Linux Tips & Tricks

disk UUID's

Get complete info about partitions, type and if mounted:

lsblk -f

Also useful:

blkid -s UUID -o value /dev/sda

PDF tools

pdfjoin , no rotate

pdfjoin --rotateoversize false

two a5 in one a4

pdfnup a5.pdf a5.pdf --nup '2x1' 

Note: pdfnup is part of texlive-extra-utils package

overlay a “draft” or other watermark…

pdftk in.pdf multistamp stamp.pdf output out.pdf

a4 to a3 or other scaling

gs -o output.pdf -sDEVICE=pdfwrite -sPAPERSIZE=a4 -dFIXEDMEDIA -dPDFFitPage -dCompatibilityLevel=1.4 input.pdf

Reset keyboard

setxkbmap -model pc104 -layout us

Debian/ubuntu package modify and (re)build


Asterisk click-to-call

Virtual Machines

VDI <--> RAW

Convert VDI (or other) to raw disk:

$ VBoxManage clonehd astlinu256.vdi ast.raw –format RAW

Resize raw disk

$ qemu-img resize ast.raw 100M

Note that partition table is not altered (to be done manually)


qemu-img create filename.img 100M

qemu-system-i386 -cdrom cdrom.iso -hda disk1.img -hdb disk2.img -m 128 -boot d

See also

Socat / YPort

socat PTY,link=/dev/YPort TCP:

obtain mac address with sed

With ifconfig

ifconfig eth0 | head -n 1 | sed 's/.*HWaddr //g' | xargs

With ip

ip addr show dev eth0 | tail -n1 | sed 's/.*ether //' | sed 's/brd.*//' | xargs



SUBSYSTEM=="tty", ATTRS{idVendor}=="ABCD", ATTRS{idProduct}=="1234", ATTRS{serial}=="12345678", SYMLINK+="mydevice"

To obtain serial number:

udevadm info -a -n /dev/ttyUSB1 | grep serial


Note : udevadm returns ALL usb hierarchy devices, thus the serial returned is not necessarily the one of the hw device! Actually many (chinese) converters do not have serial number programmed.



To set a minimum clearance for all selected objects


To convert from vector image (postscript) to pcb format:

$pstoedit -xscale 0.1 -yscale 0.1 -f "pcb: -stdnames -tshiftx -0.0947 -tshifty -0.886 -grid 0.1 -mm -snapdist 0.4" file.pcb

Appunti vari

^M = CR = d13 = '\r'
^J = LF = d10 = '\n'

Mount images (iso, img, ...)

ISO: # mount -o loop disk1.iso /mnt/disk

IMG: fdisk -l /path/to/image to obtain block size and start of the partition, then

# mount -o loop,offset=NNNN disk1.iso /mnt/disk

for example block size = 512, start block is 2048, so: # mount -o loop,offset=1048576 disk1.iso /mnt/disk

Find large files

find . -type f -size +10000k -exec ls -lh {} \; | awk '{ print $8 ": " $5 }'

hardware info


cat /proc/cpuinfo

show tcp/udp sockets

Listening or connected

$ netstat -tapnu

ssh connection with port tunnelling

To have a port forwarded through the ssh connection

ssh user@destinationhost -psshport -L[localip:]localport:destip:destport

sshport : the port where the ssh daemon listens
localip : localip where to bind (optional, localhost is default)
localport : local port to bind
destip : destination ip where i want to connect, seen by the destinationhost's point of view, could be localhost if same machine as destinationhost, or its local ip, or another ip in the network
destport : the destionation port where i want to connect

howto show 'dd' progress

Sending a USR1 signal to a running `dd' process makes it print I/O statistics to standard error and then resume copying.

$ dd if=/dev/zero of=/dev/null&amp; pid=$! $ kill -USR1 $pid; sleep 1; kill $pid

You can add “watch” to this one:

1) find $pid for you dd process: $ps aux|grep dd

2) show progress, by running: $watch kill -USR1 $pid


Someone suggested to give a look to

Or: (definitely best solution)

$ dd if=/dev/zero of=/dev/null&amp; bs=1M status=progress

rsync quick ref

classical backup rule

rsync –delete –perms –numeric-ids -aruv –bwlimit=100 –protect-args [SOURCE] [DEST]

–exclude ' ' to exclude some file

–password-file=FILE the password should be wrote in a plain text file 'FILE'

-u, –update skip files that are newer on the receiver

-C, –cvs-exclude auto-ignore files in the same way CVS does

add TTF fonts

Simply copy the fonts in the ~/.fonts folder (of the X11 user), create it if doesn't exist.

Video conversions

How to convert Matrioska Video (mkv) to standard mpeg containter (avi)

avconv -i file.mkv -b:video 4000k file.avi


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