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Shows all block devices in a tree with descruptions of what they are.
This can be useful when a large remove operation is taking place.
The lifehacker way: http://lifehacker.com/software/top/geek-to-live--encrypt-your-data-178005.php#Alternate%20Method:%20OpenSSL
"That command will encrypt the unencrypted-data.tar file with the password you choose and output the result to encrypted-data.tar.des3. To unlock the encrypted file, use the following command:"
$ openssl des3 -d -salt -in encrypted-data.tar.des3 -out unencrypted-data.tar
Give the Speed and Link status of eth# 0-3. This is sort of what mii-tool does, but eth-tool is better, yet lacks device discovery.
Show all commands having the part known by you.
Eg:
$apropos pdf | less
With this command you can get a previous or future date or time. Where can you use this? How about finding all files modified or created in the last 5 mins?
touch -t `echo $(date -d "5 minute ago" "+%G%m%d%H%M.%S")` me && find . -type f -newer me
List all directories created since last week?
touch -t `echo $(date -d "1 week ago" "+%G%m%d%H%M.%S")` me && find . -type d -cnewer me
I'm sure you can think of more ways to use it. Requires coreutils package.
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"
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
rsync'ing an empty directory over a directory to be deleted recursively is much faster than using rm -rf, for various reasons. Relevant only for directories with really a lot of files.