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list block devices
Shows all block devices in a tree with descruptions of what they are.

Export a directory to all clients via NFSv4, read/write.
This exports a directory to the world in read/write mode. It is useful for quick, temporary NFS exports. Consider restricting the clients to a subnet or to specific hosts for security reasons (the client can be specified before the colon). On the client: mount -t nfs4 hostname:/ /mountpoint To terminate all of the exports (after unmounting on the client): exportfs -u -a Leave out the fsid=0 option if you don't want NFSv4. This works under recent versions of Linux.

Always tail/edit/grep the latest file in a directory of timestamped files
zsh only If you have this command in your history, you can always re-run it and have it reference the latest file. The glob matches all timestamped files and then the resulting array is sorted by modification time (m) and then the first element in the sorted array is chosen (the latest)

Check to make sure the whois nameservers match the nameserver records from the nameservers themselves
Change the $domain variable to whichever domain you wish to query. Works with the majority of whois info; for some that won't, you may have to compromise: domain=google.com; for a in $(whois $domain | grep "Domain servers in listed order:" --after 3 | grep -v "Domain servers in listed order:"); do echo ">>> Nameservers for $domain from $a

list files recursively by size

check site ssl certificate dates
remotely connects to an https site, fetches the ssl certificate and displays the valid dates for the cert

Find broken symlinks and delete them
recursively deletes all broken symlinks using zsh globbing syntax.

backup a directory in a timestamped tar.gz
creates a tar.gz with a name like: backup20090410_173053.tar.gz of a given directory. this file was made 10 April 2009 at 5:30:53pm see date's man page to customize the timestamp format

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 Solid Archive (best compression) with 7z
Creates a solid archive with the highest possible compression (Ultra). Advantage of 7z is that it will use all the processor cores to create the archive. (Ok. at least version 9.04 does)


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