As I was debugging an issue at work related to http headers being forwarded by haproxy I used a couple tcpdump commands that was great, storing here for future reference .
tcpdump -s 1024 -l -A | grep X-Forwarded-For tcpdump -s 1024 -l -A src 192.168.9.56 or dst 192.168.9.56
First one will print lines containing X-Forwarded-For, second one let you filter on src and/or destination .
Note that tcpdump by default does not include 127.0.0.1 or ::1 ( lo ) .
[518950.884021] usb 2-4: new low speed USB device number 23 using ohci_hcd [518951.108559] input: Trust GM-4200 Gamer Optical Mouse as /devices/pci0000:00/0000:00:0b.0/usb2/2-4/2-4:1.0/input/input24 [518951.108681] generic-usb 0003:145F:011A.0016: input,hidraw1: USB HID v1.11 Mouse [Trust GM-4200 Gamer Optical Mouse] on usb-0000:00:0b.0-4/input0
It’s kind of frustrating with dmesg timestamps. It basically show [seconds.nanoseconds] since last boot … that’s really accurate, and totally useless for humans that can’t do that math in their heads .
This guy at code.saghul.net wrote a great python script as a solution.
With reference to one of the comments at that blog, an even more elegant solution would be to simply use /var/log/kern.log , it’s already there 🙂
chsh is great when you need to change default login shell for a lot of users.
Something like:
for f in $(grep home /etc/passwd | grep -v ftp | cut -d':' -f1) ; do chsh -s /bin/sh $f ; done
You would of course have to refine the grep line to sort out accounts you don’t want to change default login shell for .
Not some Lord of the rings geek program, simply a great utility to change line break for files. In Debian install it with
# apt-get install tofrodos # man tofrodos
COOL, Linus Thorvald and his team has released Linux Kernel 3.0 linuxjournal.com post and it’s now available in stable from kernel.org .
Nice command to find how much ram my graphics card has. Use ‘lspci’ to get the pci id and throw it back to lspci like this:
joar@juno:~$ lspci | grep VGA 00:02.0 VGA compatible controller: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller (rev 09) joar@juno:~$ lspci -v -s 00:02.0 00:02.0 VGA compatible controller: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller (rev 09) Subsystem: Lenovo Device 3a02 Flags: bus master, fast devsel, latency 0, IRQ 30 Memory at f4000000 (64-bit, non-prefetchable) [size=4M] Memory at d0000000 (64-bit, prefetchable) [size=256M] I/O ports at 1800 [size=8] Capabilities: <access denied> Kernel driver in use: i915 Kernel modules: i915 joar@juno:~$