Function getdents

pub unsafe fn getdents(fd: i32, dir_buf: &mut [u8]) -> Result<isize, i32> 

Available on crate feature dep_nc only.

Get directory entries.

Examples

use std::mem::offset_of;

const BUF_SIZE: usize = 1 * 1024;

let path = "/etc";
let ret = unsafe { nc::openat(nc::AT_FDCWD, path, nc::O_DIRECTORY, 0) };
assert!(ret.is_ok());
let fd = ret.unwrap();
let mut buf = [0; BUF_SIZE];

loop {
    let ret = unsafe { nc::getdents(fd, &mut buf) };
    assert!(ret.is_ok());
    let nread = ret.unwrap() as usize;
    if nread == 0 {
        break;
    }

    let buf_ptr: *const u8 = buf.as_ptr();
    let mut bpos: usize = 0;

    println!("--------------- nread={nread} ---------------");
    println!("inode#    file type  d_reclen  d_off   d_name");
    while bpos < nread {
        let d = buf_ptr.wrapping_add(bpos) as *mut nc::linux_dirent_t;
        let d_ref: &nc::linux_dirent_t = unsafe { &(*d) };
        let d_type = match d_ref.d_type() {
            nc::DT_REG => "regular",
            nc::DT_DIR => "directory",
            nc::DT_FIFO => "FIFO",
            nc::DT_SOCK => "socket",
            nc::DT_LNK => "symlink",
            nc::DT_BLK => "block-dev",
            nc::DT_CHR => "char-dev",
            _ => "unknown",
        };

        if let Ok(name) = std::str::from_utf8(d_ref.name()) {
            println!(
                "{: >8}  {:<10} {: >4} {: >12}  {}",
                d_ref.d_ino, d_type, d_ref.d_reclen, d_ref.d_off as u32, name
            );
        } else {
            eprintln!("Invalid name: {:?}", d_ref.name());
        }

        bpos += d_ref.d_reclen as usize;
    }
    break;
}
let offset = offset_of!(nc::linux_dirent_t, d_name);
println!("offset of d_name is: {}", offset);
println!(
    "offset of d_reclen is: {}",
    offset_of!(nc::linux_dirent_t, d_reclen)
);

let ret = unsafe { nc::close(fd) };
assert!(ret.is_ok());