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Search for a process by name
ps and grep is a dangerous combination -- grep tries to match everything on each line (thus the all too common: grep -v grep hack). ps -C doesn't use grep, it uses the process table for an exact match. Thus, you'll get an accurate list with: ps -fC sh rather finding every process with sh somewhere on the line.

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

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" }

Run a ext4 file system check and badblocks scan with progress info
Nothing fancy, just a regular filesystem scan that calls the badblocks program and shows some progress info. The used options are: -c ? check for bad sectors with badblocks program -D ? optimize directories if possible -f ? force check, even if filesystem seems clean -t ? print timing stats (use -tt for more) -y ? assume answer ?yes? to all questions -C 0 ? print progress info to stdout /dev/sdxx ? the partition to check, (e.g. /dev/sda1 for first partition on first hard disk) NOTE: Never run fsck on a mounted partition!

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"

backup directory. (for bash)

Remove color codes (special characters) with sed

Apply new patch for a directory (originDir)

Block known dirty hosts from reaching your machine
Blacklisted is a compiled list of all known dirty hosts (botnets, spammers, bruteforcers, etc.) which is updated on an hourly basis. This command will get the list and create the rules for you, if you want them automatically blocked, append |sh to the end of the command line. It's a more practical solution to block all and allow in specifics however, there are many who don't or can't do this which is where this script will come in handy. For those using ipfw, a quick fix would be {print "add deny ip from "$1" to any}. Posted in the sample output are the top two entries. Be advised the blacklisted file itself filters out RFC1918 addresses (10.x.x.x, 172.16-31.x.x, 192.168.x.x) however, it is advisable you check/parse the list before you implement the rules

clone directory structure
dir1 and all its subdirs and subdirs of subdirs ... but *no files* will be copied to dir2 (not even symbolic links of files will be made). To preserve ownerships & permissions: $ cp -Rps dir1 dir2 Yes, you can do it with $ rsync -a --include '*/' --exclude '*' /path/to/source /path/to/dest too, but I didn't test if this can handle attributes correctly (experiment rsync command yourself with --dry-run switch to avoid harming your file system) You must be in the parent directory of dir1 while executing this command (place dir2 where you will), else soft links of files in dir2 will be made. I couldn't find how to avoid this "limitation" (yet). Playing with recursive unlink command loop maybe? PS. Bash will complain, but the job will be done.


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