Scripts for scanning

There is an interview with Friedrich Duerrenmatt where he calls the
photocopier the greatest invention ever. It allows him to cut up
manuscripts, glue the pieces together, and then copy them for more
cutting and gluing.

I have seen the benefit of writing by hand too. I like to write answers
to exercises by hand on blank pages and then scan them to PDF files.
I would scan a 3-page A5 document like so:

   $ jscan a5
   $ jscan a5
   $ jscan a5
   $ jpdf a5
   $ ls
   01.jpg 02.jpg 03.jpg out.pdf

I have bundled the scripts here using a script like the one shown in
"The UNIX Programming Environment" by Brian Kernighan and Rob Pike.
To unbundle them into your current directory (overwrites!), run

   cat 2023-334.txt | sed -n '/^# sh from here to unbundle$/,$p' | sh

You don't even need to save a copy of this file. At the time of writing,
you can replace "cat 2023-334.txt" with any of the following two:

   curl https://dkalak.de/feed/2023-334.txt
   echo /feed/2023-334.txt | nc dkalak.de 70

# sh from here to unbundle
echo jscan 1>&2
cat >jscan <<'End of jscan'
#!/bin/sh
# jscan: scan a page to jpeg

case $# in
1|2) ;;
*  ) echo 'Usage: jscan format [file[.jpg]]' 1>&2; exit 1
esac

case $1 in
a4 ) x=210; y=297 ;;
a5 ) x=148; y=210 ;;
a5l) x=210; y=148 ;;
a6 ) x=105; y=148 ;;
a6l) x=148; y=105 ;;
*  ) echo 'Bad page format, pick a4 a5[l] a6[l]' 1>&2; exit 1
esac

case $2 in
''   ) for i in `seq -w 99`; do [ -f $i.jpg ] || break; done
       file=$i.jpg ;;
*.jpg) file=$2     ;;
*    ) file=$2.jpg ;;
esac

device=$(scanimage -L | grep -m1 Samsung | cut -d' ' -f2 | tr -d \`\')

case $device in
'') echo 'No device found' 1>&2; exit 1
esac

scanimage --format=jpeg --resolution 300 --mode=Color \
          -d $device -x $x -y $y >$file
End of jscan
echo jpdf 1>&2
cat >jpdf <<'End of jpdf'
#!/bin/sh
# jpdf: convert jpeg files to pdf

case $# in
1|2) ;;
*  ) echo 'Usage: jpdf format [out[.pdf]]' 1>&2; exit 1
esac

case $1 in
a4|a5|a6) format=$1 ;;
*) echo 'Bad page format, pick a4 a5 a6' 1>&2; exit 1
esac

case $2 in
''   ) file=out.pdf ;;
*.pdf) file=$1      ;;
*    ) file=$1.pdf  ;;
esac

convert -density 72 -page $format *.jpg $file
End of jpdf
exit

Written by Daniel Kalak in 2023. Verbatim copying and distribution of
this entire article are permitted worldwide, without royalty, in any
medium, provided this notice is preserved. Copying and distribution of
the given shell scripts, with or without modification, are permitted
worldwide, without royalty, in any medium. This file is offered as-is,
without any warranty. EOF