ff diff

Show a patch: the open change by default, a set's total patch with -r, or the difference between two revisions with --from and --to. With no paths, include the whole eligible change, including newly created untracked files.

Usage

Usage: ff diff [OPTIONS] [path]...

Examples

ff diff                         # Whole open change
ff diff src/                    # Changes under src/
ff diff -r HEAD                 # What HEAD did
ff diff -r 'trunk..@'           # The branch plus open work, against trunk
ff diff --from main             # main to the open change
ff diff --from v1 --to v2       # Two points
ff diff --stat                  # File counts instead of a patch
ff diff --name-only             # Changed paths and change types
ff diff -U0 -r HEAD             # No context lines
ff diff --json                  # Hunks and lines as fields
ff diff > fix.patch             # Save a patch for git apply
ff op diff '@^' @               # Compare two recorded file trees

Options

Arguments:
  [path]...
          Files or directories to limit the patch to; all of them when omitted

Options:
  -r, --revisions <revset>
          Revisions whose total patch to show, as a revset; the open change without it

      --from <rev>
          Older end of a two-point patch; `@^`, HEAD, when only --to is given

      --to <rev>
          Newer end of a two-point patch; `@`, the open change, when omitted

      --json
          Emit machine-readable JSON

      --stat
          Print the diffstat instead of the patch

      --fetch
          Fetch now on commands that support fetching, regardless of cadence

      --name-only
          Print one path per line with its change type instead of the patch

      --no-fetch
          Skip the fetch: read the tracking refs as they stand

  -U, --unified <n>
          Context lines around each change; 3 when omitted

      --session <name>
          Session name for this invocation

      --fields <list>
          Keep only these dotted paths of the JSON data, comma-separated

  -C, --cwd <dir>
          Run as if fufu had been started in <dir>

  -h, --help
          Print help (see a summary with '-h')

Choosing what to compare

-r selects a revision set and shows its combined patch. -r HEAD shows the latest commit; -r 'trunk..@' includes the branch's commits and open work beyond trunk. The set must be connected, with one root and one head. Use ff log -r <revset> to inspect its members if it is refused with usage/revset-not-a-range. The open change alone, -r @, is accepted.

The patch runs from the root's parent to the head. A merge root uses the auto-merge of its parents, falling back to the first parent when that auto-merge conflicts or has no common ancestor. A fallback is reported on stderr. A root commit with no parents uses the empty tree.

--from and --to compare two revisions, like git diff a b. --to defaults to @, the open change; when only --to is supplied, --from defaults to HEAD. Thus --from main compares main with the branch's current files, including open work. Use these flags together or use -r; combining the two forms is refused with usage/bad-flags.

Paths and output

Paths select files or directory prefixes, without globs. Snapshot exclusions apply, including ignored untracked files and content above fufu.maxFileSize. A positional that names no path on disk or in HEAD is refused with usage/no-such-path, so a revision such as main..HEAD in the path slot is an error rather than an empty patch; revisions go behind -r, --from, and --to. A path that exists but has no changes prints an empty patch and exits 0.

Text output is a unified diff suitable for git apply. Use --stat for per-file change counts or --name-only for paths and change types. These two flags are mutually exclusive. -U <n> sets the number of context lines, 3 by default; it has no effect when no patch is printed.

JSON output

--stat omits each file's hunks. --name-only keeps path, from, kind, and binary per file and omits change counts. With -r, against identifies the comparison base: parent, auto-merge, or first-parent. Bare diff and two-point comparisons omit against. See JSON output and scripting.