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Reading Logs 2: Getting Answers from Logs with Pipes, Redirection, grep, awk, sed, sort and uniq

The way to get answers out of logs is to chain small tools with pipes: awk extracts a field, grep filters, sort orders, uniq -c counts. After the basics of stdin/stdout/stderr and redirection, we find the top IPs, 5xx per minute, the slowest requests and a request ID's trail in the application log on Bookstore's real Nginx access log, and show the uniq, regex and locale pitfalls.