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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"

useful tail on /var/log to avoid old logs or/and gzipped files
with discard wilcards in bash you can "tail" newer logs files to see what happen, any error, info, warn...

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

Archive all SVN repositories in platform indepenent form
Use of hotcopy for safety/stability of the backups.

Display 16 largest installed RPMs in size order, largest first
Interesting to see which packages are larger than the kernel package. Useful to understand which RPMs might be candidates to remove if drive space is restricted.

Convert seconds to [DD:][HH:]MM:SS
Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

list files recursively by size

Get information on your graphics card on linux (such as graphics memory size)
Loop is needed if you have more then one card.

Delete all aliases for a network interface on a (Free)BSD system
The example command deletes all aliases for network interface 'em0' assuming that the aliases have netmask of 255.255.255.255 and the master IP has some other netmask (such as 255.255.255.0). See here -> http://my.galagzee.com/2009/07/22/deleting-all-network-interface-aliases/ for more on the rationale of this command.

Slow down IO heavy process
Some IO intensive process make the system unresponsive. This function periodically starts/stops a process, which hopefully releases some resources for other activities. This function is useful when ionice is not available


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