Copy a file to a folder.
Create a backup folder if needed, then copy a file into it while preserving its modification time and permission bits.
mkdir -p backup
cp -p -- notes.txt backup/notes.txt
printf 'Copied notes.txt\n'Expected output EXAMPLE
Copied notes.txt
Details
Run in Bash on GNU/Linux. Uses the standard tools supplied with Ubuntu; no elevated permissions are required.
This replaces backup/notes.txt if it already exists. Use cp -i to ask before replacing a file in an interactive shell.
Tested on Ubuntu 24.04.5 LTS · · GNU bash, version 5.2.21(1)-release (x86_64-pc-linux-gnu) · bash 5.2.21-2ubuntu4; coreutils 9.4-3ubuntu6.3
Test inputs, results and environment
The exact published code ran in a dedicated Linux test container with prepared inputs. Unprivileged snippet process, external networking disabled, read-only root filesystem, and a fresh temporary working directory. Fixtures and output records are isolated from the application database. Testing covers this example and its stated checks, not every input, operating system, or runtime version. The Linux container shares its host's kernel; this is not a native Windows test.
- Architecture / host kernel
- x86_64 / 6.18.54.1-microsoft-standard-WSL2
- Snippet identity / locale
- uid=65534, gid=65534 (unprivileged) / C.UTF-8
- Interpreter invocation
bash -euo pipefail -c <published code>- Container image ID
sha256:32dc2d998158b6554c99b73b533f423696a0f3e31e8cbea9db10b5eee9a2fadd- Code SHA-256
393f0d8f3f9f0f396725325b317c9c8c015a664aa3aadc3221f61fd535b412da- Dependencies
- bash 5.2.21-2ubuntu4; coreutils 9.4-3ubuntu6.3
Test input setup
These are the prepared inputs used by the test harness. See Details above for the prerequisites and how to run this example.
printf 'keep this\n' > notes.txt; chmod 640 notes.txt; touch -t 202001020304 notes.txt
Observed standard output
Copied notes.txt
Exit code: 0. Standard error: empty. Validation: Exact stdout comparison. System-dependent values above are one recorded run.
Additional assertions that passed
Checks recorded by the test harness. Where Python assertions are shown, browser cases use Playwright and simulator cases may inspect pin transitions: result.stdout is captured output, work is the temporary directory, and Path is pathlib.Path. The harness also imports json and csv.
assert Path('backup/notes.txt').read_bytes() == Path('notes.txt').read_bytes()
assert Path('backup/notes.txt').stat().st_mtime_ns == Path('notes.txt').stat().st_mtime_ns
assert Path('backup/notes.txt').stat().st_mode == Path('notes.txt').stat().st_mode