Function test_readlink

crates/test-programs/src/bin/p1_readlink.rs:6–35

(dir_fd: wasip1::Fd)

use test_programs::preview1::{create_file, open_scratch_directory};

unsafe fn test_readlink(dir_fd: wasip1::Fd) {
    // Create a file in the scratch directory.
    create_file(dir_fd, "target");

    // Create a symlink
    wasip1::path_symlink("target", dir_fd, "symlink").expect("creating a symlink");

    // Read link into the buffer
    let buf = &mut [0u8; 10];
    let bufused = wasip1::path_readlink(dir_fd, "symlink", buf.as_mut_ptr(), buf.len())
        .expect("readlink should succeed");
    assert_eq!(bufused, 6, "should use 6 bytes of the buffer");
    assert_eq!(&buf[..6], b"target", "buffer should contain 'target'");
    assert_eq!(
        &buf[6..],
        &[0u8; 4],
        "the remaining bytes should be untouched"
    );

    // Read link into smaller buffer than the actual link's length
    let buf = &mut [0u8; 4];
    let bufused = wasip1::path_readlink(dir_fd, "symlink", buf.as_mut_ptr(), buf.len())
        .expect("readlink with too-small buffer should silently truncate");
    assert_eq!(bufused, 4);
    assert_eq!(buf, b"targ");

    // Clean up.
    wasip1::path_unlink_file(dir_fd, "target").expect("removing a file");
    wasip1::path_unlink_file(dir_fd, "symlink").expect("removing a file");
}

unsafe fn test_incremental_readlink(dir_fd: wasip1::Fd) {
    let filename = "Действие";