Premium: Bash Script Practice

Now combine everything: variables, functions, loops, and conditionals to build a real-world automation script.

Create multiple log files with a loop. Each iteration writes a new file.

Use glob patterns to process all files at once.

Combine pipes and commands to get meaningful statistics from your data.

You're managing 10 microservices. Each generates a deploy log. Build a script that:

1. Creates a backup directory with all current logs.
2. Filters for error lines.
3. Counts total errors across all services.

printf '%s\n' 'INFO deploy started' 'ERROR health check failed' > web.log
printf '%s\n' 'INFO deploy complete' > api.log

function check_deploys {
  mkdir -p backup_deploys
  for service in web api cache queue worker db; do
    if [ -f "$service.log" ]; then
      cp "$service.log" backup_deploys/
      error_count=$(grep -c 'ERROR' "backup_deploys/$service.log")
      echo "Service $service has $error_count errors"
    fi
  done
}

check_deploys

1. Iterate with for var in list; do ...; done.
2. Check conditions with if [ test ]; then ...; fi.
3. Capture output with $(command).
4. Process files with cat *.ext | grep | wc -l.
5. Organize with functions that bundle related tasks.