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Start screen in detached mode
Start screen in detached mode, i.e., already running on background. The command is optional, but what is the purpose on start a blank screen process that way? It's useful when invoking from a script (I manage to run many wget downloads in parallel, for example).

check open ports without netstat or lsof

Resume an emerge, and keep all object files that are already built
For Gentoo: If you do not use this command, portage will fetch the source again, and rebuild the hole application from the top. This command make portage keep all files that ar allready built

Print every Nth line
Sometimes commands give you too much feedback. Perhaps 1/100th might be enough. If so, every() is for you. $ my_verbose_command | every 100 will print every 100th line of output. Specifically, it will print lines 100, 200, 300, etc If you use a negative argument it will print the *first* of a block, $ my_verbose_command | every -100 It will print lines 1, 101, 201, 301, etc The function wraps up this useful sed snippet: $ ... | sed -n '0~100p' don't print anything by default $ sed -n starting at line 0, then every hundred lines ( ~100 ) print. $ '0~100p' There's also some bash magic to test if the number is negative: we want character 0, length 1, of variable N. $ ${N:0:1} If it *is* negative, strip off the first character ${N:1} is character 1 onwards (second actual character).

Find the package that installed a command

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

Exclude grep from your grepped output of ps (alias included in description)
Surround the first letter of what you are grepping with square brackets and you won't have to spawn a second instance of grep -v. You could also use an alias like this (albeit with sed): alias psgrep='ps aux | grep $(echo $1 | sed "s/^\(.\)/[\1]/g")'

Show top running processes by the number of open filehandles they have
I think I could cut down the number of pipes here, any suggestions?

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"

Display current bandwidth statistics
ifstat, part of ifstat package, is a tool for displaying bandwidth and other statistics. The -n option avoid to display header periodically, the -t option put a timestamp at the beginning of the line. Works for me on Debian and CentOS


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