Friday, October 12, 2007

Raising Elephants Is So Utterly Boring

Taken from http://en.wikipedia.org/wiki/Magic_SysRq_key
"Raising Elephants Is So Utterly Boring" is a mnemonic device for remembering a keystroke sequence that should be used as an alternative to hitting the power button if a Linux system should ever freeze and need to be rebooted.
Alt + SysRq + R – takes the keyboard out of raw mode.
Alt + SysRq + E – terminates all processes (except init).
Alt + SysRq + I – kills all processes (except init).
Alt + SysRq + S – synchronizes the disk.
Alt + SysRq + U – remounts all filesystems read-only.
Alt + SysRq + B – reboots the machine.
Or it can be remembered as "BUSIER" in reverse.
"Raising Skinny Elephants Is Utterly Boring" is an alternative mnemonic for the same series of keystrokes, though changing the position of the disk synchronization to before terminating and killing all processes.
Regardless of which of the above hotkey sequences are chosen, they should be entered in slow succession, giving the system a chance to complete earlier steps before moving on to subsequent ones. Typing the sequence slowly may allow the system to safely terminate most or all processes before the more drastic kill command is invoked. Also, to minimize the chance of data corruption, it is a good idea to wait between the disk synchronization command and the unmount and finally the reboot command.
An alternative to issuing the REISUB/RSEIUB keystrokes is to just press Alt + SysRq + R, followed by Ctrl + Alt + Del. This is the equivalent of issuing a shutdown now command at a root console; it does take a short while for the system to shut down after the Ctrl + Alt + Del keystroke. However, not all Linux systems support this easier method.


Special thanks to my sister :)

starting program from terminal in background

So, if you want to start the program and to use terminal afterwards, you just need to put "&" character at the end of the line
so, for example, if you just want to call skype, then you write skype&

It is simple thing, but sometimes one just forget this as a option :)

Embedded Font Problems with PDF files

Some of you may have encountered some problem of embedded fonts with PDF
files. All fonts are embedded with the following command (Linux):

ps2pdf14 -dPDFSETTINGS=/prepress -dEmbedAllFonts=true file.ps file.pdf

This is done thanks to my colleague, Alex :)

Thursday, October 11, 2007

RPMs

This can be useful for those who had problems installing programs in openSUSE 10.2 (in my case, YasT is somehow crashing very often).
To install rpm package:
rpm -ivh packagename
To upgrade the package:
rpm -Uvh packagename
To remove the package:
rpm -e packagename

If you not sure that your package is installed, there is a way to see it:
rpm -qa packagename
There can be problems to remember full name of the package since it is having all those version numbers etc.etc. so instead of writing out whole name, you can do next command:
rpm -qa | grep SomeKeywordOfWantedPackage

Cheers!

Monday, October 1, 2007

How to merge multiple pdf files into one

Linux command:
gs -dNOPAUSE -sDEVICE=pdfwrite -sOUTPUTFILE=Merged.pdf -dBATCH *.pdf

Wednesday, September 12, 2007

how to install source programs in linux

How often does it happen to you to download a new program which happen not to be any kind of debian package or something similar that you just need to use option install.

Beforehand, look for README text which will probably tell you how to install the program

Often for those, source code applications there are couple of steps to do in order to install them.
1. open terminal window (I use yakuake, in which u can open terminal just by pressing F12)
2. go to directory of your new, just downloaded application
3. run ./configure command - it looks if your system is ready to install application. It is checking for packages it needs to get its installed (newly downloaded application)
4. Look for comments at the end. If there is some comment like, error: 'libxyz' is not found, than you have to look for package that contains this library. I use adept-manager to search for those, and google if I fail to find it there.
5. when you finally install all packages needed, you proceed to next step
6. run make command
7. run make install command
8. finito, last two commands should run smoothly, if there are still some problems, consult google with keyword as your error text.

Tuesday, September 11, 2007

Yakuake

very cool console which starts when u press F12.
alt-f2 and then write yakuake

Friday, September 7, 2007

To put translate absolute link into relative links

Search for: http://((.*)/)*(.*)"
Replace with: \3"

Useful when you have downloaded all file from particular page, but you need this webpage for navigation through files.

Download a list of files (list of their links)

If you have list of files you need to download, there is a way to do that automatically.
so, assuming every line is starting with http:... in any kind of text editor you replace option to replace every "http" with "wget -c -t5 -l1 http".
Then Save the list-file as a download.sh.
When you do that, then go to terminal/console window, type chmod 777 download.sh
and then ./download.sh

It then downloads everything from the list into current folder.

Monday, September 3, 2007

HTTPS website download

linux command
wget -r --http-user=USERNAME --http-password=PASSWORD https://www.SOMEPAGE.com

A lot of download managers and windows freeware website downloaders claim that they can download from https website, but somehow they always fail to login to page.