Openunix.eu

Little hacking of all kind...

• Set Xterm's title
  echo -ne "\033]2;My_term_name\007"
  
  

• Split a pdf file or cut off one,two pages

  pdftk original_50_pages_long_document.pdf cat 8-12 output what_I_wanted.pdf

• Apply changes from one file (database) to another.

  $ diff ldap_sorted.txt mysql_sorted.txt >master.diff
$ patch patching file mysql_sorted.txt
Reversed (or previously applied) patch detected! Assume -R? [n] y
$ diff ldap_sorted.txt mysql_sorted.txt
$ (empty line indicates the two files are identical again)


• Get rid of ^L character

  For example using sed you can do something like this (by typing Ctrl-V and Ctrl-L):
Code:
sed 's/^L//' file

or by means of the octal code:
Code:
sed 's/\o14//' file



• Watching network with tcpdump

  # tcpdump -n #simplet monitor of network traffic

# tcpdump -nnv -A |grep ".80" #shows traffic on port 80



• Which TCP ports are open on the BSD server

  # netstat -nat | grep LISTEN |grep tcp\




• Who is doing what on the server

  $ w



• Runing X remotely

  on the server:
$ export DISPLAY 192.16.1.3:0.0
one the laptop:
$ xhost +192.16.1.1
on the server:
$ k3b
on the laptop:
The K3b gui appears



• Caja/Nautilus scripts
  

  $ cat /home/petr/.config/caja/scripts/zmensi_pdf 
  #!/bin/bash
  xterm -e /home/petr/.bin/zpdf
  
  $ cat /home/petr/.bin/zpdf 
  echo "vybiram tyto soubory:"
  echo "$CAJA_SCRIPT_SELECTED_FILE_PATHS"
  sleep 3
  for i in $CAJA_SCRIPT_SELECTED_FILE_PATHS 
  do
  echo "zmensuji $*"
  h=`echo "$i" |sed -e 's/\.pdf/\-ok\.pdf/g' `
  gs -sDEVICE=pdfwrite -dNOPAUSE -dBATCH -dPDFSETTINGS=/ebook -sOutputFile="$h" "$i"
  echo "$i" je nyní zmenšen jako "$h"
  done
  sleep 10
  
  $ cat /home/petr/.config/caja/scripts/zmensi_foto 
  #!/bin/bash
  xterm -e /home/petr/.bin/zjpeg
  
  $ cat /home/petr/.bin/zjpeg
  #!/bin/bash
  echo "vybiram tyto soubory:"
  echo "$CAJA_SCRIPT_SELECTED_FILE_PATHS"
  for i in $CAJA_SCRIPT_SELECTED_FILE_PATHS ;
  do 
  if test -f $i
  then
  # zmensi a zapise do noveho souboru
  #convert -resize 800x600 $i  
  # zmensi a prepise puvodni soubor
  mogrify -resize 1024x768 $i
  echo "zmensil jsem obrazek $i ." ; 
  fi
  done 
  sleep 10