That looks oddly familiar

README.md

In which Rust and perceptual hashing come together.

Cargo.toml

[package]
name = "phash"
version = "0.1.0"
authors = ["Jan Stępień"]

[dependencies]
libc = "0.2.36"
rayon = "0.9.0"

main.rs

extern crate libc;
extern crate rayon;

use std::env;
use std::ffi::CString;
use libc::{uint64_t, c_char, c_int};
use rayon::prelude::*;

#[link(name = "pHash")]
extern {
  fn ph_dct_imagehash(
    file: *const c_char,
    hash: *mut uint64_t
  ) -> c_int;
}

fn imagehash(file: &str) -> Option<u64> {
  let mut hash: u64 = 0;
  let cstr = CString::new(file).unwrap();
  unsafe {
    let ptr = cstr.as_ptr();
    match ph_dct_imagehash(ptr, &mut hash) {
      0 => Some(hash),
      _ => None,
    }
  }
}

fn main() {
  let files: Vec<_> = env::args().skip(1).collect();
  files.par_iter().for_each(|file| {
    match imagehash(&file) {
      Some(hash) => println!("{:016x} {}", hash, file),
      None => eprintln!("Failed to hash {}", file),
    }
  })
}