Unix and Linux Tips

Minggu, 27 September 2009

Unix Tip: BACKUP CRITICAL SYSTEM FILES

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3156 - September 27, 2009

http://www.ugu.com/sui/ugu/show?tip.today

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BACKUP CRITICAL SYSTEM FILES

Before modifying critical system files, make a backup copy using the date as an extension:

$ cp /etc/hosts /etc/hosts.971006

If you keep a number of these they provide a potentially valuable archive as well as a means of finding out any changes that have been made and when.

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Sabtu, 26 September 2009

Unix Tip: QUICK UNALIAS

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3155 - September 26, 2009

http://www.ugu.com/sui/ugu/show?tip.today

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QUICK UNALIAS

If you have aliased a command to somehting and want to quickly unalias it, preceed the name with a backslash, '\', and it will have the original meaning. For example, if you have 'rm' aliased to 'rm -i' and want to remove one entire directory without being prompted for each file, you would do:

$ \rm -fr dirname

where 'dirname' is the directory you want to trash.

This tip generously supported by: khamsi@kmrmail.kmr.ll.mit.edu

Unix Guru Universe - www.ugu.com - tips@ugu.com - Copyright 1994-2001
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Jumat, 25 September 2009

Unix Tip: A REFRESHING X

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3154 - September 25, 2009

http://www.ugu.com/sui/ugu/show?tip.today

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A REFRESHING X

If your X display gets messed up somehow,run a program called "xrefresh" in your X11R6 bin directory, it will clean up the display so you don't need to kill X.

This tip generously supported by: kev@zebradale.com

Unix Guru Universe - www.ugu.com - tips@ugu.com - Copyright 1994-2001
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Kamis, 24 September 2009

Unix Tip: GENERATE RANGES OF NUMBERS

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3153 - September 24, 2009

http://www.ugu.com/sui/ugu/show?tip.today

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GENERATE RANGES OF NUMBERS

Sometimes it is necessary to generate a range of numbers for further use within a command pipe or shell script. This can be done with some simple sh-code:

------------------------ CUT HERE ------------------

#! /bin/sh

# range - Generate of numbers.

lo=$1
hi=$2

while [ $lo -le $hi ]
do
echo -n $lo " "
lo=`expr $lo + 1`
done

------------------------ CUT HERE ------------------

It can now be used a way like:

for i in `range 69 4711`; do <some code>; done

This tip generously supported by: ulli@ucrc.org

Unix Guru Universe - www.ugu.com - tips@ugu.com - Copyright 1994-2001
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Rabu, 23 September 2009

Unix Tip: HOW TO KILL YOUSELF FAST!

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3152 - September 23, 2009

http://www.ugu.com/sui/ugu/show?tip.today

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HOW TO KILL YOUSELF FAST!

Here is a Tip on how to kill yourself fast.

% kill -9 -1

This could also be used to kill another user:

# su - johndoe -c 'kill -9 -1'

NOTE: UGU does not recommend Admins going on a killing spree, but only when it is necessary.

Unix Guru Universe - www.ugu.com - tips@ugu.com - Copyright 1994-2001
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Selasa, 22 September 2009

Unix Tip: NULL IT FAST

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3151 - September 22, 2009

http://www.ugu.com/sui/ugu/show?tip.today

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NULL IT FAST

Here is the fastest way to truncate a file to zero bytes in a bourne or korn shell.

$ > /var/log/messages

This is a good method, if the file has to be truncated, but is opened by another process. For example, if you want to truncate /var/log/messages, which is held open by syslogd...

This tip generously supported by: ulli@ucrc.org

Unix Guru Universe - www.ugu.com - tips@ugu.com - Copyright 1994-2001
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