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Create the signature base string required for a Twitter stream feed
This is the SECOND command in a set for five that are needed for a Twitter stream feed. This command creates variable "b", the so-called "base string" required for oauth in Twitter stream feed requests. (The 256 char limit prevents giving it a better name) We use five environment variables created by a previous step: id, k1, once, ts and k3. The five environment variables are created in a separate command, please see my other commands. For more information on the signature base string, see dev.twitter.com/apps, click on any app (or create a new one) and then go to the "OAuth Tool" tab.

Download SSL server certificate with opsnessl
Useful when we need to create new certificate for site when current one is near expiry. This downloaded cert can be used to provide organisational data directly to new cert. using below command. e.g. openssl x509 -x509toreq -in /tmp/example.com.cert -out example.com.csr -signkey example.com-key.pem

Find the package that installed a command

Extract JPEG images from a PDF document
This will extract all DCT format images from foo.pdf and save them in JPEG format (option -j) to bar-000.jpg, bar-001.jpg, bar-002.jpg, etc. Inspired by http://stefaanlippens.net/extract-images-from-pdf-documents

Show a curses based menu selector
Not so much handy by itself, but very nice in shell scripts. This makes you a handy ncurses based checklist. Much like terminal installers, just use the arrow keys and hit 'Space' to adjust the selections. Returns all selected tags as strings, with no newline at the end. So, your output will be something like: "one" "two" "three" "four" "etc" For those who prefer bash expansion over gratuitious typing: $ whiptail --checklist "Simple checkbox menu" 12 35 3 $(echo {one,two,three,four}" '' 0"} ) Things to note: The height must includes the outer border and padding: add 7 to however many items you want to show up at the same time. If the status is 1, it will be selected by default. anything else, will be deselected.

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Create a mirror of a local folder, on a remote server
Create a exact mirror of the local folder "/root/files", on remote server 'remote_server' using SSH command (listening on port 22) (all files & folders on destination server/folder will be deleted)

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

Create a .png from a command output and upload to ompdlr.org, give URI
Create a .png from output command or whatever, the upload and give URI from ompdlr.org

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"


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