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Search for a string inside all files in the current directory
options: -n line nbrs, -i ignore case, -s no "doesn't exist", -I ignore binary args: * for all files of current dir (not hidden), .[!.]* for all hidden files I don't include by default the -R (recursive) option, which is not always useful. You add it by hand when needed.

get a random 0/1, use it for on/off, yes/no
use it to add a random boolean switch to your script

Renaming a file without overwiting an existing file name
Sometimes in a hurry you may move or copy a file using an already existent file name. If you aliased the cp and mv command with the -i option you are prompted for a confirmation before overwriting but if your aliases aren't there you will loose the target file! The -b option will force the mv command to check if the destination file already exists and if it is already there a backup copy with an ending ~ is created.

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

Copy specific files recursively using the same tree organization.
This command has been used to overwrite corrupted "entries" files of a corrupted subversion working copy. Note the --files-from input format.

Get Cisco network information
This gives you lots of nifty Cisco network information like VLAN tag, port and switch information.

Benchmark SQL Query
Benchmark a SQL query against MySQL Server. The example runs the query 10 times, and you get the average runtime in the output. To ensure that the query does not get cached, use `RESET QUERY CACHE;` on top in the query file.

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"

Get line number of all matches in a file

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


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