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Using bfs

bfs has the same command line syntax as find, and almost any find command that works with a major find implementation will also work with bfs. When invoked with no arguments, bfs will list everything under the current directory recursively, breadth-first:

$ bfs
.
./LICENSE
./Makefile
./README.md
./completions
./docs
./src
./tests
./completions/bfs.bash
./completions/bfs.zsh
./docs/BUILDING.md
./docs/CHANGELOG.md
./docs/CONTRIBUTING.md
./docs/USAGE.md
./docs/bfs.1
...

Paths

Arguments that don't begin with - are treated as paths to search. If one or more paths are specified, they are used instead of the current directory:

$ bfs /usr/bin /usr/lib
/usr/bin
/usr/lib
/usr/bin/bfs
...
/usr/lib/libc.so
...

Expressions

Arguments that start with - form an expression which bfs evaluates to filter the matched files, and to do things with the files that match. The most common expression is probably -name, which matches filenames against a glob pattern:

$ bfs -name '*.md'
./README.md
./docs/BUILDING.md
./docs/CHANGELOG.md
./docs/CONTRIBUTING.md
./docs/USAGE.md

Operators

When you put multiple expressions next to each other, both of them must match:

$ bfs -name '*.md' -name '*ING*'
./docs/BUILDING.md
./docs/CONTRIBUTING.md

This works because the expressions are implicitly combined with logical and. You could be explicit by writing

$ bfs -name '*.md' -and -name '*ING'`

There are other operators like -or:

$ bfs -name '*.md' -or -name 'bfs.*'
./README.md
./completions/bfs.bash
./completions/bfs.fish
./completions/bfs.zsh
./docs/BUILDING.md
./docs/CHANGELOG.md
./docs/CONTRIBUTING.md
./docs/USAGE.md
./docs/bfs.1

and -not:

$ bfs -name '*.md' -and -not -name '*ING*'
./README.md
./docs/CHANGELOG.md
./docs/USAGE.md

Actions

Every bfs expression returns either true or false. For expressions like -name, that's all they do. But some expressions, called actions, have other side effects.

If no actions are included in the expression, bfs adds the -print action automatically, which is why the above examples actually print any output. The default -print is supressed if any actions are given explicitly. Available actions include printing with alternate formats (-ls, -printf, etc.), executing commands (-exec, -execdir, etc.), deleting files (-delete), and stopping the search (-quit, -exit).

Extensions

bfs implements a few extensions not found in other find implementations.

-exclude

The -exclude operator skips an entire subtree whenever an expression matches. For example, -exclude -name .git will exclude any files or directories named .git from the search results. -exclude is easier to use than the standard -prune action; compare

bfs -name config -exclude -name .git

to the equivalent

find ! \( -name .git -prune \) -name config

Unlike -prune, -exclude even works in combination with -depth/-delete.

-limit

The -limit N action makes bfs quit once it gets evaluated N times. Placing it after an action like -print limits the number of results that get printed, for example:

$ bfs -s -type f -name '*.txt'
./1.txt
./2.txt
./3.txt
./4.txt
$ bfs -s -type f -name '*.txt' -print -limit 2
./1.txt
./2.txt

This is similar to

$ bfs -s -type f -name '*.txt' | head -n2

but more powerful because you can apply separate limits to different expressions:

$ bfs \( -name '*.txt' -print -limit 3 -o -name '*.log' -print -limit 4 \) -limit 5
[At most 3 .txt files, at most 4 .log files, and at most 5 in total]

and more efficient because it will quit immediately. When piping to head, bfs will only quit after it tries to output too many results.

-hidden/-nohidden

-hidden matches "hidden" files (dotfiles). bfs -hidden is effectively shorthand for

find \( -name '.*' -not -name . -not -name .. \)

-nohidden is equivalent to -exclude -hidden.

-unique

This option ensures that bfs only visits each file once, even if it's reachable through multiple hard or symbolic links. It's particularly useful when following symbolic links (-L).

-color/-nocolor

When printing to a terminal, bfs automatically colors paths like GNU ls, according to the LS_COLORS environment variable. The -color and -nocolor options override the automatic behavior, which may be handy when you want to preserve colors through a pipe:

bfs -color | less -R

If the NO_COLOR environment variable is set, colors will be disabled by default.