Native /view: read-only viewer for files and completed output (#397)

CHANGELOG.md

@@ -6,6 +6,11 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
 ## [Unreleased]
 
+### Added
+
+- **`/view`, a native read-only viewer** for files and completed output ([#397](https://github.com/raiseCatError/notMyShell/issues/397)). `/view README.md` opens a file relative to the shell's directory (`~` for home): Markdown renders (`m` shows the source), source files get syntax colors and line numbers, `.diff`/`.patch` files and `git diff`/`git show` output read as diffs. `/view N` opens completed output N (numbered as `/copy` numbers it) and `/view` the latest; Actions → View output does the same for a block. Find with `/` and `n`/`N`, go to a line with `:`, `w` toggles wrapping (Left/Right scroll sideways), `l` line numbers, `c` copies the whole text, Esc closes. Viewing never changes the file or the transcript.
+  - Limits: regular files only (directories, devices and pipes are refused), at most 8 MiB and 200,000 lines (the rest is named, with `less` or an editor as the way to read it), binary and UTF-16 files are refused, invalid UTF-8 is shown with `�` and a note. Control characters, escape sequences and invisible format characters are shown as visible marks, never interpreted. Open in pager, `less`, `bat` and Glow are unchanged.
+
 ### Fixed
 
 - Multi-line progress displays that redraw their own rows (cursor up and erase line, as concurrent downloads and container pulls do) now update in place instead of leaving a copy of every frame in the transcript ([#388](https://github.com/raiseCatError/notMyShell/issues/388)). A program can redraw only its own recent rows, at most a screen height up, never NMSh's lines or earlier commands; `/copy` copies the final rows once. Absolute cursor positioning keeps the previous behavior.

docs/development/v021-ledger.md

@@ -16,7 +16,7 @@ Automated results here are not physical-terminal validation.
 | --- | --- | --- | --- | --- | --- |
 | 0 | Design and ledger | #410 | `docs/v021-design` / #411 | | PR open, CI green; awaiting merge |
 | 1 | Reliability gates | #403, #408, #388 | `fix/v021-reliability` (stacked on #411) | | PR open |
-| 2 | `/view` | #397, #402 | | | |
+| 2 | `/view` | #397, #402 | `feature/v021-view` (stacked on slice 1) | | PR open |
 | 3 | `/edit` | #402 | | | |
 | 4 | Semantic Output | #386 | | | |
 | 5 | `/track` | #393 (#394) | | | |
@@ -34,7 +34,8 @@ Automated results here are not physical-terminal validation.
 ## Physical QA still required
 
 Checklist: [v0.21 physical QA](../testing/v021-physical-qa.md). Slice 1: section 1 (multi-row progress in Ghostty
-and Terminal.app, queued highlight colors).
+and Terminal.app, queued highlight colors). Slice 2: section 2 (`/view` keys, rendering, refusals, hostile text,
+NO_COLOR).
 
 ## Verification notes
 

docs/testing/v021-physical-qa.md

@@ -16,6 +16,8 @@
 |---|---|---|---|---|---|---|
 | 1 Multi-row progress (#388) | Ghostty | macOS | zsh | | Not run | |
 | 1 Multi-row progress (#388) | Terminal.app | macOS | Bash or Fish | | Not run | |
+| 2 `/view` | Ghostty | macOS | zsh | | Not run | |
+| 2 `/view` | Terminal.app | macOS | zsh | | Not run | |
 
 ## 1. Multi-row progress redraws (#388)
 
@@ -29,3 +31,22 @@
 - [ ] 1.6 `vim`, `less` and `htop` still take the full screen and return to the composer.
 - [ ] 1.7 Queue two quick commands (`ls` then `pwd`) with Ctrl+Q while a short command runs: both stored command
   lines end with the known-command color (#408).
+
+## 2. Native viewer (`/view`, View output)
+
+- [ ] 2.1 `/view README.md` in this repository: Markdown is rendered (headings, lists, code, tables); `m` shows the
+  source with line numbers; `m` again returns.
+- [ ] 2.2 `/view src/viewer/ViewerPanel.ts`: syntax colors, line numbers, `w` turns wrapping off and Left/Right scroll
+  sideways with `‹`/`›` marks, `l` hides numbers.
+- [ ] 2.3 `/` finds text (lowercase ignores case), `n`/`N` step and wrap with a note, `:` + number goes to a line,
+  `G`/`g` end and start, PageUp/PageDown, mouse wheel scrolls.
+- [ ] 2.4 Run `seq 1 5000`, then `/view` (latest output) and Actions → View output on that block; `/view 2` opens the
+  previous output. The transcript is unchanged after closing.
+- [ ] 2.5 `c` copies the whole document; the clipboard has the exact text (tabs kept), and nothing else.
+- [ ] 2.6 Hostile content: `printf '\033]8;;https://example.com\a\033[31mred\033[2J\n' > /tmp/h.txt && /view /tmp/h.txt`
+  shows `␛` marks, no color change, no link, no screen clear.
+- [ ] 2.7 Refusals say why: a directory, a missing file, `/dev/zero`, a FIFO (`mkfifo /tmp/f && /view /tmp/f` returns
+  at once), a binary (`/view /bin/ls`), a 20 MB log (shows the first 8 MiB with a note).
+- [ ] 2.8 Esc closes, the composer draft and cursor are where they were, and a running command's output kept
+  arriving underneath. At 32×10 the viewer still fits and Esc is shown.
+- [ ] 2.9 `NO_COLOR=1` and Safe glyphs: matches and the current match are still visible (reverse video).

src/app/TerminalApp.ts

@@ -68,6 +68,8 @@ import {DEFAULT_REPORT_OPTIONS, describeFindings, redactText, scanSensitive, typ
 import {applyReportEdit, createReportReview, createTextReview, renderReportReview, reportReviewKey, type ReportReviewState} from '../ui/ReportReview.js';
 import {configuredEditor} from '../host/HostActions.js';
 import {comparePanelKey, createComparePanel, renderComparePanel, type ComparePanelState} from '../ui/ComparePanel.js';
+import {loadFileDocument, outputDocument} from '../viewer/document.js';
+import {createViewer, renderViewer, viewerKey, type ViewerLook, type ViewerState} from '../viewer/ViewerPanel.js';
 import {buildComparisonReport, copyableDiff, previousRun} from '../output/compare.js';
 import {createStripStudio, renderStripStudio, stripStudioKey, type StripStudioState} from '../status/StripStudio.js';
 import {configureListKey, renderConfigureList, type ConfigureListState} from '../tools/config/ConfigureList.js';
@@ -1620,6 +1622,17 @@ export class TerminalApp {
       this.render();
       return;
     }
+    if (this.viewer) {
+      const viewer = this.viewer;
+      const {columns, rows} = this.dimensions();
+      const action = viewerKey(viewer, key, columns, rows - 4, this.viewerLook());
+      if (action?.kind === 'close') { this.viewer = undefined; this.returnFromPanel(); }
+      else if (action?.kind === 'copy') {
+        void this.copyText(action.text, 'Copied the document').then(note => { if (note && this.viewer === viewer) { viewer.note = note; this.render(); } });
+      }
+      this.render();
+      return;
+    }
     if (this.comparePanel) {
       const {columns, rows} = this.dimensions();
       const action = comparePanelKey(this.comparePanel, key, columns, rows - 4);
@@ -2873,6 +2886,7 @@ export class TerminalApp {
       else this.configureClipboardChanges(slash.suggestions);
     }
     else if (slash.kind === 'pins') { this.panelOrigin = undefined; this.openPins(); }
+    else if (slash.kind === 'view') this.openViewer(slash.target, command.trim());
     else if (slash.kind === 'compare') {
       if (slash.error) this.output.addFrontendInteraction(command.trim(), slash.error, ERROR);
       else {
@@ -3230,6 +3244,7 @@ export class TerminalApp {
       try { await writeClipboard(record.command); this.noteClipboard(`Copied command · ${copyStats(record.command).characters.toLocaleString()} characters`, 'success'); }
       catch (error) { this.noteClipboard(clipboardFailure(error), 'error'); }
     } else if (action === 'fold') this.output.toggleExpanded(index);
+    else if (action === 'view') this.openOutputViewer(record);
     else if (action === 'pager') await this.openBlockInPager(record);
     else if (action === 'explain') { this.explainBlock = record.startId; this.openAsk('why did this fail'); }
     else if (action === 'edit' || action === 'rerun') {
@@ -3553,6 +3568,50 @@ export class TerminalApp {
     finally { rmSync(directory, {recursive: true, force: true}); this.render(); }
   }
 
+  private viewerLook(): ViewerLook {
+    return {syntax: this.syntaxSgr, hyperlinks: this.host.capabilities.hyperlinks};
+  }
+
+  /**
+   * /view: a completed output by its /copy number (the latest when no target is given), or a file relative to the
+   * shell's directory. The file is read asynchronously and read-only; a failure is reported in the transcript.
+   */
+  private openViewer(target: string, command: string): void {
+    this.viewerLoad?.abort();
+    this.viewerLoad = undefined;
+    if (!target || /^[1-9]\d{0,2}$/u.test(target)) {
+      const number = target ? Number(target) : 1;
+      const record = this.output.recentShellCommands()[number - 1];
+      if (!record) {
+        this.output.addFrontendInteraction(command, target ? `No completed command output at ${number}.` : 'No completed output yet. /view <file> opens a file.', target ? ERROR : INFO);
+        return;
+      }
+      this.openOutputViewer(record);
+      return;
+    }
+    const load = new AbortController();
+    this.viewerLoad = load;
+    void loadFileDocument(target, this.shellCwd, {signal: load.signal}).then(result => {
+      if (this.viewerLoad !== load || this.stopped) return;
+      this.viewerLoad = undefined;
+      if (!result.ok) { this.output.addFrontendInteraction(command, result.reason, ERROR); this.render(); return; }
+      // Another panel opened while the file was read: it keeps the keys; the file is not opened over it.
+      if (this.hasModalInput()) return;
+      this.panelOrigin = undefined;
+      this.viewer = createViewer(result.document);
+      this.render();
+    });
+  }
+
+  /** View output: the record's stored output, numbered as /copy numbers it. */
+  private openOutputViewer(record: CompletedCommand): void {
+    const number = this.output.recentShellCommands().indexOf(record) + 1;
+    this.panelOrigin = undefined;
+    // The text /copy copies (tabs as the program wrote them), without the optional completion status.
+    this.viewer = createViewer(outputDocument({command: record.command, output: recordCopyText(record, false), exitCode: record.exitCode}, Math.max(1, number)));
+    this.render();
+  }
+
   /** Compare output…: straight to the difference when the other side is known, otherwise choose it (previous run first). */
   private openCompare(base: CompletedCommand, partner?: CompletedCommand): void {
     this.panelOrigin = undefined;
@@ -4905,7 +4964,7 @@ export class TerminalApp {
   private get settingsPanelActive(): boolean { return this.hasModalInput(); }
 
   private hasModalInput(ignorePalette = false): boolean {
-    return Boolean(this.stopsEditor || this.chromeEditor || this.screensaverPanel || this.themeStudio || this.themeBridgePanel || this.rowPanel || this.copyPicker || this.summaryReview || this.reportReview || this.comparePanel || this.background.panel || this.batchReview || this.pinsPanel || this.stripStudio || this.configureList || this.tmuxPanel || this.dotfiles || this.setupState || this.installPrompt || this.presetPanel || this.toolsPanel || this.toolConfigurationLoading || this.toolConfiguration || this.promptPanelState || this.transcriptPanelState || this.providerPanelState || (!ignorePalette && this.paletteState) || this.syntaxPanelState || this.layoutPanelState || this.settingsPanelState
+    return Boolean(this.stopsEditor || this.chromeEditor || this.screensaverPanel || this.themeStudio || this.themeBridgePanel || this.rowPanel || this.copyPicker || this.summaryReview || this.reportReview || this.comparePanel || this.viewer || this.background.panel || this.batchReview || this.pinsPanel || this.stripStudio || this.configureList || this.tmuxPanel || this.dotfiles || this.setupState || this.installPrompt || this.presetPanel || this.toolsPanel || this.toolConfigurationLoading || this.toolConfiguration || this.promptPanelState || this.transcriptPanelState || this.providerPanelState || (!ignorePalette && this.paletteState) || this.syntaxPanelState || this.layoutPanelState || this.settingsPanelState
       || this.resumeBrowser || this.appearanceHub || this.keyboardState || this.startupPanel || this.aboutPanel || this.shellPanel || this.openPanel || this.askState || this.agentView || this.agentPanel || this.launcher || this.modsPanel || this.worktreePanel || this.githubPanel || this.providersOverview || this.understandingPanel || this.cursorPanel || this.doctorPanel || this.watchPanel || this.queuePanel || this.queueHistoryPanel || this.pasteReview || this.misePanel || this.keepAwakePanel);
   }
 
@@ -4947,6 +5006,7 @@ export class TerminalApp {
     if (this.summaryReview) return renderReportReview(this.summaryReview.document, columns, this.dimensions().rows - 4);
     if (this.reportReview) return renderReportReview(this.reportReview, columns, this.dimensions().rows - 4);
     if (this.comparePanel) return renderComparePanel(this.comparePanel, columns, this.dimensions().rows - 4);
+    if (this.viewer) return renderViewer(this.viewer, columns, this.dimensions().rows - 4, this.viewerLook());
     if (this.background.panel) return framePanel(this.background.panelRows(Math.max(1, columns - 4), this.dimensions().rows - 4,
       {now: Date.now(), color: colorLevel() !== 'none', safe: getCurrentGlyphMode() === 'safe'}), columns);
     if (this.rowPanel) return renderRowPanel(this.rowPanel, this.promptConfiguration, columns, this.dimensions().rows, this.rowPanelPreview(columns));
@@ -5875,6 +5935,10 @@ export class TerminalApp {
   private reportReview?: ReportReviewState;
   /** Compare output…: choosing the other block, then the difference. */
   private comparePanel?: ComparePanelState;
+  /** The native read-only viewer (/view, View output); owns keys while open. */
+  private viewer?: ViewerState;
+  /** A file /view is still reading; a newer request or Esc cancels it. */
+  private viewerLoad?: AbortController;
   private clipboardNote?: {text: string; tone: 'success' | 'info' | 'error'; until: number};
   private clipboardNoteTimer?: ReturnType<typeof setTimeout>;
   /** The block whose Copy control just succeeded (by startId), shown as "Copied" until `until`. */

src/ask/concepts.ts

@@ -253,6 +253,9 @@ export const CONCEPTS: readonly Concept[] = [
   {id: 'compare', label: 'Compare output', support: 'actionable', open: '/compare', covers: ['/compare'],
     aliases: ['compare output', 'compare outputs', 'diff output', 'compare runs', 'what changed between runs', 'compare with previous run'],
     description: '/compare shows what changed between two command outputs (by default the latest and the previous run of the same command; /compare N M picks them by /copy number). Also Actions → Compare output…. Added, removed and changed lines; c copies the diff, r a comparison report.'},
+  {id: 'view', label: 'View a file or output', support: 'actionable', open: '/view', covers: ['/view'],
+    aliases: ['view file', 'view a file', 'read a file', 'open a file read only', 'view output', 'read markdown', 'preview markdown', 'view log', 'pager'],
+    description: '/view opens a read-only native viewer: /view README.md for a file (Markdown renders; m shows the source), /view N for completed output N (numbered as /copy), /view alone for the latest output. Also Actions → View output. Find with /, n/N, go to a line with :, w wraps, l numbers, c copies the whole text. less, bat and Glow still work as usual.'},
   {id: 'paste-batch', label: 'Paste and queue a batch', support: 'actionable', open: '/ps', covers: ['/ps', '/clips'],
     aliases: ['paste commands', 'paste batch', 'paste from clipboard', 'queue pasted commands', 'review pasted commands', 'ps command', 'run as block'],
     description: '/ps reads the clipboard once and shows Paste Review. B reviews a safe batch with choices to run as one block, queue separately, edit or cancel; quotes, loops and heredocs stay whole. C deliberately keeps a clip in memory; /clips reviews it before insertion. Clips disappear when this frontend exits. Nothing executes automatically.'},
@@ -364,7 +367,7 @@ export const GUIDE_SECTIONS: readonly GuideSection[] = [
   {id: 'chroma', title: 'Chroma', why: 'Optional gradients and motion for NMSh-owned chrome only; your command output is never recolored.', concepts: ['chroma', 'effects', 'activity']},
   {id: 'shells', title: 'Shells', why: 'One NMSh window can run zsh, Fish or Bash, and you can leave for a plain shell and come back.', concepts: ['shell', 'leave', 'otherShells']},
   {id: 'completion', title: 'Completion & suggestions', why: 'Tab completion lists real candidates; ghost suggestions predict the rest of the line.', concepts: ['completion', 'suggestions']},
-  {id: 'history', title: 'History & transcripts', why: 'Find what you ran and what it printed, now or in earlier sessions.', concepts: ['history', 'picker', 'transcript', 'find', 'copy', 'output-actions', 'compare', 'transcripts', 'pins']},
+  {id: 'history', title: 'History & transcripts', why: 'Find what you ran and what it printed, now or in earlier sessions.', concepts: ['history', 'picker', 'transcript', 'find', 'copy', 'output-actions', 'view', 'compare', 'transcripts', 'pins']},
   {id: 'sessions', title: 'Sessions', why: 'Sessions keep running when a window closes; reattach, switch or get notified.', concepts: ['sessions', 'queue', 'agentSessions', 'presets', 'notices', 'commandNotifications', 'panes', 'keepAwake']},
   {id: 'ask', title: 'Ask', why: 'Plain-English help that knows NMSh, your commands and this repository, and never runs anything you did not confirm.', concepts: ['ask']},
   {id: 'intelligence', title: 'Local intelligence', why: 'An optional local model helps Ask map vague requests to known actions. It runs on this machine, never writes commands, and Ask works fully without it.', concepts: ['understanding'],

src/commands/slashCommands.ts

@@ -41,6 +41,7 @@ const RAW_COMMANDS: readonly SlashCommand[] = [
   {name: '/copy', insertion: '/copy', description: 'Select completed output: Up/Down, Enter copies, Esc returns (saved Quick Copy preferences still apply)'},
   {name: '/copy N', insertion: '/copy ', description: 'Copy Nth previous output; -N the latest N, A-B or 1,3,5 several; --status adds completion status'},
   {name: '/copy settings', insertion: '/copy settings', description: 'Output navigation, Quick Copy or Interactive Picker; completion status and auto-expand preferences'},
+  {name: '/view', insertion: '/view ', description: 'Read a file or a completed output in a native viewer: /view README.md · /view 2 (output 2, numbered as /copy) · /view (latest output)'},
   {name: '/compare', insertion: '/compare', description: 'Compare two outputs: /compare (latest with its previous run), /compare N, /compare N M (numbers as /copy)'},
   {name: '/pins', insertion: '/pins', description: 'Commands and recipes you kept: stage a pin, or review and queue a recipe (nothing runs by itself)'},
   {name: '/ps', insertion: '/ps', description: 'Paste from the clipboard, reviewed first: read when you run it, never in the background'},
@@ -168,6 +169,8 @@ export type ParsedSlashCommand =
   | {kind: 'pins'}
   /** /compare [A [B]]: outputs by /copy number; A defaults to the latest, B to A's previous run (or a choice). */
   | {kind: 'compare'; first?: number; second?: number; error?: string}
+  /** /view [path | N]: a file (relative to the shell's directory, ~ for home), output N as /copy numbers it, or the latest output. */
+  | {kind: 'view'; target: string}
   | {kind: 'appearance'}
   | {kind: 'motion'}
   | {kind: 'prompt'}
@@ -263,6 +266,8 @@ export function parseSlashCommand(input: string): ParsedSlashCommand | undefined
   const clips = /^\/clips(?:\s+suggestions\s+(on|off))?\s*$/u.exec(input);
   if (clips) return {kind: 'clips', ...(clips[1] ? {suggestions: clips[1] === 'on'} : {})};
   if (/^\/pins\s*$/u.test(input)) return {kind: 'pins'};
+  const view = /^\/view(?:\s+([\s\S]*))?$/u.exec(input);
+  if (view) return {kind: 'view', target: (view[1] ?? '').trim()};
   // /cp is /copy: one parser, one handler, every form.
   if (/^\/(?:copy|cp)\s+settings\s*$/u.test(input)) return {kind: 'copySettings'};
   const copy = /^\/(?:copy|cp)(?:\s+(.*))?$/su.exec(input);