Read from a dedicated file descriptor.
Bash Scripts: An explicitly opened descriptor keeps the script’s ordinary standard input available.
set -euo pipefail
exec 3< lines.txt
IFS= read -r first <&3
IFS= read -r second <&3
exec 3<&-
printf "%s / %s\n" "$first" "$second"Expected output EXAMPLE
one / two
Details
Requires Bash 4 or later. Save as snippet.sh and run bash snippet.sh in an empty working directory. An explicitly opened descriptor keeps the script’s ordinary standard input available.
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
7f99a456e7a618e4175fce3399818758915b1e89ada52bd1d3263e4b2952db18- 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 'one\ntwo\n' > lines.txt
Observed standard output
one / two
Exit code: 0. Standard error: empty. Validation: Exact stdout comparison. System-dependent values above are one recorded run.