Copy A Directory Recursively In Rust Without std::fs::copy

May 2024

See the notes below

```cargo
[dependencies]
walkdir = "2.5.0"
```

use std::fs;
use std::path::PathBuf;
use walkdir::WalkDir;

fn main() {
  let source = PathBuf::from("target_source");
  let dest = PathBuf::from("target_dest");
  match copy_dir(&source, &dest) {
    Ok(_) => { println!("copied the directory"); }
    Err(e) =>  { println!("{:?}", e); }
  }
}

pub fn copy_dir(source_dir: &PathBuf, dest_dir: &PathBuf) -> Result<(), std::io::Error> {
  for entry in WalkDir::new(source_dir) {
    let source_path = entry?.into_path();
    let dest_path = dest_dir.join(source_path.strip_prefix(source_dir).unwrap());
    if source_path.is_dir() {
      fs::create_dir_all(dest_path)?;
    }
    else {
      let data = std::fs::read(source_path)?;
      std::fs::write(dest_path, &data)?;
    }
  }
  Ok(())
}

Output:

error: unknown start of token: `
 --> _active_nvim_run:1:1
  |
1 | ```cargo
  | ^^^
  |
  = note: character appears 2 more times
help: Unicode character '`' (Grave Accent) looks like ''' (Single Quote), but it is not
  |
1 - ```cargo
1 + '''cargo
  |

error: unknown start of token: `
 --> _active_nvim_run:4:1
  |
4 | ```
  | ^^^
  |
  = note: character appears 2 more times
help: Unicode character '`' (Grave Accent) looks like ''' (Single Quote), but it is not
  |
4 - ```
4 + '''
  |

error: expected one of `!` or `::`, found `[`
 --> _active_nvim_run:2:1
  |
1 | ```cargo
  |         - expected one of `!` or `::`
2 | [dependencies]
  | ^ unexpected token

error: could not compile `_active_nvim_run` (bin "_active_nvim_run") due to 3 previous errors

Notes

There's an issue with notify and std::fs::copy where copying a file triggers an event. That means you can't watch and copy files the way you'd expect because they keep triggeing themselves
This is very naive (e.g. it doesn't deal with links or have substantial error handling)

end of line

References

Notify seems to trigger on std::fs::copy but not std::io::copy or std::fs::{read,write} #259