Commands using grep (1,935)

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Remove a range of lines from a file

Find usb device
I often use it to find recently added ou removed device, or using find in /dev, or anything similar. Just run the command, plug the device, and wait to see him and only him

Host cpu performance
Measure the cpu performance: In-case if the cpu is thermal throttling then you can find it using this command. Check the first line of the output. Example: Doing md5 for 3s on 16 size blocks: 11406892 md5's in 2.98s ? #(When cpu is not throttling) Doing md5 for 3s on 16 size blocks: 110692 md5's in 2.98s ?? #(When cpu is thermal throttling) Practical use case: Once we had cooling outage in data center which caused thermal throttling in some of the worker nodes. We used this tool to prove that some servers are not performing well because of the cpu thermal throttling.

chmod - change file permissions of a file to be similar of another

Burn CD/DVD from an iso, eject disc when finished.
cdrecord -scanbus will tell you the (x,y,z) value of your cdr (for example, mine is 3,0,0)

Update dyndns.org with your external IP.
This is great if you are behind a router that does not support dynamic dns updates! Example: AT&T u-verse gateway... Put this in a script and run it as a cron job.

Read funny developer comments in the Linux source tree
These are way better than fortune(6).

Generate random valid mac addresses
First set the variable $hexchars: $hexchars="0123456789ABCDEF" Change the number in the first for loop if you need less then 1200 mac addresses

A DESTRUCTIVE command to render a drive unbootable
Overwrites the boot sector. Since this doesn't overwrite any data, you can usually recover by re-creating the partition table exactly the same as before you zeroed it. This can also help sometimes if you install a new drive in a Windows machine which can't read it.

Graphical tree of sub-directories with files
The command finds every item within the directory and edits the output so that subdirectories are and files are output much like the tree command


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