Configuration

fd has no configuration file. Every option is a CLI flag or an environment variable. This page is the canonical reference for both, plus the ignore-file locations fd reads.

The Config struct

Config lives in src/config.rs. Every field is set once by construct_config (src/main.rs) and read by the walker, filters, exec, and output subsystems. The fields are grouped here roughly by topic.

Search behaviour

Field	CLI flag	Default	Notes
case_sensitive	-s/-i/(smart)	smart	Smart case via pattern_has_uppercase_char.
full_path_base	-p, --full-path	None	When Some(cwd), patterns match against the absolute path.
max_depth	-d, --max-depth, --exact-depth	None	--exact-depth N sets both max_depth and min_depth to N.
min_depth	--min-depth, --mindepth	None	--mindepth is a hidden alias for --min-depth (10.3.0).
prune	--prune	false	When matching, do not descend into the matched directory.
threads	-j, --threads	min(available_parallelism, 64)	See default_num_threads in src/cli.rs.
quiet	-q, --quiet	false	Print nothing; exit 0 iff at least one match.
max_buffer_time	--max-buffer-time	None (uses 100 ms default in walk.rs)	Override the buffer-then-stream switchover.
max_results	--max-results, -1/--max-one-result	None	Stops the walker once reached.

Ignore behaviour

Field	CLI flag	Default	Notes
ignore_hidden	-H/--hidden, -u/--unrestricted	true	Skip dotfiles.
read_fdignore	-I/--no-ignore, -u	true	.ignore and .fdignore files.
read_vcsignore	-I, --no-ignore-vcs, -u	true	.gitignore, global gitignore, .git/info/exclude.
require_git_to_read_vcsignore	--no-require-git/--require-git	true	Only honour git rules inside a git repo.
read_parent_ignore	--no-ignore-parent/--ignore-parent	true	Walk up to ancestor directories looking for ignore files.
read_global_ignore	--no-global-ignore-file	true	Read ${etcetera::config_dir()}/fd/ignore.
exclude_patterns	-E, --exclude	empty	Each pattern is prefixed with ! and fed to OverrideBuilder.
ignore_files	--ignore-file	empty	Custom ignore files.
ignore_contain	--ignore-contain	empty	Skip directories that contain a marker file.
follow_links	-L, --follow	false	Symlink-following walker.
one_file_system	--one-file-system, --mount	false	Refuse to cross filesystem boundaries.

Filter constraints

Field	CLI flag	Default	Source
file_types	-t, --type	None	src/filetypes.rs
extensions	-e, --extension	None	Compiled to a RegexSet.
size_constraints	-S, --size	empty	Multiple may be specified; AND-merged.
time_constraints	--changed-within, --changed-before	empty	Both may apply.
owner_constraint	-o, --owner (Unix only)	None	user:group, with ! for negation.

Output

Field	CLI flag	Default	Notes
null_separator	-0, --print0	false	Use \0 between results and after exec output blocks.
ls_colors	-c auto/always/never	Auto (terminal-aware)	Falls back to bundled DEFAULT_LS_COLORS when env is unset.
hyperlink	--hyperlink[=auto/always/never]	Auto (follows colors)	OSC 8 hyperlinks.
format	--format	None	Output template (shares engine with --exec).
path_separator	--path-separator	None	On Windows must be one byte.
actual_path_separator	derived	path_separator.unwrap_or(MAIN_SEPARATOR)	Used by the trailing-slash printer.
strip_cwd_prefix	--strip-cwd-prefix [auto/always/never]	Auto	Strip ./ from results when there's no positional search path and no exec/-0.

Exec

Field	CLI flag	Default	Notes
command	-x, -X, -l	None	Arc<CommandSet> (see src/exec/).
batch_size	--batch-size	0 (no limit)	Used by CommandBuilder to flush a batch.
interactive_terminal	derived	is_terminal(stdout)	Used by output.rs for raw-bytes printing on Unix.
show_filesystem_errors	--show-errors	false	Emit traversal errors to stderr.

Environment variables

Variable	Effect
LS_COLORS	Used by LsColors::from_env to pick file colors. If unset, fd falls back to its bundled DEFAULT_LS_COLORS (see src/main.rs).
NO_COLOR	Disables coloured output unless --color=always. Implemented in construct_config.
TERM	Used on Windows to decide whether to attempt enable_ansi_support().
MSYSTEM	If set on Windows, fd sets the default path separator to / (default_path_separator in src/filesystem.rs).
XDG_CONFIG_HOME (and platform equivalents)	Resolved by etcetera::choose_base_strategy() to find the global ignore file.
CARGO_BIN_EXE_fd	Set by Cargo for integration tests; consumed by tests/testenv/mod.rs to find the just-built binary.

There is no FD_CONFIG or similar — fd intentionally has no project-level config file beyond the ignore files.

Ignore-file paths

File	Location	Notes
Per-project	.gitignore, .ignore, .fdignore	At any directory level; closer-to-the-file rules win.
Per-user	${etcetera::config_dir()}/fd/ignore	On Linux/macOS typically ~/.config/fd/ignore; on Windows %APPDATA%\fd\ignore.
Per-repo git	.git/info/exclude	Honoured via WalkBuilder::git_exclude.
Global git	~/.config/git/ignore (or core.excludesfile)	Honoured via WalkBuilder::git_global.

The exact rules come from the ignore crate. fd's only choice is whether to enable each source.

Locale and encoding

• fd does no locale-dependent matching. Smart case uses char::is_uppercase, which is Unicode-aware.
• Filenames are processed as bytes on Unix (osstr_to_bytes returns a borrowed slice via OsStrExt::as_bytes) and as lossy UTF-8 on Windows. Patterns compile against regex::bytes::Regex.
• Output path printing on Unix prefers raw-byte writes when stdout is non-interactive and no path separator rewrite is requested, preserving non-UTF-8 names.

Exit code reference

See exit-codes.