Read the length of an ASCII string.

Bash Scripts: Read the length of an ASCII string with a small standalone Bash program.

Bash snippet.sh
#!/usr/bin/env bash
set -euo pipefail

message=Learn
printf '%s\n' "${#message}"

Expected output EXAMPLE

5

Details

Requires Bash 4 or later. Save as snippet.sh and run bash snippet.sh in an empty working directory.

✓ Verified

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. Snippet process uid 65534 with a read-only root filesystem and temporary working files. Networking disabled. 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 process) / C.UTF-8
Interpreter invocation
bash -euo pipefail -c <published code>
Container image ID
sha256:ec91410a8f6ec3e985830b5e3a0560306d36f8c1c5ccd91a6699abe707123fa3
Code SHA-256
2498bc112897b4fb0935ac69c46a80d560773164cf2bbaa0a3d2f88477a95ef5
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.

# No input files required.

Observed standard output

5

Exit code: 0. Standard error: empty. Validation: Exact stdout comparison. System-dependent values above are one recorded run.