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Who has the most Apache connections.
This will tell you who has the most Apache connections by IP (replace IPHERE with the actual IP you wish to check). Or if you wish, remove | grep -c IPHERE for the full list.

list files recursively by size

determine if tcp port is open
Requires netcat.

find text in a file
this will find text in the directory you specify and give you line where it appears.

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

Flush and then immediately start watching a file
This is useful for keeping an eye on an error log while developing. The !^ pulls the first arg from the previous command (which needs to be run in a sub-shell for this shortcut to work).

set history file length
set how many commands to keep in history Default is 500 Saved in /home/$USER/.bash_history Add this to /home/$USER/.bashrc HISTFILESIZE=1000000000 HISTSIZE=1000000

Find out the last times your system was rebooted (for the duration of wtmp).

Convert seconds to [DD:][HH:]MM:SS
Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }


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