Watch a file for changes and copy/sync it to a remote host

entr

  • works on Linux and Mac OS
  • install entr
ls -b [file]... | entr -p scp /_ targethost:/destination/folder/

inotify

  • works only on Linux
  • it does not work if the file is replaced rather than changed.
  • install inotify-tools
F="filename" eval 'inotifywait -m -e close_write $F | while read E; do echo -e $(date +"%F %T") $E; scp $F root@targethost:/destination/folder/; done;'

Resize root partition on UEFI/GPT machines

It assumes you want to resize root partition (/) on a virtual machine and the partition you want to resize is the last one that has data. Swap would be ok if it’s last.

Example (disk already resized from 5GB to 20GB):

Disk /dev/sda: 41943040 sectors, 20.0 GiB
Logical sector size: 512 bytes
Disk identifier (GUID): 7DCC138E-820C-42FA-AFB4-3E9A89946AFB
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 10485726
Partitions will be aligned on 2048-sector boundaries
Total free space is 4029 sectors (2.0 MiB)

Number  Start (sector)    End (sector)  Size       Code  Name
   1            2048          194559   94.0 MiB    EF00
   2          194560         6639615   3.1 GiB     8300  root
   3         6639616        10483711   1.8 GiB     8200  swap
  1. resize the disk
  2. reboot?
  3. swapoff -a
  4. gdisk /dev/sda
  5. make all new sectors usable
    • go to expert mode with command ‘x’
    • use command ‘e’ to relocate backup data structures to the end of the disk
    • go back to menu (‘m’)
  6. delete partitions sda3 and sda2
  7. re-create partition sda2, type 8300
    • it should start from the same sector to preserve the data
    • leave some space at the end for the swap
  8. re-create sda3, type 8200
  9. optional: rename the partitions with the old (or new) names
  10. write parition table to disk
  11. mkswap /dev/sda3
  12. edit /ets/fstab and update UUID of the swap partition, it probably changed
  13. reboot
  14. resize2fs /dev/sda2

Ranger Cheatsheet

ranger is a console file manager with vim key bindings

Most Used Keyboard Shortcuts

ttag toggle
g nnew tab
TABnext tab
qquit tab
d Ddelete
d dcut
y yyank / copy
p ppaste
p opaste overwrite
arename
g hgo home
/search
Sopen shell
ropen with …
Eedit
d ccount the size
[move up in the parent directory
]move down in the parent directory
'bookmarks
``last directory bookmark
z htoggle show hidden files
o rsort reverse
o msort by mtime
o nsort natural / by name
Rreload this directory
SPACEselect under cursor
vinvert selection / select all

Raspberry Pi (rpi) – Disable WiFi and/or Bluetooth

Open /boot/config.txt and add to the end of the file:

# disable wifi
dtoverlay=pi3-disable-wifi

# disable bt
dtoverlay=pi3-disable-bt

Reboot!

Alternatively you can blacklist kernel modules for wifi and/or bluetooth

Create /etc/modprobe.d/raspi-blacklist.conf and copy this:

## wifi
blacklist brcmfmac
blacklist brcmutil

## bt
blacklist btbcm
blacklist hci_uart

Reboot!