Commands using sleep (289)

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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"

Debug redirects between production reloads
Watches the headers of a curl, following any redirects and printing only the HTTP status and the location of the possible redirects.

Detect illegal access to kernel space, potentially useful for Meltdown detection
Based on capsule8 agent examples, not rigorously tested

Test your total disk IO capacity, regardless of caching, to find out how fast the TRUE speed of your disks are
Depending on the speed of you system, amount of RAM, and amount of free disk space, you can find out practically how fast your disks really are. When it completes, take the number of MB copied, and divide by the line showing the "real" number of seconds. In the sample output, the cached value shows a write speed of 178MB/s, which is unrealistic, while the calculated value using the output and the number of seconds shows it to be more like 35MB/s, which is feasible.

Run a command when a file is changed

Create a CD/DVD ISO image from disk.
Many like to use 'dd' for creating CD/DVD iso images. This is bad. Very bad. The reason this is, is 'dd' doesn't have any built-in error checking. So, you don't know if you got all the bits or not. As such, it is not the right tool for the job. Instead, 'reaom' (read optical media) from the wodim package is what you should be using. It has built-in error checking. Similarly, if you want to burn your newly creating ISO, stay away from 'dd', and use: $ wodim -v -eject /path/to/image.iso

Silently deletes lines containing a specific string in a bunch of files
This command will find all occurrences of one or more patterns in a collection of files and will delete every line matching the patterns in every file

vimdiff local and remote files via ssh
Lifted from http://linux.spiney.org/remote_diff_with_vim_and_ssh which points out credits for the inspiration.

Remove newlines from output
?Cat and grep? You can use only grep ("grep \. filename"). Better option is awk.

Print just line 4 from a textfile
Prints the 4th line and then quits. (Credit goes to flatcap in comments: http://www.commandlinefu.com/commands/view/6031/print-just-line-4-from-a-textfile#comment.)


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