bash-scriptslisted

# Bash Scripts Practice ## CRITICAL: Bash Script Safety (ABSOLUTE) **You MUST ALWAYS start scripts with:** ```bash #!/usr/bin/env bash set -euo pipefail ``` - `set -e` - Exit immediately if any command fails - `set -u` - Exit if undefined variable is used - `set -o pipefail` - Catch failures in pipes **EXCEPTION:** Only use `set +e` temporarily for commands you EXPECT to fail, then re-enable. --- ## CRITICAL: Test Every Bash Function (ABSOLUTE) **You MUST NEVER add bash functions without bats tests.** Every public function needs a `@test` annotation in bats: ```bash # test/validator.bats @test "validate_config accepts valid JSON" { run validate_config valid.json [ "$status" -eq 0 ] } @test "validate_config rejects invalid JSON" { run validate_config invalid.json [ "$status" -eq 1 ] [[ "$output" =~ "Invalid JSON" ]] } ``` --- ## CRITICAL: Parameter Validation (ABSOLUTE) Validate in every script: - Required parameters exist - Parameter count is correct - File paths exist (if expected) - Enums match expected values ```bash if [ $# -lt 1 ]; then echo "Error: Missing required parameter" >&2 echo "Usage: $0 <config_file>" >&2 exit 1 fi ``` --- ## CRITICAL: Idempotency (ABSOLUTE) **Scripts MUST be safe to run multiple times.** ```bash # WRONG: mkdir output/ # Fails on second run rm config.old # Fails if file doesn't exist # CORRECT: mkdir -p output/ rm -f config.old ``` --- ## Script Structure Pattern ```bash #!/usr/bin/env bash set -e