Substitute values into a multiline template.

Bash Scripts: An unquoted heredoc delimiter enables parameter expansion in the template.

Bash snippet.sh
set -euo pipefail
name=Ada
cat <<TEXT
Hello $name
Ready.
TEXT

Expected output EXAMPLE

Hello Ada
Ready.

Details

Requires Bash 4 or later. Save as snippet.sh and run bash snippet.sh in an empty working directory. An unquoted heredoc delimiter enables parameter expansion in the template.

✓ 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
ec47492780f22ec51e08beb6e3a0b52efbf3ea0a6c87b0c9ebb3d7b7e3f88ba8
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

Hello Ada
Ready.

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