Parse latitude longitude information from Exif tag for files in a directory (initial boilerplate from you.com, improved with kamadak-exif sample code)

parse_latlon.rs

use std::env;
use std::fs;
use std::fs::File;
use std::io::BufReader;
use std::path::PathBuf;

use exif::{In, Reader, Tag};

fn main() {
    let args: Vec<String> = env::args().collect();

    if args.len() < 2 {
        println!("Usage: {} <photo_directory>", args[0]);
        return;
    }

    let photo_dir = &args[1];
    println!("Photo directory {}", photo_dir);

    match fs::read_dir(PathBuf::from(photo_dir)) {
        Ok(paths) => {
            for path in paths {
                let file_path = path.unwrap().path();
                println!("path {}", file_path.display());

                let file_name = file_path.file_name().unwrap().to_str().unwrap().to_lowercase();

                if file_name.ends_with(".jpg") || file_name.ends_with(".jpeg") || file_name.ends_with(".mp4") || file_name.ends_with("mov") {
                    let file = File::open(&file_path).unwrap();
                    let exif = Reader::new().read_from_container(
                        &mut BufReader::new(file)).unwrap();

                    // To obtain a string representation, `Value::display_as`
                    // or `Field::display_value` can be used.  To display a value with its
                    // unit, call `with_unit` on the return value of `Field::display_value`.
                    let tag_list = [Tag::ExifVersion,
                    Tag::PixelXDimension,
                    Tag::XResolution,
                    Tag::ImageDescription,
                    Tag::DateTime];
                    for tag in tag_list {
                        if let Some(field) = exif.get_field(tag, In::PRIMARY) {
                            println!("{}: {}",
                                     field.tag, field.display_value().with_unit(&exif));
                        }
                    }

                    if let Some(latitude) = exif.get_field(Tag::GPSLatitude, In::PRIMARY) {
                        println!("Latitude: {}", latitude.display_value().with_unit(&exif));
                    }
                    if let Some(longitude) = exif.get_field(Tag::GPSLongitude, In::PRIMARY) {
                        println!("Longitude: {}", longitude.display_value().with_unit(&exif));
                    }

                    println!("File name: {}", file_name);
                }
            }
        }

        Err(e) => {
            println!("Error: {:?}", e);
        }
    }
}