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If you set noclobber to on, bash won't allow redirection to overwrite existing files .
$ set -o noclobber command turn the option on (default it s off ) .
You can still append information but not overwrite the file .to turn it back off use : $ set +o noclobber .
I use it because i overwrite a file by accident , after thought , content of the file was very important , creating a one more file mean nothing for my hard disk (we are not anymore on the 64 k memory time) , but content of file is far much important . What we call exeprience :(
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
This command displays a simple menu of file names in the current directory. After the user made a choice, the command invokes the default editor to edit that file.
* Without the break statement, the select command will loop forever
* Setting the PS3 prompt is optional
* If the user types an invalid choice (such as the letter q), then the variable $f will become an empty string.
* For more information, look up the bash's select command
awk is evil!
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
Another way of doing it that's a bit clearer. I'm a fan of readable code.