Author: mfeilner

This has probably been done a thousand times and ways, and much better than my humble fiddling. Consider this my memory pad for later.

I am doing some scripted pdf magic with files that come in from the scanner. They are either too big for web use, wrong format, not the right orientation (user error) or similar. So here’s a little collection:

Convert all (huge) PDFs into small ones with ghostscript (assuming ./Z-OLD for old versions exists):

for i in *.pdf; do gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/ebook -dNOPAUSE -dQUIET -dBATCH -sOutputFile=$i-small.pdf $i; mv $i Z-OLD/; rename .pdf-small.pdf .pdf *-small.pdf; done

Convert all PNGs in working directory into small PDFs (assuming ./png exists):

for i in *.png; do convert $i $i.pdf; mv $i png/; gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/ebook -dNOPAUSE -dQUIET -dBATCH -sOutputFile=$i-small.pdf $i.pdf; rename .png-small.pdf .pdf *.png-small.pdf; rm *.png.pdf; done

Concatenate PDFs into one file (the last argument is the new outputfile):

pdfunite A.pdf B.pdf C.pdf ABC.pdf

A lazy “rotate all” script that helps me if I put the paper on the scanner the wrong way. Leaves four versions of every pdf it finds, but 90/180/270° degrees tilted to the original.

#!/bin/bash
INFILE=ls.txt
ls *pdf -1 > $INFILE
while IFS=”²” read -r line
do
PDF=`basename $line | rev | cut -c 5- | rev`
#left turn
pdftk “$line” cat 1-endwest output “$PDF”_left.pdf
#right turn
pdftk “$line” cat 1-endeast output “$PDF”_right.pdf
#turn 180 degrees:
pdftk “$line” cat 1-endsouth output “$PDF”_upsidedown.pdf
done <$INFILE

And yes, I know, there’s better ways. Worx 4 me, I guess. 🙂

That one little moment when the last of the systems that had failed for years to wake up on LAN finally gives up and does the job. I literally have no idea what went wrong on this little media station in the past, but a fresh install of Opensuse Tumbleweed fixed it. We’ve been looking into the BIOS so many times, systematically, comparing with its twin sibling, didn’t find a mistake. And also the NetworkManager dispatcher script was installed. I gave up and did a fresh Linux install. All I had to do then was adding this script: 

#!/bin/bash
# /etc/NetworkManager/dispatcher.d/wol
#
#
# wol dispatcher script for NetworkManager
#
#
IFNAME=enp2s0
if [ “$2“ = “up” -a “$1“ = “$IFNAME“ ]; then
sleep 2
/usr/sbin/ethtool -s $IFNAME wol g
fi

… and make it executable (chmod a+x), done. Oh, make sure that the line starting with “IFNAME” (line 8) contains YOUR device’s name, not the random generated by your distributor and that the script really ends up in /etc/NetworkManager/dispatcher.d/wol.

Now my little upgrade script (don’t do this on production machines!) wakes up and updates the media station every morning while we are sleeping (all relevant data changed):

#!/bin/bash
# /usr/sbin/wakeup-update-mediastation
#
# Wakeup and update MediaStation
wol a8:a1:23:3e:g7:39
sleep60
ssh 192.168.0.222 ‘sudo zypper ref && sudo zypper dup -y -l –allow-vendor-change‘
sleep20
ssh 192.168.0.222 ‘sudo sync; sudo poweroff‘
logger “Mediastation successfully updated“

It’s invoked by the cron job: 

0 6 * * * /usr/sbin/wakeup-update-mediastation

Your mileage may vary when it comes to user priviledges (sudo or ssh as root, make sure you do the right thing!)

Barrier: A Free, Open-Source and Cross-Platform Alternative to Synergy

“You’ve probably heard of Synergy before. If you didn’t, Synergy is a piece of software that allows you to shares one mouse and one keyboard between multiple computers. A great piece of software that costs $29 for the basic version and $39 for the pro version. If you’d love to have the capabilities that Synergy provides but don’t want to fork over $29, you should check out Barrier which is free, open-source and cross-platform. Synergy started as an open source project. So the guys over at Barrier forked that original Synergy project, updated it and kept it’s minimalistic design.”