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Prints a file leaving out all blank lines and comment-only lines
Does not print any line that either: - is empty - contains only spaces or tabs - starts with # - starts with spaces/tabs followed by a #

list files recursively by size

Append stdout and stderr to a file, and print stderr to the screen [bash]
Useful for cron jobs -- all output will be logged but only errors will cause email to be sent. NB the order of "2>&1" and ">> logfile" is important, it doesn't work if you reverse them (everything goes to the logfile, nothing left for tee).

check open ports without netstat or lsof

Set all CPU cores' CPU frequency scaling governor to maximum performance

Advanced python tracing
Trace python statement execution and syscalls invoked during that simultaneously

Do some learning...
Just realized how needless the 'ls' has been... This version is also multilingual, since there is no need to grep for a special key word ("nothing"/"nichts"/"rien"/"nada"...). And it makes use of all the available horizontal space.

Getting the last argument from the previous command

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"

Get AWS temporary credentials ready to export based on a MFA virtual appliance
You might want to secure your AWS operations requiring to use a MFA token. But then to use API or tools, you need to pass credentials generated with a MFA token. This commands asks you for the MFA code and retrieves these credentials using AWS Cli. To print the exports, you can use: `awk '{ print "export AWS_ACCESS_KEY_ID=\"" $1 "\"\n" "export AWS_SECRET_ACCESS_KEY=\"" $2 "\"\n" "export AWS_SESSION_TOKEN=\"" $3 "\"" }'` You must adapt the command line to include: * $MFA_IDis ARN of the virtual MFA or serial number of the physical one * TTL for the credentials


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