Files
wasmtime/crates/test-programs/wasi-tests/src/bin/readlink.rs
2021-01-27 18:10:38 -08:00

57 lines
1.7 KiB
Rust

use std::{env, process};
use wasi_tests::{assert_errno, create_file, open_scratch_directory};
unsafe fn test_readlink(dir_fd: wasi::Fd) {
// Create a file in the scratch directory.
create_file(dir_fd, "target");
// Create a symlink
wasi::path_symlink("target", dir_fd, "symlink").expect("creating a symlink");
// Read link into the buffer
let buf = &mut [0u8; 10];
let bufused = wasi::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 err = wasi::path_readlink(dir_fd, "symlink", buf.as_mut_ptr(), buf.len())
.err()
.expect("readlink with too-small buffer should fail");
assert_errno!(err.raw_error(), wasi::ERRNO_RANGE);
// Clean up.
wasi::path_unlink_file(dir_fd, "target").expect("removing a file");
wasi::path_unlink_file(dir_fd, "symlink").expect("removing a file");
}
fn main() {
let mut args = env::args();
let prog = args.next().unwrap();
let arg = if let Some(arg) = args.next() {
arg
} else {
eprintln!("usage: {} <scratch directory>", prog);
process::exit(1);
};
// Open scratch directory
let dir_fd = match open_scratch_directory(&arg) {
Ok(dir_fd) => dir_fd,
Err(err) => {
eprintln!("{}", err);
process::exit(1)
}
};
// Run the tests.
unsafe { test_readlink(dir_fd) }
}