Viewing files

Peach Commander has a built-in viewer that lets you look inside a file without opening another app or changing the file. Press F3 on the item under the cursor and the viewer opens instantly, even for very large files. It automatically chooses the best way to show the content: readable text, syntax-colored code, a raw hex dump, or a full-size image. You can also preview a file right inside the window using Quick View, or hand it to macOS Quick Look.

View a file

1. Move the cursor onto a file in the active panel.
2. Press F3 (or choose View in the File menu). The viewer opens in its own window.
3. Use the toolbar to switch how the content is shown: Text, Code, Hex, Image, or Rendered. Leave it on the automatic setting to let Peach Commander decide.
4. Scroll with the arrow keys, Page Up/Page Down, and the scroll bar. For long text, turn on the minimap button to see and jump around the whole file at a glance.
5. Press N to jump to the next selected file, or close the window with Esc.

(Figure: Viewing a text file, with the representation picker and minimap in the toolbar.)

Find text and change the encoding

• Press Ctrl+F to search within the file. Press F3 to jump to the next match and Shift+F3 for the previous one.
• If text looks garbled, click Encoding in the toolbar (or press E) to cycle through text encodings until it reads correctly; the automatic setting usually gets it right.
• Press W to toggle word wrap for long lines.

Notes about a line

If the Notes plugin is installed, a note can be about a particular line of a file rather than about the file as a whole.

• Put the cursor on the line and choose View ▸ Note for This Line… (Cmd+Shift+N). The note editor opens with the file name and the line number in its title.
• Lines that already carry a note appear as a Notes group in the marks panel at the bottom of the window, next to any search marks. Press Cmd+Ctrl+M to open the panel; double-click an entry to jump to that line.
• The notes themselves live with all your other notes, so the notes overview and Find Files find them the same way. Deleting one is done in the note editor — the panel's close button only hides the group.

Quick View and Quick Look

Quick View shows a live preview in the panel you are not using, so you can keep browsing on one side while previewing on the other.

1. Press Ctrl+Q. The inactive panel turns into a preview area.
2. Move the cursor over different files in the active panel to preview each one.
3. Press Ctrl+Q again, or Esc, to return the panel to a normal file list.

For a fast full-screen preview handled by macOS itself, press Cmd+Y (Quick Look). Press Cmd+Y or Space again to close it.

The Info side panel

The side panel (View > Preview Panel, or Cmd+Shift+P) has an Info page that shows the item under the cursor the way Finder's info sidebar does.

• The preview fills the width of the panel, so widen the panel and the preview grows with it. Drag the panel's left edge to make it wider or narrower; the width is remembered.
• It is a real macOS preview, not a small thumbnail: every format Quick Look can show works here, and a multi-page document scrolls page by page inside the preview.
• Below it are the name, the kind and the size, then when the item was created and changed and which folder it is in.

Moving the cursor updates the name and details immediately; the preview itself follows a moment later, so holding an arrow key through a long folder does not start a preview for every row it passes.

Decompile Java class files

With the Java Decompiler plugin switched on, F3 on a .class file shows readable code instead of binary — including class files inside a JAR or ZIP, which you can step into and view without unpacking.

The plugin contains no decompiler of its own. It drives an engine you install, and you can swap engines at any time:

• CFR (MIT licence) and Vineflower (Apache 2.0) produce Java source. Put cfr.jar or vineflower.jar into the engine folder.
• Procyon (Apache 2.0) is a third source decompiler.
• javap needs no download at all — it comes with any JDK, and shows bytecode rather than Java source.

Nothing is downloaded for you: these are third-party programs under their own licences, and Peach Commander neither fetches nor updates them. The viewer's Engine Folder… button opens the folder they belong in and leaves a note there naming each engine and where to get it. All of them except javap need Java installed.

Switch engines with the menu at the top of the viewer; the one you pick is used immediately and the result is kept, so comparing two engines on the same file is instant.

The source is syntax-highlighted, and two buttons take it further: Save As… writes it to a file, and Open in Editor hands it to whatever opens .java on your Mac. A very large result is shown unhighlighted so that it appears at once rather than after a pause; the status line says when that happens.

Results are cached on disk, so reopening a file you looked at before is instant; the cache is keyed by the file's size and date and by the engine's arguments, so a rebuilt class or a changed flag is decompiled again. The engine you pick is remembered per file kind. A profile can inherit from a built-in with extends = cfr and override only the flags — useful when you keep two presets of the same engine.

Turn on Compare to open a second panel with its own engine menu. Two decompilers fail in different places, so seeing them side by side is often quicker than deciding which to trust; picking javap on one side puts the bytecode next to the source. Both panels share the cache, so switching between engines you have already run is instant.

F3 on a whole .jar, .apk or .dex decompiles all of it at once and shows a package tree beside the source. The search field above the tree searches every class, which is the question a single class cannot answer: where a string, a call or a constant actually occurs, when you do not yet know which class holds it. Matches narrow the tree and the first one opens at its line. Opening a JAR with Enter still browses it as an archive — the two verbs stay separate.

There is a second, more direct route: put the cursor on a .class file or a whole archive and choose Decompile to Sources (Commands menu, the context menu, or ⌘⇧J). The classes are decompiled and the result opens in the other file panel as ordinary .java files. From there the whole file manager applies — F3 views them with Peach Commander's own Java highlighting, Alt+F7 searches across them, F5 copies them out, and you can compare or tag them like anything else. For most work this beats a window of its own, which is why the plugin's own tree can be switched off in Settings ▸ Decompiler.

A second plugin does the same for .NET: F3 on a managed .dll, .exe or .winmd shows its types as C#, Decompile Assembly to Sources (⌘⇧N) puts them in a file panel, and the search can look inside an assembly the same way. It drives ILSpy (MIT, dotnet tool install -g ilspycmd) for source, or monodis from Mono for IL — the .NET counterpart to javap. A native .dll has the same extension and no source to show, so the plugin checks before it opens and leaves those to the built-in viewer.

The settings page has a Check Engines button, and it is worth pressing: “installed” elsewhere only means the file is on disk, and a Java engine on a Mac without a JDK is present and cannot run. The check asks each engine for its version and says which ones actually work.

Android is covered too: F3 on a .dex file uses jadx (Apache 2.0, brew install jadx), which turns Dalvik bytecode back into Java. Adding it took one engine description — the same mechanism, a different format.

The plugin is off until you turn it on, in Settings ▸ Plugins — most people never open a class file, and it needs an engine to be useful.

To add an engine of your own, create decompilers.ini in the engine folder:

[myengine]
name   = My Decompiler
kinds  = class
tool   = java
args    = -jar {engine} {input}
engine  = my-decompiler.jar   ; a bare name is looked up in this folder
output  = stdout
timeout = 30                  ; seconds before the engine is stopped

{input}, {engine} and {outdir} are filled in when the engine runs. Your own entries take precedence over the built-in ones, and reusing a built-in name (cfr, vineflower, procyon, javap) replaces it rather than adding a second entry.

Shortcuts

Action	Shortcut
View file under cursor	F3
View only the file under cursor (ignore marked files)	Shift+F3
Open in an external viewer	Option+F3
Find within the viewer	Ctrl+F
Note for the line under the cursor	Cmd+Shift+N
Show or hide the marks panel	Cmd+Ctrl+M
Next / previous match	F3 / Shift+F3
Quick View in the other panel	Ctrl+Q
Quick Look (macOS preview)	Cmd+Y
Close the viewer or Quick View	Esc

Notes

• The viewer is read-only. To change a file, use the editor instead (see Editing files).
• Very large files open without delay: text opens a fast, scrollable view and the hex view streams straight from disk at any size.
• Press F3 on a folder to see a summary of its contents and total size instead of file bytes.
• The Rendered mode displays formatted content such as web pages and Markdown; hex mode shows the raw bytes side by side with their characters, which is handy for inspecting binary files.
• In Rendered mode you can select text and copy it, and Find searches the rendered page. Buttons that cannot apply to a rendered page — Format, Encoding, Mark All, Marks and Go To — are greyed out rather than doing nothing.
• The Format button re-indents structured files (JSON, XML, HTML, INI, YAML, and more when you have the matching command-line tool installed). It is described in full under Editing files, and works the same way here.