Commands using ssh (347)

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Exclude a string with awk

Get your commandlinefu points (upvotes - downvotes)
Like command #4845, prints score, number of entries, and average score.

External IP (raw data)
can be used in script like : echo $(wget -qO- http://utils.admin-linux.fr/ip.php)

Mount a VMware virtual disk (.vmdk) file on a Linux box
This does not require you to know the partition offset, kpartx will find all partitions in the image and create loopback devices for them automatically. This works for all types of images (dd of hard drives, img, etc) not just vmkd. You can also activate LVM volumes in the image by running $vgchange -a y and then you can mount the LV inside the image. To unmount the image, umount the partition/LV, deactivate the VG for the image $vgchange -a n then run $kpartx -dv to remove the partition mappings.

Updated top ten memory utilizing processes (child/instance aggregation) now with percentages of total RAM
Prints the top 10 memory consuming processes (with children and instances aggregated) sorted by total RSS and calculates the percentage of total RAM each uses. Please note that since RSS can include shared libraries it is possible for the percentages to add up to more that the total amount of RAM, but this still gives you a pretty good idea. Also note that this does not work with the mawk version of awk, but it works fine with GNU Awk which is on most Linux systems. It also does not work on OS X.

Remove all the characters before last space per line including it

Calculate days on which Friday the 13th occurs (inspired from the work of the user justsomeguy)
Friday is the 5th day of the week, monday is the 1st. Output may be affected by locale.

Port Knocking!
Knock on ports to open a port to a service (ssh for example) and knock again to close the port. You have to install knockd. See example config file below. [options] logfile = /var/log/knockd.log [openSSH] sequence = 3000,4000,5000 seq_timeout = 5 command = /sbin/iptables -A INPUT -i eth0 -s %IP% -p tcp --dport 22 -j ACCEPT tcpflags = syn [closeSSH] sequence = 5000,4000,3000 seq_timeout = 5 command = /sbin/iptables -D INPUT -i eth0 -s %IP% -p tcp --dport 22 -j ACCEPT tcpflags = syn

Count number of bytes that are different between 2 binary files

Quickly build ulimit command from current values
It is helpful to know the current limits placed on your account, and using this shortcut is a quick way to figuring out which values to change for optimization or security. Alias is: $ alias ulimith="command ulimit -a|sed 's/^.*\([a-z]\))\(.*\)$/-\1\2/;s/^/ulimit /'|tr '\n' ' ';echo" Here's the result of this command: $ ulimit -c 0 -d unlimited -e 0 -f unlimited -i 155648 -l 32 -m unlimited -n 8192 -p 8 -q 819200 -r 0 -s 10240 -t unlimited -u unlimited -v unlimited -x unlimited $ ulimit -a core file size (blocks, -c) 0 data seg size (kbytes, -d) unlimited scheduling priority (-e) 0 file size (blocks, -f) unlimited pending signals (-i) 155648 max locked memory (kbytes, -l) 32 max memory size (kbytes, -m) unlimited open files (-n) 8192 pipe size (512 bytes, -p) 8 POSIX message queues (bytes, -q) 819200 real-time priority (-r) 0 stack size (kbytes, -s) 10240 cpu time (seconds, -t) unlimited max user processes (-u) unlimited virtual memory (kbytes, -v) unlimited file locks (-x) unlimited


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