Using Diffoniq from Other Programs

Most version control clients, file managers and IDEs let you plug in an external diff viewer. Diffoniq needs no plugin or adapter for this: started with exactly two path arguments, it opens that comparison straight away — for two files, two folders or two archives. A host that only ever expected a text diff can suddenly compare two ZIP files.

The recipe for your program

Host	Where to configure it	Arguments
Git (command line)	`.gitconfig`, section `[difftool "diffoniq"]`	`--read-only-left --no-backup "$LOCAL" "$REMOTE"`
TortoiseGit	Settings → Diff Viewer → External	`--read-only-left --no-backup %base %mine`
TortoiseSVN	Settings → External Programs → Diff Viewer	`--read-only-left --no-backup %base %mine`
JetBrains IDEs	Settings → Tools → Diff & Merge → External Diff Tools	`--read-only-left --no-backup %1 %2`
Visual Studio (TFVC)	Options → Source Control → Configure User Tools	`--read-only %1 %2`
Total Commander	`wincmd.ini`, section `[Configuration]`	none — it passes your real files
WinSCP	Commands → Custom Commands → Add	`"!^!" "!"` — no switch, see the page

Each entry links to the full walkthrough, including the one step that is easy to miss. Further hosts — SourceTree, SmartGit, Git Extensions, TortoiseHg, Perforce P4V — follow the same pattern with different placeholder names.

Which switches to use, and why

Many hosts do not hand you the real files. They extract a revision, or download a remote file, into a temporary copy. Diffoniq can edit and save, so a correction typed into such a copy is gone the moment the host cleans up — without a warning. This table is the whole rule:

What the host passes	Switches
Left a temporary copy, right your real working file (the usual case: comparing against the working tree)	`--read-only-left --no-backup`
Both sides temporary copies (comparing two stored revisions)	`--read-only`
Both sides real files (file managers, Explorer)	none — editing is what you want here

Why the second switch: when you save, Diffoniq keeps the original as a backup with .BAK appended, next to the file. Inside a working copy that is a new, unversioned file — your version control client reports it, and it is committed by accident easily enough. Where the repository is already your safety net, --no-backup takes it out of the way. Where nothing keeps history for you, leave the backup on.

Both switches apply to that one call and are never written to diffoniq.ini, so a host cannot leave your installation locked or unprotected; setting the option in the dialog yourself takes precedence. The title bar always names the frozen side, for example [Read-only: left]. Full description: Command Line Arguments; the permanent setting is Create .BAK backup when saving in the File Comparison Options dialog.

Why Diffoniq behaves well as a host's viewer

It stays running until you close the comparison window. Hosts that hand over temporary files rely on this, because they clean up as soon as the viewer returns.
Every call gets its own window and its own process, so stepping through several files, or opening a whole directory comparison, works as expected.
Esc closes a comparison that was started with two paths and hands control back to the host. If you opened a file out of a folder comparison, Esc still takes you back to that listing instead. While a folder comparison is still checking file contents in the background, the first Esc stops that check — the pairs it did not reach stay unverified in the tally and in a report — and a second Esc then closes the comparison.

What Diffoniq does not do here

No merge tool. Diffoniq fills the diff viewer slot only. Do not configure it as the merge tool of a version control client; it cannot write a merge result.
No display names. The title bar shows the path it was given, so with temporary files it shows the temporary path rather than a friendly revision name.
No result exit code. In the graphical mode Diffoniq always exits with 0, whether the sides matched or not. For scripted comparisons use the /sync command line mode, which does define exit codes.
The right-click menu in a folder comparison is Explorer's. Its entries — delete, rename, cut — belong to Windows, and read-only mode does not disable them. Diffoniq's own Synchronize is disabled in read-only mode. The protection is aimed at temporary copies, not at the real folder tree, where Windows asks its own questions and the Recycle Bin catches mistakes.

↑ Usage