Filip Rooms

Sysadmin related notes

Usually extracts from other website; local copy not to have to read the full page again...

Useful command: "nm" to check symbols in an object file (i.e., compiled source to be linked)

Update fails/ package database inconsistent

dpkg --configure -a

KDE windows have no border, buttons, ...

clean .kde dir (profile corrupt)

Note on installation of linux GRUb

Careful where to install GRUB when installing different systems: Grub installs might overwrite each others system files when not careful.

Installation of linux with propriatary drivers

Configure non-free repositories first before propriatary drivers can be installed (like from nVidia, needed for the 3D desktop effects).
Careful when using propriatary drivers (eg graphical cards, printers, ...) on linux: automatical updates don't necessary respect dependencies between the system and the drivers, so update might ruin your system.

Install XV

Source code: http://www.trilon.com/xv/ However, not free software and not maintained since 1994... So, compile it yourself from source:

Make sure standard development files are installed (e.g. kdebase-dev for kubuntu 8.04, needed for e.g. string.h and stdio.h) as well as the X11 development lib (xv uses it).
in ./tiff/RANLIB.csh: is not necessary and jsut causes problems, so remove the first line (#!/bin/csh -f) as well as all uncommented lines.

in xv.h: remove around line 199 the part

#ifndef __NetBSD__
     extern char *sys_errlist[];     /* this too... */
#  endif

make a dir /usr/local/man/man1 for the xv man page

That's it, now it should compile and install (worked for me for Mandriva 2008.1 and kubuntu 8.04)

Rename multiple files

(from http://www.debian-administration.org/articles/150) Move files with extensions in uppercase "JPG" to lowercase "jpg":

for i in *.JPG; do mv "$i" "${i/.JPG}".jpg; done

Convert multiple files with ImageMagick (no name keeping)

(from http://studio.imagemagick.org/pipermail/magick-users/2007-March/019326.html)

convert *.tif image%02d.jpg

Check if CD/DVD burning was successful

(from http://www.g-loaded.eu/2006/10/07/verify-a-burned-cddvd-image-on-linux/)

Command line burning of iso
```
growisofs -Z /dev/hdc=sep2006.iso 
```
(/dev/hdc is CD/DVD device; can be different)

Show in how many 2kb blocks the file is written

echo $(( $(ls -l sep2006.iso | awk '{ print $5 }') / 2048 ))

Compute md5sum from burned data:
- Find on which device your CD writer was mounted using "/etc/mtab". If this was "/dev/scd2", check with "isoinfo -d -i /dev/scd2"
- Compute the sum using "dd if=/dev/scd2 bs=2048 | head -c 728111104 | md5sum", with:
  - "/dev/scd2" the actual device for your CD writer
  - 2048 the block size, as returned by "isoinfo" from one of the previous steps: Logical block size is: 2048 in my case.
  - 728111104 the file size of your iso file, as you can read with a simple "ls -al" in the directory with the iso file.

Winmail.dat

Open with tnef reader, like ktnef (which is a TNEF viewer/extractor, which fully integrates with the KDE environment (mime types, ...) and can be registered as opening application for e-mail clients).

Directory permission value

R = 4 read permission
W = 2 write permission
X = 1 execute permission

So chmod 754 file.ext results in giving permission for read/write/execute to yourself (7=4+2+1), read and execute permission to people of your group and read permission to other users of the system.

Wifi under linux

http://ndiswrapper.sourceforge.net/

Recursive search for files containing multiple strings

find | grep -e "string1" -e "string2"
Need to put backslash before a point ("\.") to have a point in the search string.