Commands tagged canon (3)

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Restrict the use of dmesg for current user/session
Linux offers an interesting option to restrict the use of dmesg. It is available via /proc/sys/kernel/dmesg_restrict. You can check the status with: $ cat /proc/sys/kernel/dmesg_restrict Alternatively you can use sysctl: $ sudo sysctl -w kernel.dmesg_restrict=1 To make your change persistent across reboot, edit a fille in /etc/sysctl.d/.

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

Convert JSON to YAML
Requires installing json2yaml via npm: npm install -g json2yaml (can also pipe from stdin) Ref: https://www.npmjs.com/package/json2yaml

Process command output line by line in a while loop
This snippet allows to process the output of any bash command line by line.

Awk: Perform a rolling average on a column of data
Sometimes jittery data hides trends, performing a rolling average can give a clearer view.

list block devices
Shows all block devices in a tree with descruptions of what they are.

Work out numerical last month
Work out last months numerical value.

Continue a current job in the background

List all installed Debian packages
Should work on all systems that use dpkg and APT package management.

Rename files in batch


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