Encode and decode a file with Base64.
Linux Commands: Use GNU base64 for text transport of bytes and --decode for the reverse operation.
base64 -w 0 data.txt > encoded.txt
cat encoded.txt
printf "\n"
base64 --decode encoded.txt
printf "\n"Expected output EXAMPLE
aGVsbG8= hello
Details
Run in Bash on GNU/Linux in a scratch directory. Tested with the GNU utilities supplied by Ubuntu. Use GNU base64 for text transport of bytes and --decode for the reverse operation.
Base64 is not encryption and does not provide authenticity.
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; sed 4.9-2ubuntu0.24.04.1
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
522cd8f533984075d7a029f3e8ef76f0d81dd7d142f3e1489f2286797b5a385c- Dependencies
- bash 5.2.21-2ubuntu4; coreutils 9.4-3ubuntu6.3; sed 4.9-2ubuntu0.24.04.1
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 'hello' > data.txt
Observed standard output
aGVsbG8= hello
Exit code: 0. Standard error: empty. Validation: Exact stdout comparison. System-dependent values above are one recorded run.