Err(e) => app.log.error(&format!("{e:#}")),
@@ -625,7 +747,12 @@ fn run_plain(app: &App, session: &mut ShellSession) -> Result<i32> {
 }
 
 /// Handle one line of input. Returns true when the session should exit.
-fn handle_input(app: &App, session: &mut ShellSession, line: &str) -> Result<bool> {
+fn handle_input(
+    app: &App,
+    session: &mut ShellSession,
+    last: &mut Option<DataTable>,
+    line: &str,
+) -> Result<bool> {
     match line {
         "exit" | "quit" | "q" | "/exit" | "/quit" => return Ok(true),
         "help" | "?" | "/help" => {
@@ -652,12 +779,21 @@ fn handle_input(app: &App, session: &mut ShellSession, line: &str) -> Result<boo
         }
         return Ok(false);
     }
-    handle_line(app, session, line)
+    handle_line(app, session, last, line)
 }
 
 /// Handle one line of input. Returns true when the session should exit
 /// (only after a successful self-uninstall: the binary is gone).
-fn handle_line(app: &App, session: &mut ShellSession, line: &str) -> Result<bool> {
+fn handle_line(
+    app: &App,
+    session: &mut ShellSession,
+    last: &mut Option<DataTable>,
+    line: &str,
+) -> Result<bool> {
+    // Nushell-style pipelines: ls | where ... | get ...
+    if line.contains('|') {
+        return eval_pipeline(app, last, line);
+    }
     // '!' forces system execution even for words that look like am commands.
     if let Some(rest) = line.strip_prefix('!') {
         let rest = rest.trim();
@@ -682,6 +818,40 @@ fn handle_line(app: &App, session: &mut ShellSession, line: &str) -> Result<bool
         shell_command(session, rest.first().map(|s| s.as_str()));
         return Ok(false);
     }
+    // Nushell-style directory listing (the system ls stays available as !ls,
+    // and dir maps to the same table on Windows).
+    if cmd == "ls" || (cmd == "dir" && cfg!(windows)) {
+        let table = nav::ls_table(&ls_target(rest)?, app.color())?;
+        show_table(app, last, table);
+        return Ok(false);
+    }
+    if cmd == "ps" {
+        show_table(app, last, ps::ps_table());
+        return Ok(false);
+    }
+    if cmd == "where" {
+        let base = last
+            .clone()
+            .ok_or_else(|| anyhow!("'where' needs a table — run ls or ps first (e.g. ls | where size > 1mb)"))?;
+        if rest.len() < 3 {
+            anyhow::bail!("usage: where <column> <op> <value>");
+        }
+        let filtered =
+            crate::tables::filter_where(&base, &rest[0], &rest[1], &rest[2..].join(" "))?;
+        show_table(app, last, filtered);
+        return Ok(false);
+    }
+    if cmd == "get" {
+        let base = last
+            .clone()
+            .ok_or_else(|| anyhow!("'get' needs a table — run ls or ps first (e.g. ls | get name)"))?;
+        let field = rest
+            .first()
+            .ok_or_else(|| anyhow!("usage: get <column>"))?;
+        let column = crate::tables::get_column(&base, field)?;
+        show_table(app, last, column);
+        return Ok(false);
+    }
     // Everything that is not an am command is a system command.
     if !is_am_command(cmd) {
         run_system(app, session, line)?;
@@ -825,6 +995,80 @@ fn is_am_command(word: &str) -> bool {
     )
 }
 
+/// Resolve the path argument of ls/dir (defaults to the current directory).
+fn ls_target(rest: &[String]) -> Result<std::path::PathBuf> {
+    Ok(match rest.first() {
+        Some(p) => crate::config::expand_path(p),
+        None => current_dir(),
+    })
+}
+
+/// Print a table and remember it as the last result (for where/get).
+/// The table is rendered to fit the terminal width so rows never wrap.
+fn show_table(app: &App, last: &mut Option<DataTable>, table: DataTable) {
+    let width = crate::output::terminal_width().unwrap_or(120);
+    print!("{}", table.render(app.color(), width));
+    *last = Some(table);
+}
+
+/// Evaluate a Nushell-style pipeline: ls | ps | where | get, in order.
+fn eval_pipeline(app: &App, last: &mut Option<DataTable>, line: &str) -> Result<bool> {
+    let parts: Vec<&str> = line
+        .split('|')
+        .map(str::trim)
+        .filter(|p| !p.is_empty())
+        .collect();
+    let mut table: Option<DataTable> = None;
+    for part in &parts {
+        let tokens =
+            shell_words::split(part).map_err(|e| anyhow!("cannot parse command: {e}"))?;
+        if tokens.is_empty() {
+            continue;
+        }
+        let cmd = tokens[0].as_str();
+        let rest = &tokens[1..];
+        match cmd {
+            "ls" => {
+                table = Some(nav::ls_table(&ls_target(rest)?, app.color())?);
+            }
+            "dir" if cfg!(windows) => {
+                table = Some(nav::ls_table(&ls_target(rest)?, app.color())?);
+            }
+            "ps" => {
+                table = Some(ps::ps_table());
+            }
+            "where" => {
+                let base = table
+                    .as_ref()
+                    .ok_or_else(|| anyhow!("'where' needs a table before it"))?;
+                if rest.len() < 3 {
+                    anyhow::bail!("usage: where <column> <op> <value>");
+                }
+                table = Some(crate::tables::filter_where(
+                    base,
+                    &rest[0],
+                    &rest[1],
+                    &rest[2..].join(" "),
+                )?);
+            }
+            "get" => {
+                let base = table
+                    .as_ref()
+                    .ok_or_else(|| anyhow!("'get' needs a table before it"))?;
+                let field = rest.first().ok_or_else(|| anyhow!("usage: get <column>"))?;
+                table = Some(crate::tables::get_column(base, field)?);
+            }
+            other => anyhow::bail!(
+                "'{other}' cannot be used in a pipeline — use ls, ps, where or get"
+            ),
+        }
+    }
+    if let Some(t) = table {
+        show_table(app, last, t);
+    }
+    Ok(false)
+}
+
 /// Run one system command through the active shell (inherited stdio).
 fn run_system(app: &App, session: &ShellSession, line: &str) -> Result<()> {
     app.log.cmd(&format!("{}: {line}", session.current.name));
@@ -904,12 +1148,21 @@ fn print_help() {
     println!("  export [--output FILE]          backup config + state");
     println!("  import <file>                   restore a backup");
     println!("  shell [list|<name>]             show or switch the system shell");
+    println!("  ls [path] · dir [path]         list files and directories (Nushell-style table)");
+    println!("  ps                               list processes");
+    println!("  where <col> <op> <val>          filter the last table  (ls | where size > 1mb)");
+    println!("  get <col>                       select a column        (ls | get name)");
+    println!("  cd <dir>                        change directory — Tab completes folders");
     println!("  help | version | exit           this help, the version, quit");
     println!();
+    println!("pipelines:");
+    println!("  ls | where size > 1mb | get name");
+    println!("  ps | where name =~ am");
+    println!();
     println!("system gateway:");
     println!("  any other input runs as a system command in the active shell");
-    println!("  prefix with '!' to force system execution (e.g. '!list')");
-    println!("  'cd <dir>' changes the session directory (in-process)");
+    println!("  prefix with '!' to force system execution (e.g. '!ls', '!list')");
+    println!("  Tab inserts the common prefix and lists candidates with descriptions");
     println!();
     println!("slash commands: /help · /version · /exit · /shell <name>");
 }
@@ -1014,6 +1267,7 @@ mod tests {
             "9.9.9",
             65,
             3,
+            12,
             &session,
             "20260815_123456_abcdef",
             "/home/alice/dev/agent-manager",
@@ -1027,6 +1281,8 @@ mod tests {
         assert!(text.contains("(default)"));
         assert!(text.contains("bash"));
         assert!(text.contains("/help for commands"));
+        assert!(text.contains("12 external"));
+        assert!(text.contains("3 managed"));
         assert!(text.contains("agent-manager"));
     }
 

src/tables.rs

@@ -0,0 +1,425 @@
+//! Generic Nushell-style tables: render a boxed table, filter rows with
+//! where-like predicates and select a column with get.
+
+use anyhow::{bail, Result};
+use colored::Colorize;
+
+/// One cell: the text to display plus a typed value for filtering
+/// (number, byte size, or plain string).
+#[derive(Debug, Clone)]
+pub struct Cell {
+    pub text: String,
+    pub num: Option<f64>,
+    pub bytes: Option<u64>,
+}
+
+impl Cell {
+    pub fn str(s: impl Into<String>) -> Self {
+        Cell {
+            text: s.into(),
+            num: None,
+            bytes: None,
+        }
+    }
+
+    pub fn num(n: f64, text: String) -> Self {
+        Cell {
+            text,
+            num: Some(n),
+            bytes: None,
+        }
+    }
+
+    pub fn bytes(b: u64, text: String) -> Self {
+        Cell {
+            text,
+            num: None,
+            bytes: Some(b),
+        }
+    }
+}
+
+/// A tabular result produced by ls, ps, where or get.
+#[derive(Debug, Clone, Default)]
+pub struct DataTable {
+    pub columns: Vec<String>,
+    pub rows: Vec<Vec<Cell>>,
+}
+
+impl DataTable {
+    pub fn column_index(&self, name: &str) -> Option<usize> {
+        self.columns
+            .iter()
+            .position(|c| c.eq_ignore_ascii_case(name))
+    }
+
+    /// Render the boxed Nushell-style table, fitting max_width columns.
+    /// When the natural layout is too wide, the first (name) column is
+    /// truncated with an ellipsis and the trailing columns are dropped if
+    /// that is still not enough — every row stays on a single line.
+    pub fn render(&self, color: bool, max_width: usize) -> String {
+        let max_width = max_width.max(20);
+        let headers = self.columns.clone();
+        if headers.is_empty() {
+            return String::new();
+        }
+        // Column 0 is the row index; the data columns follow.
+        let index_width = self.rows.len().to_string().len().max(1);
+        let mut natural: Vec<usize> = headers.iter().map(|h| visible_len(h)).collect();
+        let mut cells: Vec<Vec<String>> = Vec::new();
+        for (i, row) in self.rows.iter().enumerate() {
+            let mut line = vec![i.to_string()];
+            for cell in row {
+                line.push(cell.text.clone());
+            }
+            for (c, cell) in line.iter().enumerate().skip(1) {
+                natural[c - 1] = natural[c - 1].max(visible_len(cell));
+            }
+            cells.push(line);
+        }
+        let line_width = |ncols: usize, widths: &[usize]| -> usize {
+            1 + 3 * (ncols + 1) + index_width + widths.iter().sum::<usize>()
+        };
+
+        // Choose the final column set and widths.
+        let mut data_cols = headers.len();
+        let mut widths: Vec<usize> = natural.clone();
+        loop {
+            if data_cols == 0 {
+                break;
+            }
+            widths.truncate(data_cols);
+            if line_width(data_cols, &widths) <= max_width {
+                // Expand the first column into the remaining slack.
+                widths[0] += max_width - line_width(data_cols, &widths);
+                break;
+            }
+            // Cap the non-first columns, then give the first what remains.
+            let mut capped = widths.clone();
+            for w in capped.iter_mut().skip(1) {
+                *w = (*w).min(16);
+            }
+            if line_width(data_cols, &capped) <= max_width {
+                capped[0] += max_width - line_width(data_cols, &capped);
+                widths = capped;
+                break;
+            }
+            if data_cols == 1 {
+                // Last resort: shrink the single column to whatever remains
+                // after the borders and the index column.
+                let fixed = 1 + 3 * (data_cols + 1) + index_width;
+                capped[0] = max_width.saturating_sub(fixed).max(1);
+                widths = capped;
+                break;
+            }
+            data_cols -= 1;
+        }
+
+        let all_headers: Vec<String> = std::iter::once("#".to_string())
+            .chain(headers.iter().take(data_cols).cloned())
+            .collect();
+        let mut all_widths = vec![index_width];
+        all_widths.extend(widths.iter().cloned());
+
+        let border = |left: char, mid: char, right: char| -> String {
+            let mut line = String::new();
+            line.push(left);
+            for (i, w) in all_widths.iter().enumerate() {
+                if i > 0 {
+                    line.push(mid);
+                }
+                line.push_str(&"─".repeat(w + 2));
+            }
+            line.push(right);
+            line
+        };
+        let row_line = |row: &[String], bold: bool| -> String {
+            let mut line = String::from("│");
+            for (i, c) in row.iter().enumerate().take(all_widths.len()) {
+                line.push(' ');
+                let cell = fit_cell(c, all_widths[i]);
+                let rendered = if bold {
+                    cell.bold().to_string()
+                } else {
+                    cell
+                };
+                line.push_str(&rendered);
+                line.push(' ');
+                line.push('│');
+            }
+            line
+        };
+        let dim = |s: &str| -> String {
+            if color {
+                s.dimmed().to_string()
+            } else {
+                s.to_string()
+            }
+        };
+
+        let mut out = String::new();
+        out.push_str(&dim(&border('╭', '┬', '╮')));
+        out.push('\n');
+        out.push_str(&row_line(&all_headers, true));
+        out.push('\n');
+        out.push_str(&dim(&border('├', '┼', '┤')));
+        out.push('\n');
+        for line in &cells {
+            out.push_str(&row_line(line, false));
+            out.push('\n');
+        }
+        out.push_str(&dim(&border('╰', '┴', '╯')));
+        out.push('\n');
+        out
+    }
+}
+
+/// Parse a where value: "1mb"/"512kb"/"2gb" become byte sizes, numbers
+/// become numbers, everything else is a string.
+#[derive(Debug, Clone, PartialEq)]
+enum WhereValue {
+    Num(f64),
+    Bytes(u64),
+    Str(String),
+}
+
+fn parse_value(raw: &str) -> WhereValue {
+    let lower = raw.trim().to_lowercase();
+    for (suffix, mult) in [("gb", 1024u64.pow(3)), ("mb", 1024u64.pow(2)), ("kb", 1024)] {
+        if let Some(n) = lower.strip_suffix(suffix) {
+            if let Ok(v) = n.trim().parse::<f64>() {
+                return WhereValue::Bytes((v * mult as f64) as u64);
+            }
+        }
+    }
+    if let Ok(v) = raw.trim().parse::<f64>() {
+        return WhereValue::Num(v);
+    }
+    WhereValue::Str(raw.trim().to_string())
+}
+
+fn num_cmp(a: f64, b: f64, op: &str) -> bool {
+    match op {
+        ">" => a > b,
+        "<" => a < b,
+        ">=" => a >= b,
+        "<=" => a <= b,
+        "==" => (a - b).abs() < f64::EPSILON,
+        "!=" => (a - b).abs() >= f64::EPSILON,
+        _ => false,
+    }
+}
+
+/// Filter the rows of a table: where <field> <op> <value>.
+pub fn filter_where(table: &DataTable, field: &str, op: &str, value: &str) -> Result<DataTable> {
+    let Some(idx) = table.column_index(field) else {
+        bail!(
+            "unknown column '{field}' — available: {}",
+            table.columns.join(", ")
+        );
+    };
+    let val = parse_value(value);
+    let supported = matches!(op, ">" | "<" | ">=" | "<=" | "==" | "!=" | "=~");
+    if !supported {
+        bail!("unknown operator '{op}' — use > < >= <= == != =~");
+    }
+    let mut out = table.clone();
+    out.rows.retain(|row| match row.get(idx) {
+        None => false,
+        Some(cell) => match &val {
+            WhereValue::Num(n) => match cell.num {
+                Some(v) => num_cmp(v, *n, op),
+                None => false,
+            },
+            WhereValue::Bytes(b) => match cell.bytes {
+                Some(v) => num_cmp(v as f64, *b as f64, op),
+                None => false,
+            },
+            WhereValue::Str(s) => {
+                let text = strip_ansi(&cell.text);
+                match op {
+                    "==" => text.eq_ignore_ascii_case(s),
+                    "!=" => !text.eq_ignore_ascii_case(s),
+                    "=~" => text.to_lowercase().contains(&s.to_lowercase()),
+                    _ => false,
+                }
+            }
+        },
+    });
+    Ok(out)
+}
+
+/// Select one column: get <column>.
+pub fn get_column(table: &DataTable, field: &str) -> Result<DataTable> {
+    let Some(idx) = table.column_index(field) else {
+        bail!(
+            "unknown column '{field}' — available: {}",
+            table.columns.join(", ")
+        );
+    };
+    Ok(DataTable {
+        columns: vec![field.to_string()],
+        rows: table
+            .rows
+            .iter()
+            .map(|row| vec![row[idx].clone()])
+            .collect(),
+    })
+}
+
+/// Pad a cell to its column width, or truncate it (with an ellipsis,
+/// preserving any leading color codes) when it is too wide.
+fn fit_cell(s: &str, w: usize) -> String {
+    let n = visible_len(s);
+    if n <= w {
+        return format!("{s}{}", " ".repeat(w - n));
+    }
+    let plain = strip_ansi(s);
+    let mut cut: String = plain.chars().take(w.saturating_sub(1).max(1)).collect();
+    cut.push('…');
+    if s.contains('') {
+        let mut prefix = String::new();
+        let mut chars = s.chars().peekable();
+        while chars.peek() == Some(&'') {
+            for ch in chars.by_ref() {
+                prefix.push(ch);
+                if ch == 'm' {
+                    break;
+                }
+            }
+        }
+        format!("{prefix}{cut}")
+    } else {
+        cut
+    }
+}
+
+fn strip_ansi(s: &str) -> String {
+    let mut out = String::new();
+    let mut chars = s.chars();
+    while let Some(c) = chars.next() {
+        if c == '\u{1b}' {
+            for n in chars.by_ref() {
+                if n == 'm' {
+                    break;
+                }
+            }
+        } else {
+            out.push(c);
+        }
+    }
+    out
+}
+
+fn visible_len(s: &str) -> usize {
+    strip_ansi(s).chars().count()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn sample() -> DataTable {
+        DataTable {
+            columns: vec!["name".into(), "type".into(), "size".into()],
+            rows: vec![
+                vec![
+                    Cell::str("src"),
+                    Cell::str("dir"),
+                    Cell::bytes(2048, "2.0 KB".into()),
+                ],
+                vec![
+                    Cell::str("am.exe"),
+                    Cell::str("file"),
+                    Cell::bytes(5_000_000, "4.8 MB".into()),
+                ],
+                vec![
+                    Cell::str("readme.md"),
+                    Cell::str("file"),
+                    Cell::bytes(512, "512 B".into()),
+                ],
+            ],
+        }
+    }
+
+    #[test]
+    fn filters_numeric_and_size() {
+        let t = sample();
+        let big = filter_where(&t, "size", ">", "1mb").unwrap();
+        assert_eq!(big.rows.len(), 1);
+        assert_eq!(big.rows[0][0].text, "am.exe");
+        let eq = filter_where(&t, "type", "==", "dir").unwrap();
+        assert_eq!(eq.rows.len(), 1);
+        let contains = filter_where(&t, "name", "=~", "read").unwrap();
+        assert_eq!(contains.rows.len(), 1);
+    }
+
+    #[test]
+    fn get_selects_column() {
+        let t = sample();
+        let names = get_column(&t, "name").unwrap();
+        assert_eq!(names.columns, vec!["name".to_string()]);
+        assert_eq!(names.rows.len(), 3);
+        assert_eq!(names.rows[1][0].text, "am.exe");
+    }
+
+    #[test]
+    fn unknown_column_errors() {
+        let t = sample();
+        assert!(filter_where(&t, "nope", "==", "x").is_err());
+        assert!(get_column(&t, "nope").is_err());
+    }
+
+    #[test]
+    fn parses_where_values() {
+        assert_eq!(parse_value("1mb"), WhereValue::Bytes(1024 * 1024));
+        assert_eq!(parse_value("512kb"), WhereValue::Bytes(512 * 1024));
+        assert_eq!(parse_value("3.5"), WhereValue::Num(3.5));
+        assert_eq!(parse_value("hello"), WhereValue::Str("hello".into()));
+    }
+
+    #[test]
+    fn render_is_aligned() {
+        let t = sample();
+        let text = t.render(false, 200);
+        assert!(text.contains("╭"));
+        assert!(text.contains("name"));
+        assert!(text.contains("am.exe"));
+        let widths: Vec<usize> = text.lines().map(|l| l.chars().count()).collect();
+        assert!(widths.iter().all(|w| *w == widths[0]), "unaligned:\n{text}");
+    }
+
+    #[test]
+    fn render_fits_narrow_width() {
+        // A table whose first column is too long to fit naturally.
+        let t = DataTable {
+            columns: vec!["name".into(), "type".into(), "size".into()],
+            rows: vec![vec![
+                Cell::str("a-very-long-file-name-that-overflows.txt"),
+                Cell::str("file"),
+                Cell::bytes(512, "512 B".into()),
+            ]],
+        };
+        // Trailing columns are dropped when too narrow.
+        let text = t.render(false, 45);
+        for line in text.lines() {
+            assert!(line.chars().count() <= 45, "too wide: {line}");
+        }
+        assert!(!text.contains("size"));
+        // The name column is truncated with an ellipsis at the very end.
+        let text = t.render(false, 30);
+        for line in text.lines() {
+            assert!(line.chars().count() <= 30, "too wide: {line}");
+        }
+        assert!(text.contains("…"), "name should be truncated:
+{text}");
+    }
+
+    #[test]
+    fn fit_cell_truncates_and_keeps_color() {
+        let colored = "\u{1b}[34mverylongname\u{1b}[0m".to_string();
+        let out = fit_cell(&colored, 8);
+        assert_eq!(strip_ansi(&out).chars().count(), 8);
+        assert!(out.starts_with("\u{1b}["));
+    }
+}