FsUtils.cr

File system utilities (like grep and find) as Crystal helper classes for use without running shell commands.

AI Use

See DISCLOSURE for how I used AI for this project.

Installation

1. Add the dependency to your shard.yml:

   dependencies:
      fsutils:
        github: nogginly/fsutils.cr
   

2. Run shards install

Usage

Both helpers stream: the block sees each result as it is found, and run returns a report saying what the walk cost and why it stopped. That last part matters — an empty tail means nothing unless you can tell "no more matches" from "I gave up".

Find

require "fsutils"

report = FsUtils::Find.new("src", name: ["*.cr"]).run do |m|
  puts "#{m.path} (#{m.size} bytes)"
end

report.matches     # => 12
report.stop_reason # => Completed
report.truncated?  # => false

Grep

require "fsutils"

report = FsUtils::Grep.new("TODO", "src", types: ["cr"]).run do |m|
  puts "#{m.relative_path}:#{m.line_number}:#{m.column}: #{m.line}"
end

report.stop_reason # => MaxMatches, if the budget ran out first

Pass mode: FsUtils::Grep::Mode::Paths to get one result per file instead of one per line — much cheaper when the question is "which files mention this".

Guard rails

Every search is bounded by default, because the intended caller is an AI agent that cannot see a runaway scan and pays for every result it receives. Matches, matches per directory, matches per file, entries scanned, depth and elapsed time all have caps; .git, node_modules and the usual sinkholes are skipped; symlinks are not followed; hidden entries are ignored. All of it is adjustable, and none of it raises — unreadable directories become report.errors, not an exception.

See DESIGN for the reasoning, and samples/ for two small command-line tools built on the helpers:

ops build-debug
./bin/debug/fsu-grep TODO src -t cr
./bin/debug/fsu-find src --name "*.cr" --max-matches 20

Development

See DEVELOPMENT

Contributions, by invitation!

With apologies, at this time contributions are by invitation only and limited to people I know and see often.

These are early days for FsUtils and I am busy with family and work.

At this time I want to work on this at a manageable pace.