diff --git a/.gitignore b/.gitignore
index 231a22e..9959f8f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,7 @@
 # Binaries for programs and plugins
 main
-fdup*
+fdup
+fdup-*
 *.exe
 *.exe~
 *.so
diff --git a/fdup.v b/fdup.v
new file mode 100644
index 0000000..6195baa
--- /dev/null
+++ b/fdup.v
@@ -0,0 +1,183 @@
+// fdup - file duplicates finder
+// Copyright (C) 2025 Ge <ge@phreepunk.network>
+//
+// This program is free software: you can redistribute it and/or modify it
+// under the terms of the GNU General Public License as published by the
+// Free Software Foundation, either version 3 of the License, or (at your
+// option) any later version.
+//
+// This program is distributed in the hope that it will be useful, but
+// WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+// or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+// for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this program. If not, see <https://www.gnu.org/licenses/>.
+
+module main
+
+import os
+import cli
+import arrays
+import maps
+import crypto.blake3
+import crypto.sha1
+import crypto.sha256
+import crypto.md5
+import runtime
+import term
+import time
+
+fn main() {
+	mut app := cli.Command{
+		name:        'fdup'
+		description: 'File duplicates finder'
+		version:     '0.1.0'
+		usage:       '[path...]'
+		execute:     find
+		defaults:    struct {
+			man: false
+		}
+		flags:       [
+			cli.Flag{
+				flag:          .string
+				name:          'hash'
+				description:   'Set hashing algorythm: blake3, sha1, sha256, md5 [default: md5]'
+				default_value: ['md5']
+			},
+			cli.Flag{
+				flag:          .int
+				name:          'threads'
+				description:   'Number of threads used for calculating hash sums [default: number of CPU cores]'
+				default_value: [runtime.nr_cpus().str()]
+			},
+			cli.Flag{
+				flag:        .bool
+				name:        'brief'
+				description: 'Brief output, print plain easy to parse hashes and filenames only'
+			},
+		]
+	}
+	app.setup()
+	app.parse(os.args)
+}
+
+fn find(cmd cli.Command) ! {
+	hash_algo := HashAlgo.from_string(cmd.flags.get_string('hash')!) or { HashAlgo.md5 }
+	nr_threads := cmd.flags.get_int('threads')!
+	brief := cmd.flags.get_bool('brief')!
+	mut search_paths := ['.']
+	if cmd.args.len > 0 {
+		search_paths = cmd.args.clone()
+	}
+	// collect full list of files absolute paths
+	mut file_paths := &[]string{}
+	for search_path in search_paths {
+		norm_path := os.norm_path(os.abs_path(os.expand_tilde_to_home(search_path)))
+		os.walk(norm_path, fn [mut file_paths] (file string) {
+			file_paths << file
+		})
+	}
+	eprintln('found ${file_paths.len} files, processing...')
+	// split the files list into approximately equal parts by the number of threads
+	mut parts := [][]string{}
+	if nr_threads == 1 {
+		parts = [*file_paths]
+	} else {
+		parts = arrays.chunk(*file_paths, file_paths.len / nr_threads)
+		mut idx := 0
+		for parts.len != nr_threads {
+			parts[idx] = arrays.append(parts[0], parts.last())
+			parts.delete_last()
+			idx++
+			if idx >= parts.len {
+				idx = 0
+			}
+		}
+	}
+	// calculate hashsums in parallel
+	mut threads := []thread map[string]string{}
+	for i := 0; i < nr_threads; i++ {
+		threads << spawn calculate_hashsums(parts[i], hash_algo)
+	}
+	calculated := threads.wait()
+	mut sums := map[string]string{}
+	for s in calculated {
+		maps.merge_in_place(mut sums, s)
+	}
+	// find and pretty-print duplicates
+	dups := find_duplicates(sums)
+	if dups.len == 0 {
+		eprintln(term.bold('no duplicates found'))
+		exit(0)
+	}
+	for hash, files in dups {
+		if brief {
+			for file in files {
+				println(hash + ':' + file)
+			}
+		} else {
+			println(term.bold(hash))
+			for file in files {
+				stat := os.stat(file)!
+				println('\t${time.unix(stat.mtime)}\t${file}')
+			}
+		}
+	}
+	exit(2)
+}
+
+fn find_duplicates(files map[string]string) map[string][]string {
+	mut dups := map[string][]string{}
+	for _, hash in files {
+		if hash !in dups {
+			for f, h in files {
+				if h == hash {
+					dups[hash] << f
+				}
+			}
+		}
+	}
+	for h, f in dups {
+		if f.len == 1 {
+			dups.delete(h)
+		}
+	}
+	return dups
+}
+
+enum HashAlgo {
+	blake3
+	sha1
+	sha256
+	md5
+}
+
+fn hashsum(file string, algo HashAlgo) string {
+	file_bytes := os.read_bytes(file) or { []u8{len: 1} }
+	defer {
+		unsafe { file_bytes.free() }
+	}
+	match algo {
+		.blake3 {
+			return blake3.sum256(file_bytes).hex()
+		}
+		.sha1 {
+			return sha1.sum(file_bytes).hex()
+		}
+		.sha256 {
+			return sha256.sum(file_bytes).hex()
+		}
+		.md5 {
+			return md5.sum(file_bytes).hex()
+		}
+	}
+}
+
+fn calculate_hashsums(files []string, hash HashAlgo) map[string]string {
+	mut sums := map[string]string{}
+	for file in files {
+		sums[file] = hashsum(file, hash)
+	}
+	return sums
+}