Commands by 4fthawaiian (5)

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Debug your makefile
Say your dependencies specified in your Makefile (or dates on your source files) is causing 'make' to skip some source-files (that it should not) or on the other other end, if it is causing make to always build some source-files regardless of dates of target, then above command is handy to find out what 'make' thinks of your date v/s target date-wise or what dependencies are in make's view-point. The egrep part removes the extra noise, that you might want to avoid.

Top Command in batch mode
running top command in batch mode. it is usefull if you want to redirect the output in a file.

Figure out what shell you're running

check open ports without netstat or lsof

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

Complex string encoding with sed
Pipe | avoid escaping occurences problems in using sed and make it easier to use

get all Amazon cloud (amazonws etc) ipv4 subnets

VI config to save files with +x when a shebang is found on line 1
Add this to .vimrc to automatically give scripts with a shebang (e.g., #!/usr/bin/perl) executable permissions when saving. Found @ http://stackoverflow.com/questions/817060/creating-executable-files-in-linux/817522#817522

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

Set laptop display brightness
Run as root. Path may vary depending on laptop model and video card (this was tested on an Acer laptop with ATI HD3200 video). $ cat /proc/acpi/video/VGA/LCD/brightness to discover the possible values for your display.


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