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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

Tail postfix current maillog and grep for "criteria"
Tail curren postfix maillog.

Update twitter from command line without reveal your password
Update twitter from commandline, without revealing your password and without having to type it interactively. You 'll need to put a line "machine twitter.com login TWITTERUSER password TWITTERPASS" in $HOME/.netrc and better chmod 600 that file.

Determine next available UID
Typical usage would be in a script that would want the next open UID in a range (in this case 500-600)

Count items in JSON array
Pipe any JSON to jq, then count with the appropiate expression and use the | length on the array

Print without executing the last command that starts with...
It happens that sometime you remember that you used a special command short time before and you want to check the command again. WIth this command you can just put the beginning of a command and then bash will look for you and it will print back safely withou executing

Add Password Protection to a file your editing in vim.
While I love gpg and truecrypt there's some times when you just want to edit a file and not worry about keys or having to deal needing extra software on hand. Thus, you can use vim's encrypted file format. For more info on vim's encrypted files visit: http://www.vim.org/htmldoc/editing.html#encryption

Convert unix timestamp to date

Route outbound SMTP connections through a addtional IP address rather than your primary

Exclude inserting a table from a sql import
Starting with a large MySQL dump file (*.sql) remove any lines that have inserts for the specified table. Sometimes one or two tables are very large and uneeded, eg. log tables. To exclude multiple tables you can get fancy with sed, or just run the command again on subsequently generated files.


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