xauth extract cookiefilename :X
xauth merge cookiefilename
mdadm
:mdadm --create --verbose /dev/md0 --level=5 --raid-devices=3 /dev/sdX1 /dev/sdY1 /dev/sdZ1
cat /proc/mdstat
mdadm --detail --scan >> /etc/mdadm/mdadm.conf update-initramfs -u
echo check > /sys/block/mdX1/md/sync_action
cat /proc/mdstat
to monitor)sysctl dev.raid.speed_limit_min ; sysctl dev.raid.speed_limit_max
sysctl -w dev.raid.speed_limit_min=value
/etc/sysctl.conf
dev.raid.speed_limit_min = 50000 ## good for 4-5 disks based array ## dev.raid.speed_limit_max = 2000000 ## good for large 6-12 disks based array ### dev.raid.speed_limit_max = 5000000
mdadm
RAID:pvcreate -M2 /dev/md0 vgcreate -s 64 newvg /dev/md0 lvcreate -L 128G -n newlv newvg mkfs -t ext4 /dev/newvg/newlv
overlay
module is loaded (modprobe overlay)mount -t overlay -o lowerdir=ldir,upperdir=udir,workdir=wdir overlayfs overlaydir
This uses dm-crypt
LUKS support, which is all part of the kernel (I believe) (in Ubuntu
, make sure the lvm2
package is installed) :
dd if=/dev/urandom of=.diskimg bs=1M count=1024 losetup --find --show /home/rk4n3/.diskimg cryptsetup -c aes-xts-plain64:sha256 -s 512 -v -y luksFormat /dev/loopX cryptsetup luksOpen /dev/loopX diskname mkfs -t ext4 /dev/mapper/diskname mount /dev/mapper/diskname /home/rk4n3/sec
Here is similar, but for burning an encrypted DVD:
dd if=/dev/zero of=dvd.img bs=1M count=4400 losetup --find --show dvd.img cryptsetup -c aes-xts-plain64:sha256 -s 512 -v -y luksFormat /dev/loopX cryptsetup luksOpen /dev/loopX dvdimg mkisofs -l -r -allow-leading-dots -allow-lowercase -allow-multidot -J -joliet-long -o /dev/mapper/dvdimg dir2burn
Cleaning up after …
cryptsetup luksClose /dev/mapper/dvdimg losetup -d /dev/loopX
Mounting …
cryptsetup luksOpen /dev/sr0 yourdvdname mount -o ro /dev/mapper/yourdvdname /mount/point/dir
Run: xinput list
There will be a list that looks similar to:
⎡ Virtual core pointer id=2 [master pointer (3)] ⎜ ↳ Virtual core XTEST pointer id=4 [slave pointer (2)] ⎜ ↳ ETPS/2 Elantech Touchpad id=12 [slave pointer (2)] ⎜ ↳ Logitech USB Receiver id=15 [slave pointer (2)] ⎣ Virtual core keyboard id=3 [master keyboard (2)] ↳ Virtual core XTEST keyboard id=5 [slave keyboard (3)] ↳ Power Button id=6 [slave keyboard (3)] ↳ Video Bus id=7 [slave keyboard (3)] ↳ Video Bus id=8 [slave keyboard (3)] ↳ Power Button id=9 [slave keyboard (3)] ↳ Sleep Button id=10 [slave keyboard (3)] ↳ AT Translated Set 2 keyboard id=11 [slave keyboard (3)] ↳ MSI WMI hotkeys id=13 [slave keyboard (3)] ↳ Logitech USB Receiver id=14 [slave keyboard (3)]
Run this command for the ID that matches trackpad device:
xinput set-prop 12 “Device Enabled” 0
At the command-line:
mount -t tmpfs -o size=512m tmpfs /home/someone
In the /etc/fstab
:
tmpfs /home/someone tmpfs nodev,uid=1801,gid=100,size=512M 0 0
export PS1='\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\ $'
On one machine:
nc -vvlnp 12345 > /dev/null
On the other:
dd if=/dev/zero bs=1M count=1K | nc -vvn x.x.x.x 12345
Epson ESC/POS command reference: https://reference.epson-biz.com/modules/ref_escpos/index.php?content_id=72
Nice article here: https://mike42.me/blog/2015-03-getting-a-usb-receipt-printer-working-on-linux …
Use dmesg
to verify that usblp
has seen the printer (lpX
device should be in /dev/usb
):
dmesg [12724.994550] usb 8-4: new full-speed USB device number 5 using ohci-pci [12725.168956] usb 8-4: New USB device found, idVendor=04b8, idProduct=0e03 [12725.168963] usb 8-4: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [12725.168968] usb 8-4: Product: TM-T20 [12725.168971] usb 8-4: Manufacturer: EPSON [12725.168975] usb 8-4: SerialNumber: .... [12725.175114] usblp 8-4:1.0: usblp1: USB Bidirectional printer dev 5 if 0 alt 0 proto 2 vid 0x04B8 pid 0x0E03
Here's PHP code for a simple output:
/* ASCII constants */ const ESC = "\x1b"; const GS="\x1d"; const NUL="\x00"; /* Output an example receipt */ echo ESC."@"; // Reset to defaults echo ESC."E".chr(1); // Bold echo "FOO CORP Ltd.\n"; // Company echo ESC."E".chr(0); // Not Bold echo ESC."d".chr(1); // Blank line echo "Receipt for whatever\n"; // Print text echo ESC."d".chr(4); // 4 Blank lines /* Bar-code at the end */ echo ESC."a".chr(1); // Centered printing echo GS."k".chr(4)."987654321".NUL; // Print barcode echo ESC."d".chr(1); // Blank line echo "987654321\n"; // Print number echo GS."V\x41".chr(3); // Cut exit(0);
export PS1=$'\e[32m\u262F ${USER}@\e[33m${SYS} \u2622\u25AC\u25B6\e[0m '
export PS1=$'\e[32m\u250F\u2501\e[33m ${USER}@${SYS} \e[31m\u2622\e[36m ${PWD}\n\e[32m\u2517\u2501\u276F\u276F\u276F\e[0m '
export PS1=$'\e[32m\u250F\u2501\e[33m ${USER}@$(uname -n) \e[31m\u2622\e[36m \w\n\e[32m\u2517\u2501\u276F\u276F\u276F\e[0m '
Interesting things powered by linux
Links: Tech Info … Mantis Area