Filter lines by literal text.

Linux Commands: Filter lines by literal text using GNU/Linux commands in an empty practice directory.

Bash terminal
printf 'INFO ready\nERROR missing\n' | grep -F 'ERROR'

Expected output EXAMPLE

ERROR missing

Details

Run in Bash on GNU/Linux in a scratch directory. Tested with the GNU utilities supplied by Ubuntu.

Keep in mind

File examples use disposable names in your current directory. Start in an empty practice directory to avoid replacing existing files.

✓ 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. 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
f114ba0feab25e94a75a1fb3e690d7e1fc22715c09e87a1dd7c3c6829f2f757a
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

ERROR missing

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