moved low-level code into fat-bits subcrate

fat-dump/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "fat-dump"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+anyhow = "1.0.98"
+fat-bits = { version = "0.1.0", path = "../fat-bits" }

fat-dump/src/main.rs

@@ -0,0 +1,78 @@
+use fat_bits::dir::{DirIter, RegularDirEntry};
+use fat_bits::fat::Fatty as _;
+use fat_bits::{FatFs, SliceLike};
+
+pub fn main() -> anyhow::Result<()> {
+    let args = std::env::args();
+
+    if args.len() != 2 {
+        anyhow::bail!("usage: dump <path>");
+    }
+
+    let file = std::fs::File::open(args.skip(1).next().unwrap())?;
+
+    // let mut buf = [0; 512];
+
+    // file.read_exact(&mut buf)?;
+
+    // let bpb = Bpb::load(&buf)?;
+
+    // println!("{}", bpb);
+
+    let fat_fs = FatFs::load(file)?;
+
+    println!("{}", fat_fs.bpb());
+    println!();
+    println!("{}", fat_fs.fat());
+    println!();
+    println!(
+        "free clusters: {} ({} bytes)",
+        fat_fs.fat().count_free_clusters(),
+        fat_fs.fat().count_free_clusters()
+            * fat_fs.bpb().bytes_per_sector() as usize
+            * fat_fs.bpb().sectors_per_cluster() as usize
+    );
+
+    println!();
+    println!();
+
+    tree(&fat_fs, false);
+
+    Ok(())
+}
+
+fn tree<S: SliceLike>(fat_fs: &FatFs<S>, show_hidden: bool) {
+    fn do_indent(indent: u32) {
+        for _ in 0..indent {
+            print!("    ");
+        }
+    }
+
+    fn tree_impl<S: SliceLike>(
+        fat_fs: &FatFs<S>,
+        iter: impl Iterator<Item = RegularDirEntry>,
+        show_hidden: bool,
+        indent: u32,
+    ) {
+        for dir_entry in iter.filter(|x| show_hidden || !x.is_hidden()) {
+            do_indent(indent);
+
+            println!("{}", dir_entry);
+
+            if dir_entry.is_dot() || dir_entry.is_dotdot() {
+                // do not descent into . and ..
+                continue;
+            }
+
+            if dir_entry.is_dir() {
+                let reader = fat_fs.chain_reader(dir_entry.first_cluster());
+
+                let iter = DirIter::new(reader);
+
+                tree_impl(fat_fs, iter, show_hidden, indent + 1);
+            }
+        }
+    }
+
+    tree_impl(fat_fs, fat_fs.root_dir_iter(), show_hidden, 0);
+}