Commands by MacMladen (1)

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Benchmark SQL Query
Benchmark a SQL query against MySQL Server. The example runs the query 10 times, and you get the average runtime in the output. To ensure that the query does not get cached, use `RESET QUERY CACHE;` on top in the query file.

Adding Prefix to File name
Good old bracket expansion :-) For large numbers of files, "rename" will spare you the for-loop, or the find/exec...

Recursive replace of directory and file names in the current directory.
This should work anywhere perl and grep is available. :P

Convert CSV to JSON
Replace 'csv_file.csv' with your filename.

Upgrade all perl modules via CPAN

Calculate days on which Friday the 13th occurs (inspired from the work of the user justsomeguy)
Friday is the 5th day of the week, monday is the 1st. Output may be affected by locale.

Filter IPs out of files

display systemd log entries for sshd using "no-pager" (a bit like in pre-systemd: grep sshd /var/log/messages)
In pre-systemd systems, something like: "# grep sshd /var/log/messages" would display log events in /var/log/messages containing "sshd". # journalctl -u sshd --no-pager The above command displays similar results for systemd systems. (Note that this needs to be run with root permissions to access the log data.)

Add temporary <1m entries to old cron
Old cron doesn't allow periods

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

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