Commands by John_W (10)

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do something else while waiting for an event, such as reboot
until (ssh root@10.1.1.39 2> /dev/null); do date; sleep 15; done In this case will execute "date" then "sleep 15" until we are able to ssh into server, such as after a reboot Could also be like: until ( ping 10.1.1.39 1> /dev/null); do echo "server 10.1.1.39 is down"; sleep 15; done

Stop Flash from tracking everything you do.
Brute force way to block all LSO cookies on a Linux system with the non-free Flash browser plugin. Works just fine for my needs. Enjoy.

Extract a remote tarball in the current directory without having to save it locally

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

Change display resolution
-s must be a valid resolution. You can get a list of valid (and supported) resolutions via `xrandr`.

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"

See system users

uniq without pre-sorting
Reads stdin, and outputs each line only once - without sorting ahead of time. This does use more memory than your system's sort utility.

ping a host until it responds, then play a sound, then exit
This allows for sleeping in between pings. Also, espeak needs to be installed.

Show the total number of changes that every user committed to a Subversion repository
This saves Subversion's log output as XML and then runs an XQuery over it. This is standard XQuery 1.0 and should therefore also work with other XQuery processors. I have tested it with Zorba (http://www.zorba-xquery.com). XQilla (http://xqilla.sourceforge.net) also does it, but you'd have to save the query to a file and then execute "xqilla filename.xq". The query first finds all distinct authors and then, for each author, sums up the number of paths they have changed in each commit. This accounts for commits of multiple changes at once. The indenting space in all lines from the second one seems to be due to a bug in Zorba.


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