Version 2.9.2

Works around Zig issue https://github.com/ziglang/zig/issues/25664

Fixes #266

ChangeLog

@@ -1,6 +1,31 @@
 # SPDX-FileCopyrightText: Yorhel <projects@yorhel.nl>
 # SPDX-License-Identifier: MIT
 
+2.9.2 - 2025-10-24
+	- Still requires Zig 0.14 or 0.15
+	- Fix hang on loading config file when compiled with Zig 0.15.2
+
+2.9.1 - 2025-08-21
+	- Add support for building with Zig 0.15
+	- Zig 0.14 is still supported
+
+2.9 - 2025-08-16
+	- Still requires Zig 0.14
+	- Add --delete-command option to replace the built-in file deletion
+	- Move term cursor to selected option in delete confirmation window
+	- Support binary import on older Linux kernels lacking statx() (may break
+	  again in the future, Zig does not officially support such old kernels)
+
+2.8.2 - 2025-05-01
+	- Still requires Zig 0.14
+	- Fix a build error on MacOS
+
+2.8.1 - 2025-04-28
+	- Still requires Zig 0.14
+	- Fix integer overflow in binary export
+	- Fix crash when `fstatat()` returns EINVAL
+	- Minor build system improvements
+
 2.8 - 2025-03-05
 	- Now requires Zig 0.14
 	- Add support for @-prefixed lines to ignore errors in config file

README.md

@@ -19,7 +19,7 @@ C version (1.x).
 
 ## Requirements
 
-- Zig 0.14
+- Zig 0.14 or 0.15
 - Some sort of POSIX-like OS
 - ncurses
 - libzstd

build.zig

@@ -7,21 +7,24 @@ pub fn build(b: *std.Build) void {
     const target = b.standardTargetOptions(.{});
     const optimize = b.standardOptimizeOption(.{});
 
-    const pie = b.option(bool, "pie", "Build with PIE support (by default false)") orelse false;
+    const pie = b.option(bool, "pie", "Build with PIE support (by default: target-dependant)");
     const strip = b.option(bool, "strip", "Strip debugging info (by default false)") orelse false;
 
-    const exe = b.addExecutable(.{
-        .name = "ncdu",
+    const main_mod = b.createModule(.{
         .root_source_file = b.path("src/main.zig"),
         .target = target,
         .optimize = optimize,
         .strip = strip,
         .link_libc = true,
     });
+    main_mod.linkSystemLibrary("ncursesw", .{});
+    main_mod.linkSystemLibrary("zstd", .{});
 
+    const exe = b.addExecutable(.{
+        .name = "ncdu",
+        .root_module = main_mod,
+    });
     exe.pie = pie;
-    exe.root_module.linkSystemLibrary("ncursesw", .{});
-    exe.root_module.linkSystemLibrary("libzstd", .{});
     // https://github.com/ziglang/zig/blob/faccd79ca5debbe22fe168193b8de54393257604/build.zig#L745-L748
     if (target.result.os.tag.isDarwin()) {
         // useful for package maintainers
@@ -39,14 +42,9 @@ pub fn build(b: *std.Build) void {
     run_step.dependOn(&run_cmd.step);
 
     const unit_tests = b.addTest(.{
-        .root_source_file = b.path("src/main.zig"),
-        .target = target,
-        .optimize = optimize,
-        .link_libc = true,
+        .root_module = main_mod,
     });
     unit_tests.pie = pie;
-    unit_tests.root_module.linkSystemLibrary("ncursesw", .{});
-    unit_tests.root_module.linkSystemLibrary("libzstd", .{});
 
     const run_unit_tests = b.addRunArtifact(unit_tests);
 

ncdu.1

@@ -1,6 +1,6 @@
 .\" SPDX-FileCopyrightText: Yorhel <projects@yorhel.nl>
 .\" SPDX-License-Identifier: MIT
-.Dd March 5, 2025
+.Dd August 16, 2025
 .Dt NCDU 1
 .Os
 .Sh NAME
@@ -44,6 +44,7 @@
 .Op Fl \-group\-directories\-first , \-no\-group\-directories\-first
 .Op Fl \-confirm\-quit , \-no\-confirm\-quit
 .Op Fl \-confirm\-delete , \-no\-confirm\-delete
+.Op Fl \-delete\-command Ar command
 .Op Fl \-color Ar off | dark | dark-bg
 .Op Ar path
 .Nm
@@ -359,6 +360,31 @@ Can be helpful when you accidentally press 'q' during or after a very long scan.
 Require a confirmation before deleting a file or directory.
 Enabled by default, but can be disabled if you're absolutely sure you won't
 accidentally press 'd'.
+.It Fl \-delete\-command Ar command
+When set to a non-empty string, replace the built-in file deletion feature with
+a custom shell command.
+.Pp
+The absolute path of the item to be deleted is appended to the given command
+and the result is evaluated in a shell.
+The command is run from the same directory that ncdu itself was started in.
+The
+.Ev NCDU_DELETE_PATH
+environment variable is set to the absolute path of the item to be deleted and
+.Ev NCDU_LEVEL
+is set in the same fashion as when spawning a shell from within ncdu.
+.Pp
+After command completion, the in-memory view of the selected item is refreshed
+and directory sizes are adjusted as necessary.
+This is not a full refresh of the complete directory tree, so if the item has
+been renamed or moved to another directory, it's new location is not
+automatically picked up.
+.Pp
+For example, to use
+.Xr rm 1
+interactive mode to prompt before each deletion:
+.Dl ncdu --no-confirm-delete --delete-command \[aq]rm -ri --\[aq]
+Or to move files to trash:
+.Dl ncdu --delete-command \[aq]gio trash --\[aq]
 .It Fl \-color Ar off | dark | dark-bg
 Set the color scheme.
 The following schemes are recognized:

src/bin_export.zig

@@ -11,14 +11,12 @@ const c = @import("c.zig").c;
 
 pub const global = struct {
     var fd: std.fs.File = undefined;
-    var index = std.ArrayList(u8).init(main.allocator);
+    var index: std.ArrayListUnmanaged(u8) = .empty;
     var file_off: u64 = 0;
     var lock: std.Thread.Mutex = .{};
     var root_itemref: u64 = 0;
 };
 
-const BLOCK_SIZE: usize = 64*1024;
-
 pub const SIGNATURE = "\xbfncduEX1";
 
 pub const ItemKey = enum(u5) {
@@ -81,10 +79,15 @@ fn blockSize(num: u32) usize {
       else                     2048<<10; // 32768
 }
 
+// Upper bound on the return value of blockSize()
+// (config.export_block_size may be larger than the sizes listed above, let's
+// stick with the maximum block size supported by the file format to be safe)
+const MAX_BLOCK_SIZE: usize = 1<<28;
+
 
 pub const Thread = struct {
     buf: []u8 = undefined,
-    off: usize = std.math.maxInt(usize) - (1<<10), // large number to trigger a flush() for the first write
+    off: usize = MAX_BLOCK_SIZE, // pretend we have a full block to trigger a flush() for the first write
     block_num: u32 = std.math.maxInt(u32),
     itemref: u64 = 0, // ref of item currently being written
 
@@ -102,11 +105,11 @@ pub const Thread = struct {
         }
     }
 
-    fn createBlock(t: *Thread) std.ArrayList(u8) {
-        var out = std.ArrayList(u8).init(main.allocator);
+    fn createBlock(t: *Thread) std.ArrayListUnmanaged(u8) {
+        var out: std.ArrayListUnmanaged(u8) = .empty;
         if (t.block_num == std.math.maxInt(u32) or t.off == 0) return out;
 
-        out.ensureTotalCapacityPrecise(12 + @as(usize, @intCast(c.ZSTD_COMPRESSBOUND(@as(c_int, @intCast(t.off)))))) catch unreachable;
+        out.ensureTotalCapacityPrecise(main.allocator, 12 + @as(usize, @intCast(c.ZSTD_COMPRESSBOUND(@as(c_int, @intCast(t.off)))))) catch unreachable;
         out.items.len = out.capacity;
         const bodylen = compressZstd(t.buf[0..t.off], out.items[8..]);
         out.items.len = 12 + bodylen;
@@ -119,12 +122,12 @@ pub const Thread = struct {
 
     fn flush(t: *Thread, expected_len: usize) void {
         @branchHint(.unlikely);
-        const block = createBlock(t);
-        defer block.deinit();
+        var block = createBlock(t);
+        defer block.deinit(main.allocator);
 
         global.lock.lock();
         defer global.lock.unlock();
-        // This can only really happen when the root path exceeds BLOCK_SIZE,
+        // This can only really happen when the root path exceeds our block size,
         // in which case we would probably have error'ed out earlier anyway.
         if (expected_len > t.buf.len) ui.die("Error writing data: path too long.\n", .{});
 
@@ -138,7 +141,7 @@ pub const Thread = struct {
 
         t.off = 0;
         t.block_num = @intCast((global.index.items.len - 4) / 8);
-        global.index.appendSlice(&[1]u8{0}**8) catch unreachable;
+        global.index.appendSlice(main.allocator, &[1]u8{0}**8) catch unreachable;
         if (global.index.items.len + 12 >= (1<<28)) ui.die("Too many data blocks, please report a bug.\n", .{});
 
         const newsize = blockSize(t.block_num);
@@ -430,7 +433,7 @@ pub const Dir = struct {
 
 pub fn createRoot(stat: *const sink.Stat, threads: []sink.Thread) Dir {
     for (threads) |*t| {
-        t.sink.bin.buf = main.allocator.alloc(u8, BLOCK_SIZE) catch unreachable;
+        t.sink.bin.buf = main.allocator.alloc(u8, blockSize(0)) catch unreachable;
     }
 
     return .{ .stat = stat.* };
@@ -444,12 +447,12 @@ pub fn done(threads: []sink.Thread) void {
 
     while (std.mem.endsWith(u8, global.index.items, &[1]u8{0}**8))
         global.index.shrinkRetainingCapacity(global.index.items.len - 8);
-    global.index.appendSlice(&bigu64(global.root_itemref)) catch unreachable;
-    global.index.appendSlice(&blockHeader(1, @intCast(global.index.items.len + 4))) catch unreachable;
+    global.index.appendSlice(main.allocator, &bigu64(global.root_itemref)) catch unreachable;
+    global.index.appendSlice(main.allocator, &blockHeader(1, @intCast(global.index.items.len + 4))) catch unreachable;
     global.index.items[0..4].* = blockHeader(1, @intCast(global.index.items.len));
     global.fd.writeAll(global.index.items) catch |e|
         ui.die("Error writing to file: {s}.\n", .{ ui.errorString(e) });
-    global.index.clearAndFree();
+    global.index.clearAndFree(main.allocator);
 
     global.fd.close();
 }
@@ -461,5 +464,5 @@ pub fn setupOutput(fd: std.fs.File) void {
     global.file_off = 8;
 
     // Placeholder for the index block header.
-    global.index.appendSlice("aaaa") catch unreachable;
+    global.index.appendSlice(main.allocator, "aaaa") catch unreachable;
 }

src/bin_reader.zig

@@ -504,7 +504,9 @@ pub fn import() void {
 pub fn open(fd: std.fs.File) !void {
     global.fd = fd;
 
-    const size = try fd.getEndPos();
+    // Do not use fd.getEndPos() because that requires newer kernels supporting statx() #261.
+    try fd.seekFromEnd(0);
+    const size = try fd.getPos();
     if (size < 16) return error.EndOfStream;
 
     // Read index block

src/browser.zig

@@ -15,16 +15,16 @@ const util = @import("util.zig");
 // Currently opened directory.
 pub var dir_parent: *model.Dir = undefined;
 pub var dir_path: [:0]u8 = undefined;
-var dir_parents = std.ArrayList(model.Ref).init(main.allocator);
+var dir_parents: std.ArrayListUnmanaged(model.Ref) = .empty;
 var dir_alloc = std.heap.ArenaAllocator.init(main.allocator);
 
 // Used to keep track of which dir is which ref, so we can enter it.
 // Only used for binreader browsing.
-var dir_refs = std.ArrayList(struct { ptr: *model.Dir, ref: u64 }).init(main.allocator);
+var dir_refs: std.ArrayListUnmanaged(struct { ptr: *model.Dir, ref: u64 }) = .empty;
 
 // Sorted list of all items in the currently opened directory.
 // (first item may be null to indicate the "parent directory" item)
-var dir_items = std.ArrayList(?*model.Entry).init(main.allocator);
+var dir_items: std.ArrayListUnmanaged(?*model.Entry) = .empty;
 
 var dir_max_blocks: u64 = 0;
 var dir_max_size: u64 = 0;
@@ -146,7 +146,7 @@ pub fn loadDir(next_sel: u64) void {
     dir_has_shared = false;
 
     if (dir_parents.items.len > 1)
-        dir_items.append(null) catch unreachable;
+        dir_items.append(main.allocator, null) catch unreachable;
     var ref = dir_parent.sub;
     while (!ref.isNull()) {
         const e =
@@ -164,10 +164,10 @@ pub fn loadDir(next_sel: u64) void {
             break :blk !excl and name[0] != '.' and name[name.len-1] != '~';
         };
         if (shown) {
-            dir_items.append(e) catch unreachable;
+            dir_items.append(main.allocator, e) catch unreachable;
             if (e.dir()) |d| {
                 if (d.shared_blocks > 0 or d.shared_size > 0) dir_has_shared = true;
-                if (main.config.binreader) dir_refs.append(.{ .ptr = d, .ref = ref.ref }) catch unreachable;
+                if (main.config.binreader) dir_refs.append(main.allocator, .{ .ptr = d, .ref = ref.ref }) catch unreachable;
             }
         }
 
@@ -185,10 +185,10 @@ pub fn initRoot() void {
     if (main.config.binreader) {
         const ref = bin_reader.getRoot();
         dir_parent = bin_reader.get(ref, main.allocator).dir() orelse ui.die("Invalid import\n", .{});
-        dir_parents.append(.{ .ref = ref }) catch unreachable;
+        dir_parents.append(main.allocator, .{ .ref = ref }) catch unreachable;
     } else {
         dir_parent = model.root;
-        dir_parents.append(.{ .ptr = &dir_parent.entry }) catch unreachable;
+        dir_parents.append(main.allocator, .{ .ptr = &dir_parent.entry }) catch unreachable;
     }
     dir_path = main.allocator.dupeZ(u8, dir_parent.entry.name()) catch unreachable;
     loadDir(0);
@@ -202,10 +202,10 @@ fn enterSub(e: *model.Dir) void {
         };
         dir_parent.entry.destroy(main.allocator);
         dir_parent = bin_reader.get(ref, main.allocator).dir() orelse unreachable;
-        dir_parents.append(.{ .ref = ref }) catch unreachable;
+        dir_parents.append(main.allocator, .{ .ref = ref }) catch unreachable;
     } else {
         dir_parent = e;
-        dir_parents.append(.{ .ptr = &e.entry }) catch unreachable;
+        dir_parents.append(main.allocator, .{ .ptr = &e.entry }) catch unreachable;
     }
 
     const newpath = std.fs.path.joinZ(main.allocator, &[_][]const u8{ dir_path, e.entry.name() }) catch unreachable;
@@ -430,7 +430,7 @@ const info = struct {
 
     var tab: Tab = .info;
     var entry: ?*model.Entry = null;
-    var links: ?std.ArrayList(*model.Link) = null;
+    var links: ?std.ArrayListUnmanaged(*model.Link) = null;
     var links_top: usize = 0;
     var links_idx: usize = 0;
 
@@ -445,7 +445,7 @@ const info = struct {
     // Set the displayed entry to the currently selected item and open the tab.
     fn set(e: ?*model.Entry, t: Tab) void {
         if (e != entry) {
-            if (links) |*l| l.deinit();
+            if (links) |*l| l.deinit(main.allocator);
             links = null;
             links_top = 0;
             links_idx = 0;
@@ -458,10 +458,10 @@ const info = struct {
         state = .info;
         tab = t;
         if (tab == .links and links == null and !main.config.binreader) {
-            var list = std.ArrayList(*model.Link).init(main.allocator);
+            var list: std.ArrayListUnmanaged(*model.Link) = .empty;
             var l = e.?.link().?;
             while (true) {
-                list.append(l) catch unreachable;
+                list.append(main.allocator, l) catch unreachable;
                 l = l.next;
                 if (&l.entry == e)
                     break;

src/delete.zig

@@ -6,6 +6,9 @@ const main = @import("main.zig");
 const model = @import("model.zig");
 const ui = @import("ui.zig");
 const browser = @import("browser.zig");
+const scan = @import("scan.zig");
+const sink = @import("sink.zig");
+const mem_sink = @import("mem_sink.zig");
 const util = @import("util.zig");
 const c = @import("c.zig").c;
 
@@ -68,6 +71,57 @@ fn deleteItem(dir: std.fs.Dir, path: [:0]const u8, ptr: *align(1) ?*model.Entry)
     return false;
 }
 
+// Returns true if the item has been deleted successfully.
+fn deleteCmd(path: [:0]const u8, ptr: *align(1) ?*model.Entry) bool {
+    {
+        var env = std.process.getEnvMap(main.allocator) catch unreachable;
+        defer env.deinit();
+        env.put("NCDU_DELETE_PATH", path) catch unreachable;
+
+        // Since we're passing the path as an environment variable and go through
+        // the shell anyway, we can refer to the variable and avoid error-prone
+        // shell escaping.
+        const cmd = std.fmt.allocPrint(main.allocator, "{s} \"$NCDU_DELETE_PATH\"", .{main.config.delete_command}) catch unreachable;
+        defer main.allocator.free(cmd);
+        ui.runCmd(&.{"/bin/sh", "-c", cmd}, null, &env, true);
+    }
+
+    const stat = scan.statAt(std.fs.cwd(), path, false, null) catch {
+        // Stat failed. Would be nice to display an error if it's not
+        // 'FileNotFound', but w/e, let's just assume the item has been
+        // deleted as expected.
+        ptr.*.?.zeroStats(parent);
+        ptr.* = ptr.*.?.next.ptr;
+        return true;
+    };
+
+    // If either old or new entry is not a dir, remove & re-add entry in the in-memory tree.
+    if (ptr.*.?.pack.etype != .dir or stat.etype != .dir) {
+        ptr.*.?.zeroStats(parent);
+        const e = model.Entry.create(main.allocator, stat.etype, main.config.extended and !stat.ext.isEmpty(), ptr.*.?.name());
+        e.next.ptr = ptr.*.?.next.ptr;
+        mem_sink.statToEntry(&stat, e, parent);
+        ptr.* = e;
+
+        var it : ?*model.Dir = parent;
+        while (it) |p| : (it = p.parent) {
+            if (stat.etype != .link) {
+                p.entry.pack.blocks +|= e.pack.blocks;
+                p.entry.size +|= e.size;
+            }
+            p.items +|= 1;
+        }
+    }
+
+    // If new entry is a dir, recursively scan.
+    if (ptr.*.?.dir()) |d| {
+        main.state = .refresh;
+        sink.global.sink = .mem;
+        mem_sink.global.root = d;
+    }
+    return false;
+}
+
 // Returns the item that should be selected in the browser.
 pub fn delete() ?*model.Entry {
     while (main.state == .delete and state == .confirm)
@@ -82,30 +136,46 @@ pub fn delete() ?*model.Entry {
         if (it.* == entry)
             break;
 
-    var path = std.ArrayList(u8).init(main.allocator);
-    defer path.deinit();
-    parent.fmtPath(true, &path);
+    var path: std.ArrayListUnmanaged(u8) = .empty;
+    defer path.deinit(main.allocator);
+    parent.fmtPath(main.allocator, true, &path);
     if (path.items.len == 0 or path.items[path.items.len-1] != '/')
-        path.append('/') catch unreachable;
-    path.appendSlice(entry.name()) catch unreachable;
+        path.append(main.allocator, '/') catch unreachable;
+    path.appendSlice(main.allocator, entry.name()) catch unreachable;
 
-    _ = deleteItem(std.fs.cwd(), util.arrayListBufZ(&path), it);
-    model.inodes.addAllStats();
-    return if (it.* == e) e else next_sel;
+    if (main.config.delete_command.len == 0) {
+        _ = deleteItem(std.fs.cwd(), util.arrayListBufZ(&path, main.allocator), it);
+        model.inodes.addAllStats();
+        return if (it.* == e) e else next_sel;
+    } else {
+        const isdel = deleteCmd(util.arrayListBufZ(&path, main.allocator), it);
+        model.inodes.addAllStats();
+        return if (isdel) next_sel else it.*;
+    }
 }
 
 fn drawConfirm() void {
     browser.draw();
     const box = ui.Box.create(6, 60, "Confirm delete");
     box.move(1, 2);
-    ui.addstr("Are you sure you want to delete \"");
-    ui.addstr(ui.shorten(ui.toUtf8(entry.name()), 21));
-    ui.addch('"');
-    if (entry.pack.etype != .dir)
-        ui.addch('?')
-    else {
-        box.move(2, 18);
-        ui.addstr("and all of its contents?");
+    if (main.config.delete_command.len == 0) {
+        ui.addstr("Are you sure you want to delete \"");
+        ui.addstr(ui.shorten(ui.toUtf8(entry.name()), 21));
+        ui.addch('"');
+        if (entry.pack.etype != .dir)
+            ui.addch('?')
+        else {
+            box.move(2, 18);
+            ui.addstr("and all of its contents?");
+        }
+    } else {
+        ui.addstr("Are you sure you want to run \"");
+        ui.addstr(ui.shorten(ui.toUtf8(main.config.delete_command), 25));
+        ui.addch('"');
+        box.move(2, 4);
+        ui.addstr("on \"");
+        ui.addstr(ui.shorten(ui.toUtf8(entry.name()), 50));
+        ui.addch('"');
     }
 
     box.move(4, 15);
@@ -119,20 +189,25 @@ fn drawConfirm() void {
     box.move(4, 31);
     ui.style(if (confirm == .ignore) .sel else .default);
     ui.addstr("don't ask me again");
+    box.move(4, switch (confirm) {
+        .yes    => 15,
+        .no     => 25,
+        .ignore => 31
+    });
 }
 
 fn drawProgress() void {
-    var path = std.ArrayList(u8).init(main.allocator);
-    defer path.deinit();
-    parent.fmtPath(false, &path);
-    path.append('/') catch unreachable;
-    path.appendSlice(entry.name()) catch unreachable;
+    var path: std.ArrayListUnmanaged(u8) = .empty;
+    defer path.deinit(main.allocator);
+    parent.fmtPath(main.allocator, false, &path);
+    path.append(main.allocator, '/') catch unreachable;
+    path.appendSlice(main.allocator, entry.name()) catch unreachable;
 
     // TODO: Item counts and progress bar would be nice.
 
     const box = ui.Box.create(6, 60, "Deleting...");
     box.move(2, 2);
-    ui.addstr(ui.shorten(ui.toUtf8(util.arrayListBufZ(&path)), 56));
+    ui.addstr(ui.shorten(ui.toUtf8(util.arrayListBufZ(&path, main.allocator)), 56));
     box.move(4, 41);
     ui.addstr("Press ");
     ui.style(.key);
@@ -142,16 +217,16 @@ fn drawProgress() void {
 }
 
 fn drawErr() void {
-    var path = std.ArrayList(u8).init(main.allocator);
-    defer path.deinit();
-    parent.fmtPath(false, &path);
-    path.append('/') catch unreachable;
-    path.appendSlice(entry.name()) catch unreachable;
+    var path: std.ArrayListUnmanaged(u8) = .empty;
+    defer path.deinit(main.allocator);
+    parent.fmtPath(main.allocator, false, &path);
+    path.append(main.allocator, '/') catch unreachable;
+    path.appendSlice(main.allocator, entry.name()) catch unreachable;
 
     const box = ui.Box.create(6, 60, "Error");
     box.move(1, 2);
     ui.addstr("Error deleting ");
-    ui.addstr(ui.shorten(ui.toUtf8(util.arrayListBufZ(&path)), 41));
+    ui.addstr(ui.shorten(ui.toUtf8(util.arrayListBufZ(&path, main.allocator)), 41));
     box.move(2, 4);
     ui.addstr(ui.errorString(error_code));
 

src/exclude.zig

@@ -123,7 +123,7 @@ test "parse" {
 fn PatternList(comptime withsub: bool) type {
     return struct {
         literals: std.HashMapUnmanaged(*const Pattern, Val, Ctx, 80) = .{},
-        wild: std.ArrayListUnmanaged(*const Pattern) = .{},
+        wild: std.ArrayListUnmanaged(*const Pattern) = .empty,
 
         // Not a fan of the map-of-arrays approach in the 'withsub' case, it
         // has a lot of extra allocations. Linking the Patterns together in a

src/main.zig

@@ -1,7 +1,7 @@
 // SPDX-FileCopyrightText: Yorhel <projects@yorhel.nl>
 // SPDX-License-Identifier: MIT
 
-pub const program_version = "2.8";
+pub const program_version = "2.9.2";
 
 const std = @import("std");
 const model = @import("model.zig");
@@ -80,7 +80,6 @@ pub const config = struct {
     pub var follow_symlinks: bool = false;
     pub var exclude_caches: bool = false;
     pub var exclude_kernfs: bool = false;
-    pub var exclude_patterns: std.ArrayList([:0]const u8) = std.ArrayList([:0]const u8).init(allocator);
     pub var threads: usize = 1;
     pub var complevel: u8 = 4;
     pub var compress: bool = false;
@@ -114,10 +113,14 @@ pub const config = struct {
     pub var confirm_quit: bool = false;
     pub var confirm_delete: bool = true;
     pub var ignore_delete_errors: bool = false;
+    pub var delete_command: [:0]const u8 = "";
 };
 
 pub var state: enum { scan, browse, refresh, shell, delete } = .scan;
 
+const stdin = if (@hasDecl(std.io, "getStdIn")) std.io.getStdIn() else std.fs.File.stdin();
+const stdout = if (@hasDecl(std.io, "getStdOut")) std.io.getStdOut() else std.fs.File.stdout();
+
 // Simple generic argument parser, supports getopt_long() style arguments.
 const Args = struct {
     lst: []const [:0]const u8,
@@ -306,6 +309,7 @@ fn argConfig(args: *Args, opt: Args.Option, infile: bool) !void {
     else if (opt.is("--no-confirm-quit")) config.confirm_quit = false
     else if (opt.is("--confirm-delete")) config.confirm_delete = true
     else if (opt.is("--no-confirm-delete")) config.confirm_delete = false
+    else if (opt.is("--delete-command")) config.delete_command = allocator.dupeZ(u8, try args.arg()) catch unreachable
     else if (opt.is("--color")) {
         const val = try args.arg();
         if (std.mem.eql(u8, val, "off")) config.ui_color = .off
@@ -326,19 +330,13 @@ fn tryReadArgsFile(path: [:0]const u8) void {
     };
     defer f.close();
 
-    var rd_ = std.io.bufferedReader(f.reader());
-    const rd = rd_.reader();
-
     var line_buf: [4096]u8 = undefined;
-    var line_fbs = std.io.fixedBufferStream(&line_buf);
-    const line_writer = line_fbs.writer();
+    var line_rd = util.LineReader.init(f, &line_buf);
 
-    while (true) : (line_fbs.reset()) {
-        rd.streamUntilDelimiter(line_writer, '\n', line_buf.len) catch |err| switch (err) {
-            error.EndOfStream => if (line_fbs.getPos() catch unreachable == 0) break,
-            else => |e| ui.die("Error reading from {s}: {s}\nRun with --ignore-config to skip reading config files.\n", .{ path, ui.errorString(e) }),
-        };
-        const line_ = line_fbs.getWritten();
+    while (true) {
+        const line_ = (line_rd.read() catch |e|
+            ui.die("Error reading from {s}: {s}\nRun with --ignore-config to skip reading config files.\n", .{ path, ui.errorString(e) })
+        ) orelse break;
 
         var argc: usize = 0;
         var ignerror = false;
@@ -373,13 +371,11 @@ fn tryReadArgsFile(path: [:0]const u8) void {
 }
 
 fn version() noreturn {
-    const stdout = std.io.getStdOut();
     stdout.writeAll("ncdu " ++ program_version ++ "\n") catch {};
     std.process.exit(0);
 }
 
 fn help() noreturn {
-    const stdout = std.io.getStdOut();
     stdout.writeAll(
     \\ncdu <options> <directory>
     \\
@@ -428,6 +424,7 @@ fn help() noreturn {
     \\  --group-directories-first  Sort directories before files
     \\  --confirm-quit             Ask confirmation before quitting ncdu
     \\  --no-confirm-delete        Don't ask confirmation before deletion
+    \\  --delete-command CMD       Command to run for file deletion
     \\  --color SCHEME             off / dark / dark-bg
     \\
     \\Refer to `man ncdu` for more information.
@@ -437,75 +434,13 @@ fn help() noreturn {
 }
 
 
-fn spawnShell() void {
-    ui.deinit();
-    defer ui.init();
-
-    var env = std.process.getEnvMap(allocator) catch unreachable;
-    defer env.deinit();
-    // NCDU_LEVEL can only count to 9, keeps the implementation simple.
-    if (env.get("NCDU_LEVEL")) |l|
-        env.put("NCDU_LEVEL", if (l.len == 0) "1" else switch (l[0]) {
-            '0'...'8' => |d| &[1] u8{d+1},
-            '9' => "9",
-            else => "1"
-        }) catch unreachable
-    else
-        env.put("NCDU_LEVEL", "1") catch unreachable;
-
-    const shell = std.posix.getenvZ("NCDU_SHELL") orelse std.posix.getenvZ("SHELL") orelse "/bin/sh";
-    var child = std.process.Child.init(&.{shell}, allocator);
-    child.cwd = browser.dir_path;
-    child.env_map = &env;
-
-    const stdin = std.io.getStdIn();
-    const stderr = std.io.getStdErr();
-    const term = child.spawnAndWait() catch |e| blk: {
-        stderr.writer().print(
-            "Error spawning shell: {s}\n\nPress enter to continue.\n",
-            .{ ui.errorString(e) }
-        ) catch {};
-        stdin.reader().skipUntilDelimiterOrEof('\n') catch unreachable;
-        break :blk std.process.Child.Term{ .Exited = 0 };
-    };
-    if (term != .Exited) {
-        const n = switch (term) {
-            .Exited  => "status",
-            .Signal  => "signal",
-            .Stopped => "stopped",
-            .Unknown => "unknown",
-        };
-        const v = switch (term) {
-            .Exited  => |v| v,
-            .Signal  => |v| v,
-            .Stopped => |v| v,
-            .Unknown => |v| v,
-        };
-        stderr.writer().print(
-            "Shell returned with {s} code {}.\n\nPress enter to continue.\n", .{ n, v }
-        ) catch {};
-        stdin.reader().skipUntilDelimiterOrEof('\n') catch unreachable;
-    }
-}
-
-
 fn readExcludeFile(path: [:0]const u8) !void {
     const f = try std.fs.cwd().openFileZ(path, .{});
     defer f.close();
 
-    var rd_ = std.io.bufferedReader(f.reader());
-    const rd = rd_.reader();
-
     var line_buf: [4096]u8 = undefined;
-    var line_fbs = std.io.fixedBufferStream(&line_buf);
-    const line_writer = line_fbs.writer();
-
-    while (true) : (line_fbs.reset()) {
-        rd.streamUntilDelimiter(line_writer, '\n', line_buf.len) catch |err| switch (err) {
-            error.EndOfStream => if (line_fbs.getPos() catch unreachable == 0) break,
-            else => |e| return e,
-        };
-        const line = line_fbs.getWritten();
+    var line_rd = util.LineReader.init(f, &line_buf);
+    while (try line_rd.read()) |line| {
         if (line.len > 0)
             exclude.addPattern(line);
     }
@@ -513,12 +448,12 @@ fn readExcludeFile(path: [:0]const u8) !void {
 
 fn readImport(path: [:0]const u8) !void {
     const fd =
-        if (std.mem.eql(u8, "-", path)) std.io.getStdIn()
+        if (std.mem.eql(u8, "-", path)) stdin
         else try std.fs.cwd().openFileZ(path, .{});
     errdefer fd.close();
 
     var buf: [8]u8 = undefined;
-    try fd.reader().readNoEof(&buf);
+    if (8 != try fd.readAll(&buf)) return error.EndOfStream;
     if (std.mem.eql(u8, &buf, bin_export.SIGNATURE)) {
         try bin_reader.open(fd);
         config.binreader = true;
@@ -600,8 +535,6 @@ pub fn main() void {
     if (@import("builtin").os.tag != .linux and config.exclude_kernfs)
         ui.die("The --exclude-kernfs flag is currently only supported on Linux.\n", .{});
 
-    const stdin = std.io.getStdIn();
-    const stdout = std.io.getStdOut();
     const out_tty = stdout.isTty();
     const in_tty = stdin.isTty();
     if (config.scan_ui == null) {
@@ -659,10 +592,10 @@ pub fn main() void {
     while (true) {
         switch (state) {
             .refresh => {
-                var full_path = std.ArrayList(u8).init(allocator);
-                defer full_path.deinit();
-                mem_sink.global.root.?.fmtPath(true, &full_path);
-                scan.scan(util.arrayListBufZ(&full_path)) catch {
+                var full_path: std.ArrayListUnmanaged(u8) = .empty;
+                defer full_path.deinit(allocator);
+                mem_sink.global.root.?.fmtPath(allocator, true, &full_path);
+                scan.scan(util.arrayListBufZ(&full_path, allocator)) catch {
                     sink.global.last_error = allocator.dupeZ(u8, full_path.items) catch unreachable;
                     sink.global.state = .err;
                     while (state == .refresh) handleEvent(true, true);
@@ -671,13 +604,18 @@ pub fn main() void {
                 browser.loadDir(0);
             },
             .shell => {
-                spawnShell();
+                const shell = std.posix.getenvZ("NCDU_SHELL") orelse std.posix.getenvZ("SHELL") orelse "/bin/sh";
+                var env = std.process.getEnvMap(allocator) catch unreachable;
+                defer env.deinit();
+                ui.runCmd(&.{shell}, browser.dir_path, &env, false);
                 state = .browse;
             },
             .delete => {
                 const next = delete.delete();
-                state = .browse;
-                browser.loadDir(if (next) |n| n.nameHash() else 0);
+                if (state != .refresh) {
+                    state = .browse;
+                    browser.loadDir(if (next) |n| n.nameHash() else 0);
+                }
             },
             else => handleEvent(true, false)
         }

src/mem_sink.zig

@@ -17,6 +17,24 @@ pub const Thread = struct {
     arena: std.heap.ArenaAllocator = std.heap.ArenaAllocator.init(std.heap.page_allocator),
 };
 
+pub fn statToEntry(stat: *const sink.Stat, e: *model.Entry, parent: *model.Dir) void {
+    e.pack.blocks = stat.blocks;
+    e.size = stat.size;
+    if (e.dir()) |d| {
+        d.parent = parent;
+        d.pack.dev = model.devices.getId(stat.dev);
+    }
+    if (e.link()) |l| {
+        l.parent = parent;
+        l.ino = stat.ino;
+        l.pack.nlink = stat.nlink;
+        model.inodes.lock.lock();
+        defer model.inodes.lock.unlock();
+        l.addLink();
+    }
+    if (e.ext()) |ext| ext.* = stat.ext;
+}
+
 pub const Dir = struct {
     dir: *model.Dir,
     entries: Map,
@@ -107,21 +125,7 @@ pub const Dir = struct {
         }
 
         const e = self.getEntry(t, stat.etype, main.config.extended and !stat.ext.isEmpty(), name);
-        e.pack.blocks = stat.blocks;
-        e.size = stat.size;
-        if (e.dir()) |d| {
-            d.parent = self.dir;
-            d.pack.dev = model.devices.getId(stat.dev);
-        }
-        if (e.link()) |l| {
-            l.parent = self.dir;
-            l.ino = stat.ino;
-            l.pack.nlink = stat.nlink;
-            model.inodes.lock.lock();
-            defer model.inodes.lock.unlock();
-            l.addLink();
-        }
-        if (e.ext()) |ext| ext.* = stat.ext;
+        statToEntry(stat, e, self.dir);
         return e;
     }
 

src/mem_src.zig

@@ -60,10 +60,10 @@ pub fn run(d: *model.Dir) void {
         .sink = &sink_threads[0],
         .stat = toStat(&d.entry),
     };
-    var buf = std.ArrayList(u8).init(main.allocator);
-    d.fmtPath(true, &buf);
+    var buf: std.ArrayListUnmanaged(u8) = .empty;
+    d.fmtPath(main.allocator, true, &buf);
     const root = sink.createRoot(buf.items, &ctx.stat);
-    buf.deinit();
+    buf.deinit(main.allocator);
 
     var it = d.sub.ptr;
     while (it) |e| : (it = e.next.ptr) rec(&ctx, root, e);

src/model.zig

@@ -109,7 +109,8 @@ pub const Entry = extern struct {
     fn alloc(comptime T: type, allocator: std.mem.Allocator, etype: EType, isext: bool, ename: []const u8) *Entry {
         const size = (if (isext) @as(usize, @sizeOf(Ext)) else 0) + @sizeOf(T) + ename.len + 1;
         var ptr = blk: while (true) {
-            if (allocator.allocWithOptions(u8, size, 1, null)) |p| break :blk p
+            const alignment = if (@typeInfo(@TypeOf(std.mem.Allocator.allocWithOptions)).@"fn".params[3].type == ?u29) 1 else std.mem.Alignment.@"1";
+            if (allocator.allocWithOptions(u8, size, alignment, null)) |p| break :blk p
             else |_| {}
             ui.oom();
         };
@@ -217,19 +218,20 @@ pub const Dir = extern struct {
         suberr: bool = false,
     };
 
-    pub fn fmtPath(self: *const @This(), withRoot: bool, out: *std.ArrayList(u8)) void {
+    pub fn fmtPath(self: *const @This(), alloc: std.mem.Allocator, withRoot: bool, out: *std.ArrayListUnmanaged(u8)) void {
         if (!withRoot and self.parent == null) return;
-        var components = std.ArrayList([:0]const u8).init(main.allocator);
-        defer components.deinit();
+        var components: std.ArrayListUnmanaged([:0]const u8) = .empty;
+        defer components.deinit(main.allocator);
         var it: ?*const @This() = self;
         while (it) |e| : (it = e.parent)
             if (withRoot or e.parent != null)
-                components.append(e.entry.name()) catch unreachable;
+                components.append(main.allocator, e.entry.name()) catch unreachable;
 
         var i: usize = components.items.len-1;
         while (true) {
-            if (i != components.items.len-1 and !(out.items.len != 0 and out.items[out.items.len-1] == '/')) out.append('/') catch unreachable;
-            out.appendSlice(components.items[i]) catch unreachable;
+            if (i != components.items.len-1 and !(out.items.len != 0 and out.items[out.items.len-1] == '/'))
+                out.append(main.allocator, '/') catch unreachable;
+            out.appendSlice(alloc, components.items[i]) catch unreachable;
             if (i == 0) break;
             i -= 1;
         }
@@ -271,11 +273,11 @@ pub const Link = extern struct {
 
     // Return value should be freed with main.allocator.
     pub fn path(self: *const @This(), withRoot: bool) [:0]const u8 {
-        var out = std.ArrayList(u8).init(main.allocator);
-        self.parent.fmtPath(withRoot, &out);
-        out.append('/') catch unreachable;
-        out.appendSlice(self.entry.name()) catch unreachable;
-        return out.toOwnedSliceSentinel(0) catch unreachable;
+        var out: std.ArrayListUnmanaged(u8) = .empty;
+        self.parent.fmtPath(main.allocator, withRoot, &out);
+        out.append(main.allocator, '/') catch unreachable;
+        out.appendSlice(main.allocator, self.entry.name()) catch unreachable;
+        return out.toOwnedSliceSentinel(main.allocator, 0) catch unreachable;
     }
 
     // Add this link to the inodes map and mark it as 'uncounted'.
@@ -350,7 +352,7 @@ pub const Ext = extern struct {
 pub const devices = struct {
     var lock = std.Thread.Mutex{};
     // id -> dev
-    pub var list = std.ArrayList(u64).init(main.allocator);
+    pub var list: std.ArrayListUnmanaged(u64) = .empty;
     // dev -> id
     var lookup = std.AutoHashMap(u64, DevId).init(main.allocator);
 
@@ -361,7 +363,7 @@ pub const devices = struct {
         if (!d.found_existing) {
             if (list.items.len >= std.math.maxInt(DevId)) ui.die("Maximum number of device identifiers exceeded.\n", .{});
             d.value_ptr.* = @as(DevId, @intCast(list.items.len));
-            list.append(dev) catch unreachable;
+            list.append(main.allocator, dev) catch unreachable;
         }
         return d.value_ptr.*;
     }

src/scan.zig

@@ -46,14 +46,24 @@ fn truncate(comptime T: type, comptime field: anytype, x: anytype) std.meta.fiel
 }
 
 
-fn statAt(parent: std.fs.Dir, name: [:0]const u8, follow: bool, symlink: *bool) !sink.Stat {
-    const stat = try std.posix.fstatatZ(parent.fd, name, if (follow) 0 else std.posix.AT.SYMLINK_NOFOLLOW);
-    symlink.* = std.posix.S.ISLNK(stat.mode);
+pub fn statAt(parent: std.fs.Dir, name: [:0]const u8, follow: bool, symlink: ?*bool) !sink.Stat {
+    // std.posix.fstatatZ() in Zig 0.14 is not suitable due to https://github.com/ziglang/zig/issues/23463
+    var stat: std.c.Stat = undefined;
+    if (std.c.fstatat(parent.fd, name, &stat, if (follow) 0 else std.c.AT.SYMLINK_NOFOLLOW) != 0) {
+        return switch (std.c._errno().*) {
+            @intFromEnum(std.c.E.NOENT) => error.FileNotFound,
+            @intFromEnum(std.c.E.NAMETOOLONG) => error.NameTooLong,
+            @intFromEnum(std.c.E.NOMEM) => error.OutOfMemory,
+            @intFromEnum(std.c.E.ACCES) => error.AccessDenied,
+            else => error.Unexpected,
+        };
+    }
+    if (symlink) |s| s.* = std.c.S.ISLNK(stat.mode);
     return sink.Stat{
         .etype =
-            if (std.posix.S.ISDIR(stat.mode)) .dir
+            if (std.c.S.ISDIR(stat.mode)) .dir
             else if (stat.nlink > 1) .link
-            else if (!std.posix.S.ISREG(stat.mode)) .nonreg
+            else if (!std.c.S.ISREG(stat.mode)) .nonreg
             else .reg,
         .blocks = clamp(sink.Stat, .blocks, stat.blocks),
         .size = clamp(sink.Stat, .size, stat.size),
@@ -81,7 +91,7 @@ fn isCacheDir(dir: std.fs.Dir) bool {
     const f = dir.openFileZ("CACHEDIR.TAG", .{}) catch return false;
     defer f.close();
     var buf: [sig.len]u8 = undefined;
-    const len = f.reader().readAll(&buf) catch return false;
+    const len = f.readAll(&buf) catch return false;
     return len == sig.len and std.mem.eql(u8, &buf, sig);
 }
 
@@ -174,7 +184,7 @@ const Thread = struct {
     thread_num: usize,
     sink: *sink.Thread,
     state: *State,
-    stack: std.ArrayList(*Dir) = std.ArrayList(*Dir).init(main.allocator),
+    stack: std.ArrayListUnmanaged(*Dir) = .empty,
     thread: std.Thread = undefined,
     namebuf: [4096]u8 = undefined,
 
@@ -255,13 +265,13 @@ const Thread = struct {
         const s = dir.sink.addDir(t.sink, name, &stat);
         const ndir = Dir.create(edir, stat.dev, dir.pat.enter(name), s);
         if (main.config.threads == 1 or !t.state.tryPush(ndir))
-            t.stack.append(ndir) catch unreachable;
+            t.stack.append(main.allocator, ndir) catch unreachable;
     }
 
     fn run(t: *Thread) void {
-        defer t.stack.deinit();
+        defer t.stack.deinit(main.allocator);
         while (t.state.waitPop()) |dir| {
-            t.stack.append(dir) catch unreachable;
+            t.stack.append(main.allocator, dir) catch unreachable;
 
             while (t.stack.items.len > 0) {
                 const d = t.stack.items[t.stack.items.len - 1];

src/sink.zig

@@ -140,20 +140,21 @@ pub const Dir = struct {
     }
 
     fn path(d: *Dir) [:0]u8 {
-        var components = std.ArrayList([]const u8).init(main.allocator);
-        defer components.deinit();
+        var components: std.ArrayListUnmanaged([]const u8) = .empty;
+        defer components.deinit(main.allocator);
         var it: ?*Dir = d;
-        while (it) |e| : (it = e.parent) components.append(e.name) catch unreachable;
+        while (it) |e| : (it = e.parent) components.append(main.allocator, e.name) catch unreachable;
 
-        var out = std.ArrayList(u8).init(main.allocator);
+        var out: std.ArrayListUnmanaged(u8) = .empty;
         var i: usize = components.items.len-1;
         while (true) {
-            if (i != components.items.len-1 and !(out.items.len != 0 and out.items[out.items.len-1] == '/')) out.append('/') catch unreachable;
-            out.appendSlice(components.items[i]) catch unreachable;
+            if (i != components.items.len-1 and !(out.items.len != 0 and out.items[out.items.len-1] == '/'))
+                out.append(main.allocator, '/') catch unreachable;
+            out.appendSlice(main.allocator, components.items[i]) catch unreachable;
             if (i == 0) break;
             i -= 1;
         }
-        return out.toOwnedSliceSentinel(0) catch unreachable;
+        return out.toOwnedSliceSentinel(main.allocator, 0) catch unreachable;
     }
 
     fn ref(d: *Dir) void {
@@ -291,7 +292,7 @@ fn drawConsole() void {
         var ansi: ?bool = null;
         var lines_written: usize = 0;
     };
-    const stderr = std.io.getStdErr();
+    const stderr = if (@hasDecl(std.io, "getStdErr")) std.io.getStdErr() else std.fs.File.stderr();
     const ansi = st.ansi orelse blk: {
         const t = stderr.supportsAnsiEscapeCodes();
         st.ansi = t;
@@ -450,25 +451,28 @@ pub fn draw() void {
     switch (main.config.scan_ui.?) {
         .none => {},
         .line => drawConsole(),
-        .full => switch (global.state) {
-            .done => {},
-            .err => drawError(),
-            .zeroing => {
-                const box = ui.Box.create(4, ui.cols -| 5, "Initializing");
-                box.move(2, 2);
-                ui.addstr("Clearing directory counts...");
-            },
-            .hlcnt => {
-                const box = ui.Box.create(4, ui.cols -| 5, "Finalizing");
-                box.move(2, 2);
-                ui.addstr("Counting hardlinks... ");
-                if (model.inodes.add_total > 0) {
-                    ui.addnum(.default, model.inodes.add_done);
-                    ui.addstr(" / ");
-                    ui.addnum(.default, model.inodes.add_total);
-                }
-            },
-            .running => drawProgress(),
+        .full => {
+            ui.init();
+            switch (global.state) {
+                .done => {},
+                .err => drawError(),
+                .zeroing => {
+                    const box = ui.Box.create(4, ui.cols -| 5, "Initializing");
+                    box.move(2, 2);
+                    ui.addstr("Clearing directory counts...");
+                },
+                .hlcnt => {
+                    const box = ui.Box.create(4, ui.cols -| 5, "Finalizing");
+                    box.move(2, 2);
+                    ui.addstr("Counting hardlinks... ");
+                    if (model.inodes.add_total > 0) {
+                        ui.addnum(.default, model.inodes.add_done);
+                        ui.addstr(" / ");
+                        ui.addnum(.default, model.inodes.add_total);
+                    }
+                },
+                .running => drawProgress(),
+            }
         },
     }
 }

src/ui.zig

@@ -17,8 +17,7 @@ pub var cols: u32 = undefined;
 
 pub fn die(comptime fmt: []const u8, args: anytype) noreturn {
     deinit();
-    const stderr = std.io.getStdErr();
-    stderr.writer().print(fmt, args) catch {};
+    std.debug.print(fmt, args);
     std.process.exit(1);
 }
 
@@ -27,6 +26,8 @@ pub fn quit() noreturn {
     std.process.exit(0);
 }
 
+const sleep = if (@hasDecl(std.time, "sleep")) std.time.sleep else std.Thread.sleep;
+
 // Should be called when malloc fails. Will show a message to the user, wait
 // for a second and return to give it another try.
 // Glitch: this function may be called while we're in the process of drawing
@@ -41,14 +42,13 @@ pub fn oom() void {
     if (main_thread == std.Thread.getCurrentId()) {
         const haveui = inited;
         deinit();
-        const stderr = std.io.getStdErr();
-        stderr.writeAll("\x1b7\x1b[JOut of memory, trying again in 1 second. Hit Ctrl-C to abort.\x1b8") catch {};
-        std.time.sleep(std.time.ns_per_s);
+        std.debug.print("\x1b7\x1b[JOut of memory, trying again in 1 second. Hit Ctrl-C to abort.\x1b8", .{});
+        sleep(std.time.ns_per_s);
         if (haveui)
             init();
     } else {
         _ = oom_threads.fetchAdd(1, .monotonic);
-        std.time.sleep(std.time.ns_per_s);
+        sleep(std.time.ns_per_s);
         _ = oom_threads.fetchSub(1, .monotonic);
     }
 }
@@ -80,7 +80,7 @@ pub fn errorString(e: anyerror) [:0]const u8 {
     };
 }
 
-var to_utf8_buf = std.ArrayList(u8).init(main.allocator);
+var to_utf8_buf: std.ArrayListUnmanaged(u8) = .empty;
 
 fn toUtf8BadChar(ch: u8) bool {
     return switch (ch) {
@@ -107,19 +107,19 @@ pub fn toUtf8(in: [:0]const u8) [:0]const u8 {
         if (std.unicode.utf8ByteSequenceLength(in[i])) |cp_len| {
             if (!toUtf8BadChar(in[i]) and i + cp_len <= in.len) {
                 if (std.unicode.utf8Decode(in[i .. i + cp_len])) |_| {
-                    to_utf8_buf.appendSlice(in[i .. i + cp_len]) catch unreachable;
+                    to_utf8_buf.appendSlice(main.allocator, in[i .. i + cp_len]) catch unreachable;
                     i += cp_len;
                     continue;
                 } else |_| {}
             }
         } else |_| {}
-        to_utf8_buf.writer().print("\\x{X:0>2}", .{in[i]}) catch unreachable;
+        to_utf8_buf.writer(main.allocator).print("\\x{X:0>2}", .{in[i]}) catch unreachable;
         i += 1;
     }
-    return util.arrayListBufZ(&to_utf8_buf);
+    return util.arrayListBufZ(&to_utf8_buf, main.allocator);
 }
 
-var shorten_buf = std.ArrayList(u8).init(main.allocator);
+var shorten_buf: std.ArrayListUnmanaged(u8) = .empty;
 
 // Shorten the given string to fit in the given number of columns.
 // If the string is too long, only the prefix and suffix will be printed, with '...' in between.
@@ -150,8 +150,8 @@ pub fn shorten(in: [:0]const u8, max_width: u32) [:0] const u8 {
     if (total_width <= max_width) return in;
 
     shorten_buf.shrinkRetainingCapacity(0);
-    shorten_buf.appendSlice(in[0..prefix_end]) catch unreachable;
-    shorten_buf.appendSlice("...") catch unreachable;
+    shorten_buf.appendSlice(main.allocator, in[0..prefix_end]) catch unreachable;
+    shorten_buf.appendSlice(main.allocator, "...") catch unreachable;
 
     var start_width: u32 = prefix_width;
     var start_len: u32 = prefix_end;
@@ -163,11 +163,11 @@ pub fn shorten(in: [:0]const u8, max_width: u32) [:0] const u8 {
         start_width += cp_width;
         start_len += cp_len;
         if (total_width - start_width <= max_width - prefix_width - 3) {
-            shorten_buf.appendSlice(in[start_len..]) catch unreachable;
+            shorten_buf.appendSlice(main.allocator, in[start_len..]) catch unreachable;
             break;
         }
     }
-    return util.arrayListBufZ(&shorten_buf);
+    return util.arrayListBufZ(&shorten_buf, main.allocator);
 }
 
 fn shortenTest(in: [:0]const u8, max_width: u32, out: [:0]const u8) !void {
@@ -335,8 +335,7 @@ fn updateSize() void {
 fn clearScr() void {
     // Send a "clear from cursor to end of screen" instruction, to clear a
     // potential line left behind from scanning in -1 mode.
-    const stderr = std.io.getStdErr();
-    stderr.writeAll("\x1b[J") catch {};
+    std.debug.print("\x1b[J", .{});
 }
 
 pub fn init() void {
@@ -634,7 +633,7 @@ pub fn getch(block: bool) i32 {
         }
         if (ch == c.ERR) {
             if (!block) return 0;
-            std.time.sleep(10*std.time.ns_per_ms);
+            sleep(10*std.time.ns_per_ms);
             continue;
         }
         return ch;
@@ -642,3 +641,50 @@ pub fn getch(block: bool) i32 {
     die("Error reading keyboard input, assuming TTY has been lost.\n(Potentially nonsensical error message: {s})\n",
         .{ c.strerror(@intFromEnum(std.posix.errno(-1))) });
 }
+
+fn waitInput() void {
+    if (@hasDecl(std.io, "getStdIn")) {
+        std.io.getStdIn().reader().skipUntilDelimiterOrEof('\n') catch unreachable;
+    } else {
+        var buf: [512]u8 = undefined;
+        var rd = std.fs.File.stdin().reader(&buf);
+        _ = rd.interface.discardDelimiterExclusive('\n') catch unreachable;
+    }
+}
+
+pub fn runCmd(cmd: []const []const u8, cwd: ?[]const u8, env: *std.process.EnvMap, reporterr: bool) void {
+    deinit();
+    defer init();
+
+    // NCDU_LEVEL can only count to 9, keeps the implementation simple.
+    if (env.get("NCDU_LEVEL")) |l|
+        env.put("NCDU_LEVEL", if (l.len == 0) "1" else switch (l[0]) {
+            '0'...'8' => |d| &[1] u8{d+1},
+            '9' => "9",
+            else => "1"
+        }) catch unreachable
+    else
+        env.put("NCDU_LEVEL", "1") catch unreachable;
+
+    var child = std.process.Child.init(cmd, main.allocator);
+    child.cwd = cwd;
+    child.env_map = env;
+
+    const term = child.spawnAndWait() catch |e| blk: {
+        std.debug.print("Error running command: {s}\n\nPress enter to continue.\n", .{ ui.errorString(e) });
+        waitInput();
+        break :blk std.process.Child.Term{ .Exited = 0 };
+    };
+
+    const n = switch (term) {
+        .Exited  => "error",
+        .Signal  => "signal",
+        .Stopped => "stopped",
+        .Unknown => "unknown",
+    };
+    const v = switch (term) { inline else => |v| v };
+    if (term != .Exited or (reporterr and v != 0)) {
+        std.debug.print("\nCommand returned with {s} code {}.\nPress enter to continue.\n", .{ n, v });
+        waitInput();
+    }
+}

src/util.zig

@@ -32,8 +32,8 @@ pub fn blocksToSize(b: u64) u64 {
 // Ensure the given arraylist buffer gets zero-terminated and returns a slice
 // into the buffer. The returned buffer is invalidated whenever the arraylist
 // is freed or written to.
-pub fn arrayListBufZ(buf: *std.ArrayList(u8)) [:0]const u8 {
-    buf.append(0) catch unreachable;
+pub fn arrayListBufZ(buf: *std.ArrayListUnmanaged(u8), alloc: std.mem.Allocator) [:0]const u8 {
+    buf.append(alloc, 0) catch unreachable;
     defer buf.items.len -= 1;
     return buf.items[0..buf.items.len-1:0];
 }
@@ -196,5 +196,54 @@ pub fn expanduser(path: []const u8, alloc: std.mem.Allocator) ![:0]u8 {
     const home = std.mem.trimRight(u8, home_raw, "/");
 
     if (home.len == 0 and path.len == len) return alloc.dupeZ(u8, "/");
-    return try std.fmt.allocPrintZ(alloc, "{s}{s}", .{ home, path[len..] });
+    return try std.mem.concatWithSentinel(alloc, u8, &.{ home, path[len..] }, 0);
 }
+
+
+// Silly abstraction to read a file one line at a time. Only exists to help
+// with supporting both Zig 0.14 and 0.15, can be removed once 0.14 support is
+// dropped.
+pub const LineReader = if (@hasDecl(std.io, "bufferedReader")) struct {
+    rd: std.io.BufferedReader(4096, std.fs.File.Reader),
+    fbs: std.io.FixedBufferStream([]u8),
+
+    pub fn init(f: std.fs.File, buf: []u8) @This() {
+        return .{
+            .rd = std.io.bufferedReader(f.reader()),
+            .fbs = std.io.fixedBufferStream(buf),
+        };
+    }
+
+    pub fn read(s: *@This()) !?[]u8 {
+        s.fbs.reset();
+        s.rd.reader().streamUntilDelimiter(s.fbs.writer(), '\n', s.fbs.buffer.len) catch |err| switch (err) {
+            error.EndOfStream => if (s.fbs.getPos() catch unreachable == 0) return null,
+            else => |e| return e,
+        };
+        return s.fbs.getWritten();
+    }
+
+} else struct {
+    rd: std.fs.File.Reader,
+
+    pub fn init(f: std.fs.File, buf: []u8) @This() {
+        return .{ .rd = f.readerStreaming(buf) };
+    }
+
+    pub fn read(s: *@This()) !?[]u8 {
+        // Can't use takeDelimiter() because that's not available in 0.15.1,
+        // Can't use takeDelimiterExclusive() because that changed behavior in 0.15.2.
+        const r = &s.rd.interface;
+        const result = r.peekDelimiterInclusive('\n') catch |err| switch (err) {
+            error.EndOfStream => {
+                const remaining = r.buffer[r.seek..r.end];
+                if (remaining.len == 0) return null;
+                r.toss(remaining.len);
+                return remaining;
+            },
+            else => |e| return e,
+        };
+        r.toss(result.len);
+        return result[0 .. result.len - 1];
+    }
+};