Unix and Linux Tips

Unix Tip: BACKUP INDEX LOCATIONS

2012-01-29T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3277 - January 29, 2012

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BACKUP INDEX LOCATIONS

Couple words on your backups index.

1) When doing backups on your systems
make sure that your backup indexes are
not stored on the same disks that you
may need to recover files from. If you
loose the disk that the files are on then
you still have your backups safe. If
you loose the disks with your backup
indexes, your files are still okay and
the users will be able to work. You can
then spend the day scanning your indexes
from tape.

2) Make sure that you backup your indexes
occasionally using tar, dump, cpio or
something else other than your normal backup
software.

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GURU UNIVERSE. ALL TIPS ARE "USE AT YOUR OWN RISK". UGU ADVISES THAT
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Unix Tip: DELETING BLANK LINES USING GREP

2012-01-28T01:42:00.001-08:00

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UNIX HOT TIP

Unix Tip 3276 - January 28, 2012

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DELETING BLANK LINES USING GREP

To delete a blank line using a grep command you can use the next
command :-

grep -v "^ *$" file-y > file-x

where file-y is the input files has blank lines and file-x will
be the output file ( excluding the blank lines ).

if we use ( grep -v "^$" ) only , the blanck line which include
spaces will not be removed.

This tip generously supported by: yousif_morckos@yahoo.com

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Unix Tip: THE BAD AND THE GOOD

2012-01-27T01:42:00.001-08:00

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UNIX HOT TIP

Unix Tip 3275 - January 27, 2012

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THE BAD AND THE GOOD

I cringe anytime I see someone code inefficiently. Here are
three of the most common mistakes, followed by a better way to
do the same thing.

Bad: cat somefile | grep something
Better: grep something somefile
Why: You're running one program (grep) instead of two (cat
and grep).

Bad: ps -ef | grep something | grep -v grep
Better: ps -ef | grep [s]omething
Why: You're running two commands (grep) instead of three (ps
and two greps).

Bad: cat /dev/null > somefile
Better: > somefile
Why: You're running a command (cat) with I/O redirection,
instead of just redirection.

Although the bad way will have the same result, the good way is
far faster. This may seem trivial, but the benefits will really
show when dealing with large files or loops.

This tip generously supported by: sec@nbnet.nb.ca

Unix Guru Universe - www.ugu.com - tips@ugu.com - Copyright 1994-2001
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Unix Tip: SUSPEND A VI SESSION FOR SHELL

2012-01-26T01:42:00.001-08:00

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UNIX HOT TIP

Unix Tip 3274 - January 26, 2012

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SUSPEND A VI SESSION FOR SHELL

Ever want to run some shell commands while doing a vi edit
session? Like, "what's the name of that file" I want to use in
this script I'm making?

Instead of exiting vi; doing the ls filenamepart*, and going
back into vi, you can from a vi session:

enter ":", then enter "shell".

This suspends the vi session and gives you a command prompt
where you can use any shell command. When finished, enter the
"exit" command and you will be returned to the vi session.

This tip generously supported by: cwhenske@gatx.com

Unix Guru Universe - www.ugu.com - tips@ugu.com - Copyright 1994-2001
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Unix Tip: BC AND NOT BEFORE AD

2012-01-25T01:42:00.001-08:00

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UNIX HOT TIP

Unix Tip 3273 - January 25, 2012

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BC AND NOT BEFORE AD

Fire up our old friend and often forgotten bc.

% bc

Enter your arthimetic expression

20+20

Will return

but the best part is, use the
"obase" and "ibase" commands for all
your conversion needs.

For example, type:

obase=16

then type:

255

This will output "FF".

Next, if you type:

obase=2

Then a dot (or period), it stands for
"the last number")

It will return "11111111", that's 255 in binary!

If you need hex to dec,
just type "ibase=16" and "obase=10"

Have fun!

Unix Guru Universe - www.ugu.com - tips@ugu.com - Copyright 1994-2001
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Unix Tip: LISTING FILES BY SIZE

2012-01-24T01:42:00.001-08:00

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UNIX HOT TIP

Unix Tip 3272 - January 24, 2012

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LISTING FILES BY SIZE

If you want to have a listing of the
files sorted by size, you can use the
following command(s), it will list
the files in decrease order. if you
need to do the same thing recursively,
you could use the second one.

ls -l | grep ^- | sort -nr -k 5 | more

ls -lR | grep ^- | sort -nr -k 5 | more

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Unix Tip: WHERE AM I ALWAYS

2012-01-23T01:42:00.001-08:00

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UNIX HOT TIP

Unix Tip 3271 - January 23, 2012

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WHERE AM I ALWAYS

In csh, if you always want to know
where you are, put in your .cshrc-file
the following 2 lines:

alias sp 'set prompt="`hostname`:`pwd`> "'
alias cd 'cd \!*;sp'

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Unix Tip: WHO SENT ME MAIL

2012-01-22T01:42:00.001-08:00

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UNIX HOT TIP

Unix Tip 3270 - January 22, 2012

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WHO SENT ME MAIL

To know who all have sent you mail.

---------------CUT HERE ----------
#!/bin/sh

: ${USER:=`expr "\`LANG=C id\`" : 'uid=[0-9]*($[^)]*$.*'`}

for MBox in /var/mail/$USER /usr/spool/mail/$USER ""
do
[ -r "$MBox" ] && break
done

[ -z "$MBox" ] && exec echo "No mailbox"

exec grep "^From " "$@" "$MBox"

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

This tip generously supported by: pradeep@cdacb.ernet.in

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Unix Tip: STRINGS - OLD BUT A GOODIE

2012-01-21T01:42:00.001-08:00

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UNIX HOT TIP

Unix Tip 3269 - January 21, 2012

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STRINGS - OLD BUT A GOODIE

To check content of an object
file(binary file ) we can't use vi
or cat command, for that use strings
command.

% strings [name of binary file]

It will print all the printable strings
present in object file. Basically
strings command looks for ASCII strings
in executable file and print it.

Great for core files and other binary
error files

This tip generously supported by: aggarami@pcsbom.patni.com

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Unix Tip: RUN DAILY WITH AT

2012-01-20T01:42:00.001-08:00

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UNIX HOT TIP

Unix Tip 3268 - January 20, 2012

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RUN DAILY WITH AT

UNIX provides a command called "at"
which can be used to run jobs according
to the specfied time.

To run a particular job in every hour,
every day use the following set of
commands in a file called "at.sh" which
will be executed recursively everyday.

########### CUT HERE ##################

#! /usr/bin/sh

# dt is a variable used to store
# current date

dt=`date | cut -c5-10`

# tm is a variable used to store
# current time

tm=`date | cut -c12-13`

while [ $tm -le 23 ]
do

# "at" is the command ad -f is the
# option used to execute a specified
# file. "file Name" should be an
# executable file.

at -f ./"file Name" $tm $dt
tm=`expr $tm + 1`
done

# With out manual intervention, automatic
# change over to the next day's job
# scheduling

at -f ./"File Name" 2358 $dt
dt=`expr $dt + 1`
at -f ./at.sh 0002 $dt

########### CUT HERE ##################

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Unix Tip: FIND THOSE HIDDEN FILES

2012-01-19T01:42:00.001-08:00

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UNIX HOT TIP

Unix Tip 3267 - January 19, 2012

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FIND THOSE HIDDEN FILES

Finding only hidden files
(starting with .) in a directory.

ls -a | grep "^\." OR
ls -a | awk '$0~/^\./ {print $0}'

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Unix Tip: RUN ON LAST SUNDAY

2012-01-18T01:42:00.001-08:00

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Unix Tip 3266 - January 18, 2012

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RUN ON LAST SUNDAY

If you want a job to run on the last
sunday of every month, you can use
the following syntax from within cron:

18 * * * 0 [`date "+%d"` -gt 24] && /path/to/script

i.e. on sundays at 18:00 check if
the day of the month is greater than
24 - if so run the job (if 23 is
specified the job will run on the last
2 sundays of the month)

NOTE: There back-ticks around the date
command, not single quotes.

This tip generously supported by: duncan.ferguson@egg.com

Unix Guru Universe - www.ugu.com - tips@ugu.com - Copyright 1994-2001
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Unix Tip: SIMPLE MASK OVERLOOKED

2012-01-17T01:42:00.001-08:00

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UNIX HOT TIP

Unix Tip 3265 - January 17, 2012

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SIMPLE MASK OVERLOOKED

Another way to CD to the long directory.

Works in both csh and ksh

cd too*

Will change to the directory "toobigtotype"
As long as there is only one ocurrance
of the word too....

This is great when there is only
one sub directory within a directory,
just use:

cd *

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Unix Tip: AUTO WORD COMPLETION

2012-01-16T01:42:00.001-08:00

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UNIX HOT TIP

Unix Tip 3264 - January 16, 2012

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AUTO WORD COMPLETION

In tcsh, the TAB key will automatically
complete any name in the current
directory for any application (for pico,
cd, rm, chown)... It will even complete
paths from root.

Soo... If you want to open your .cshrc
from root you do..

"pico /ho"[TAB] -> "pico /home/"
Then continue with "yuo"[tab] -> "yourusername"
Then you get "pico /home/yourusername/"
And then type ".cs"[TAB] -> ".cshrc"
So in the end you get "pico /home/yourusername/.cshrc"
In a lot less stokes...

But say there are 2 users called
yourusername and yourothername.

Well, then the shell will beep, and if
you hit TAB again, you will get a listing
off all the files that start with "you".
You can then continue to the point where
the names differ, and then hit TAB.

This also works for commands.

Unix Guru Universe - www.ugu.com - tips@ugu.com - Copyright 1994-2001
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Unix Tip: CHANGE THE SUFFIX

2012-01-15T01:42:00.001-08:00

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UNIX HOT TIP

Unix Tip 3263 - January 15, 2012

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CHANGE THE SUFFIX

If you want to change the suffix of
multiple files, you can't do:

% mv *.abc *.def

However the following shell script
can be used to do the required
opperation:

***

Change all *.abc file to *.def the
following shell script would work:

#!/bin/sh
for f in *.abc; do
mv $f `basename $f .abc`.def
done

How it works:

for f in *.abc; do

Set up a look for all files ending
in .abc, and each time around setup
$f as the filename

mv $f `basename $f.abc`.def

`basename $f .abc` takes the filename
in $f and removes any trailing occurences
of .abc, we then append .def to the result
and the resulting command becomes
"mv file.abc file.def"

done

Ends the "for" loop above.

Under "csh" or "tcsh" a similar thing could be done with:

foreach f in ( *.abc )
mv $f `basename $f .abc`.def
end

This tip generously supported by: pwain@liberate.com

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

Unix Tip: DELETING BLANK LINES USING GREP

2012-01-14T01:42:00.001-08:00

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UNIX HOT TIP

Unix Tip 3262 - January 14, 2012

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DELETING BLANK LINES USING GREP

For thos who are not familiar with
awk, but still want a quick and easy
way of removing blank lines from a
flat ascii file, remember that the
use of 'cat' in conjuction with
'grep' is just as effective.

cat file1 | grep -v '^$' >file2
mv -f file2 file1

This tip generously supported by: dave_tomkins@tands.co.uk

Unix Guru Universe - www.ugu.com - tips@ugu.com - Copyright 1994-2001
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Unix Tip: LIMIT THE SIZE OF DATA AREA

2012-01-13T01:42:00.001-08:00

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UNIX HOT TIP

Unix Tip 3261 - January 13, 2012

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LIMIT THE SIZE OF DATA AREA

You can limit the size of "data area"
using ulimit and limit.

Under sh or ksh:
$ ulimit -d SIZE_IN_KB

Displays all current resource limits
$ ulimit -a

under csh or tcsh:
$ limit datasize SIZE_IN_KB

Displays all current resource limits
$ limit

For example:
$ ulimit -d 141073
$ ulimit -a

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

Unix Tip: PROBE-SCSI-ALL and IOSTAT

2012-01-12T01:42:00.001-08:00

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UNIX HOT TIP

Unix Tip 3260 - January 12, 2012

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PROBE-SCSI-ALL and IOSTAT

If you want to do probe-scsi-all
when the system is online, you
can do it by running the following
command:

# iostat -En

This is applicable for Solaris 2.6 on SPARC platform.

This tip generously supported by: bkumar@wipro.co.in

Unix Guru Universe - www.ugu.com - tips@ugu.com - Copyright 1994-2001
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Unix Tip: VI COPY FILE TO FILE

2012-01-11T01:42:00.001-08:00

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UNIX HOT TIP

Unix Tip 3259 - January 11, 2012

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VI COPY FILE TO FILE

Here is how to copy the required number
of lines from one file to another in
VI editor. First use the following
key combinations in the source file.

Press ESCAPE
Press Shift "(Shift double quotes)
Press a
Press the number of lines you want to copy
press y followed by another y

Now press " : " (COLON) to get the vi prompt.
Hit e "Destination file name"
Once you enter the Destination file
go to the line where you want the lines
copied to be inserted.

Press ESCAPE.
Press SHIFT "(Double quotes).
Press a.
Press p.

The lines get copied.

Unix Guru Universe - www.ugu.com - tips@ugu.com - Copyright 1994-2001
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Unix Tip: SEARCH SEVERAL FILES

2012-01-10T01:42:00.001-08:00

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UNIX HOT TIP

Unix Tip 3258 - January 10, 2012

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SEARCH SEVERAL FILES

To search several files for a
string which you know sparsely,
the following searching technique
would be useful:

#grep <first part>.*<second part>.*<... part> <filenames>
or,
#ls|xargs grep <first part>.*<second part>.*<... part>

This will print all the filenames
and lines which consists of
"<first part><0 to any number of
characters><second part><0 to any
number of characters><third part>
......"

For example, you want to search a
data structure among several header
files where it has been declared
not where it is being used.

If the data structure be XYZ, then
search will be:

#grep }.*XYZ <filenames>

because you know it might be how
XYZ has been declared,
struct {
.....
.....
} XYZ
You don't know exactly how many
blank characters are there
unless you count them. But when XYZ
will be used it will be
done as follows(for example):

XYZ *xyz;

and you don't want them to find out
as they will be coming
in several header or C files.

This tip generously supported by: dipakb@cdotd.ernet.in

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

Unix Tip: ARITHMETIC COMPARISON

2012-01-09T01:42:00.001-08:00

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UNIX HOT TIP

Unix Tip 3257 - January 9, 2012

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ARITHMETIC COMPARISON

In UNIX shell arithmetic comparison
is limited to integer values. Here
is a tip to compare floating values
using basic shell commands.

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

#! /bin/sh
# test shell script
n1="01.401"
n2="01.350"

function compareFloatSmall
{
sort -n <<: | head -1
$n1
$n2
:
}

function compareFloatGreat
{
sort -r -n <<: | head -1
$n1
$n2
:
}

small=$(compareFloatSmall $n1 $n2)
echo "Comparing $n1 to $n2: smaller $less"
great=$(compareFloatGreat $n1 $n2)
echo "Comparing $n1 to $n2: greater $great"

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

Alternatively you can use a small 'awk' program.

--------- CUT AGAIN HERE-----------
#! /bin/sh
# A couple of examples in awk.
n1="03.550"
n2="02.550"

echo "$n1 $n2" | awk '{
if ( $1 >= $2 ) print $1
if ( $1 <= $2 ) print $2
if ( $1 > $2 ) print $1
if ( $1 < $2 ) print $2
if ( $1 == $2 ) print $1, $2
}'
--------- CUT AGAIN HERE-----------

This tip generously supported by: sthackeray@netscape.net

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==========================================================================

Unix Tip: COPY A TREE WITH CPIO

2012-01-08T01:42:00.001-08:00

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UNIX HOT TIP

Unix Tip 3256 - January 8, 2012

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COPY A TREE WITH CPIO

Using standard UNIX tar to copy a
tree doesn't preserve the original
owner and group information for the
directories and files during the copy.
To do this, use find(1) piped to cpio(1)
this way:

% cd <source-directory>
% find . -depth -print | cpio -pudm <dest-directory>

This will create a mirror image of the
<source-directory> tree in <dest-directory>.

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

Unix Tip: AUTOMATICALLY SET DISPLAY

2012-01-07T01:42:00.001-08:00

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UNIX HOT TIP

Unix Tip 3255 - January 7, 2012

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AUTOMATICALLY SET DISPLAY

To set automatically the DISPLAY
variable after rlogin (csh):

if (`who am i | wc -w` > 5) then
setenv DISPLAY `who am i | cut -d"(" -f2 | cut -d")" -f1`:0.0
endif

May vary from flavor to flavor

This tip generously supported by: labrache@gaulois.cad.cea.fr

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

Unix Tip: ANOTHER SORT BY FILE SIZE

2012-01-06T01:42:00.001-08:00

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UNIX HOT TIP

Unix Tip 3254 - January 6, 2012

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ANOTHER SORT BY FILE SIZE

To sort certain files in the directory and to show
the biggest file first, do

$ du -a | sort -n -r | more

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

Unix Tip: FILE CONSISTANCY CHECK

2012-01-05T01:42:00.001-08:00

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UNIX HOT TIP

Unix Tip 3253 - January 5, 2012

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FILE CONSISTANCY CHECK

To check the number of feilds and the
consistancy of the file here is simple
command:

nawk -F "delimiter" '{print NF}' file_name|sort -u|more

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==========================================================================

Unix Tip: LOCK DOWN TELNET OR FTP

2012-01-04T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3252 - January 4, 2012

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LOCK DOWN TELNET OR FTP

When inbound access isn't required into
a system deny users Telnet or FTP access
do the following:

vi /etc/inetd.conf

Comment the line starts with Telnet or
FTP. Save the file and exit.

Stop and start the inetd daemon now by
following commands:

/etc/rc.d/init.d/inet stop

/etc/rc.d/init.d/inet start

(Your flavor may be /etc/init.d)

Now on nobody can telnet or FTP to your
server from outside network.

This tip generously supported by: avsrao_india@hotmail.com

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

Unix Tip: TRACKING OF LOGINS AND LOGOUTS

2012-01-03T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3251 - January 3, 2012

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TRACKING OF LOGINS AND LOGOUTS

In the .login file add the commands:
------------------------------------

echo login time `date` >> .daylogs/masterlog

grep -i "sun" .daylogs/masterlog > .daylogs/sunday.log
grep -i "mon" .daylogs/masterlog > .daylogs/monday.log
grep -i "tue" .daylogs/masterlog > .daylogs/tuesday.log
grep -i "wen" .daylogs/masterlog > .daylogs/wensday.log
grep -i "thu" .daylogs/masterlog > .daylogs/thursday.log
grep -i "fri" .daylogs/masterlog > .daylogs/friday.log
grep -i "sat" .daylogs/masterlog > .daylogs/saturday.log

In the .logout file add this line
-----------------------------------

echo logout time `date`>> .daylogs/masterlog

This script assumes you have a hidden
directory called .daylogs this helps keep it
out of sight and away from prying eyes and
if you keep root ownership of the directory
change the mode to:

chmod 744 .daylogs

This will not allow anyone to get in to the
directory to look around.

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

Unix Tip: IRIX: CHECK FOR NEW CONFIGS

2012-01-02T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3250 - January 2, 2012

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=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

IRIX: CHECK FOR NEW CONFIGS

SGI loves to try and simplify
your life with chkconfig switches
to toggle various services on
and off. After each upgrade,
DOUBLE check the chkconfig
switches. If something doesn't
work all of the sudden check
here.

For instance, tape drives in IRIX
are disabled by a default install.
To enable a tape subsystem:

# chkconfig ts on

# /etc/init.d/ts start

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

Unix Tip: OPERATING ON MULTIPLE FILES

2012-01-01T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3249 - January 1, 2012

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

OPERATING ON MULTIPLE FILES

Have you ever felt the need to perform a
set of operations on multiple files
simultaneously???

Here is a solution for that.

For instance, if it is required to perform
multiple operations like searching a string
(using grep), and executing an awk or perl
script etc, etc. on not just one file but a
set of files, use the following commands at
the unix prompt:

$<: foreach i (<file_list>)
? echo $i
? grep <search_pattern> $i > tmp
? awk -f awk_script tmp >> report
? ....
? ....
? end
$<:

The files list in the brackets can be either

* Specifically mentioned

* A unix variable which contains a list of
file names. For instance, the variable
"p" can be assigned all the files starting
with string "data" as follows:
set p = (data*)
Other examples are:
set g = `grep -l "Startpoint" * `
or
set all = *
(This assigns all file names in the current
directory to the variable "all" )

And its usage with the "foreach" command will
be as follows:

$<: foreach i ($all)
.....
.....
end

This tip generously supported by: lakshmi@virtualipgroup.com

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

Unix Tip: OPERATING ON MULTIPLE FILES

2011-12-31T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3613 - December 31, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

OPERATING ON MULTIPLE FILES

Have you ever felt the need to perform a
set of operations on multiple files
simultaneously???

Here is a solution for that.

$<: foreach i (<file_list>)
? echo $i
? grep <search_pattern> $i > tmp
? awk -f awk_script tmp >> report
? ....
? ....
? end
$<:

The files list in the brackets can be either

* Specifically mentioned

And its usage with the "foreach" command will
be as follows:

$<: foreach i ($all)
.....
.....
end

This tip generously supported by: lakshmi@virtualipgroup.com

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

Unix Tip: CHMOD THE SYSTEM

2011-12-30T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3612 - December 30, 2011

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=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

CHMOD THE SYSTEM

Along the lines of:

D O N O T D O T H I S!

Reports from several admins have
been made that dangerous users
who obtain root for the first
time enable full access to the
entire system. They are using
the following command:

# chmod -R 777 /

If you feel you have any
dangerous users, please advice
them of the dangers of executing
such a command.

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

Unix Tip: EXECUTE SCRIPT FROM NETSCAPE

2011-12-29T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3611 - December 29, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

EXECUTE SCRIPT FROM NETSCAPE

Do you want to execute a shell
script from your netscape
navigator ?

Go to EDIT>PREFERENCE>Applications
Edit or create an application
Choose the suffix (sh, csh)

Put "sh <%s" or "csh<%s" as application handler.

You can use the xtrem -e option
to get a intercacitive window shell into
your navigator.

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

Unix Tip: TASK ALERTS

2011-12-28T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3610 - December 28, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

TASK ALERTS

Have you ever started a long
running task, and after some time
decide you want to be alerted
when it finishes?

Add this to your .bashrc:

function aldo { while ps -ao pid | grep -q " ${1}$"; do sleep 1 ; done;
echo $'\a'; }

Then find the pid of a long
running process(say 253) and
on a different terminal:

501$ aldo 253

Will treat you to a pleasant beep when the task finishes.

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

Unix Tip: NO WRITES TO PASSWORD FILE

2011-12-27T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3609 - December 27, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

NO WRITES TO PASSWORD FILE

The normal mistake in a fit of quick
panic often by users is to be looking
at the /etc/passwd file and see that
there is "READ" access to the world
or "644" on the file.

Time and time again when they first
discover having root access they
change the permissions to:

chmod 000 /etc/passwd

D O N O T D O T H I S ! ! !

chmod 644 /etc/passwd

Is just fine!

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

Unix Tip: EAT YOUR PERL PIE

2011-12-26T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3608 - December 26, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

EAT YOUR PERL PIE

Mom always sed, "eat your Perl pie"!

A common task is to substitute
text strings within one or
more files. The sed string
substitution command is often
used to accomplish this, where
sed is passed a file name, the
string substitutions are written
to another file, and then that
file is copied over the first
file to effect the changes
desired in the original.

This approach has some inherent
problems. The command syntax is
lengthy and cumbersome, a
secondary file is created
which involves additional disk
I/O, and when that file is
copied or moved back over the
first one, permissions problems
and file ownership problems can
be created. If your umask
doesn't match the permissions of
the original file, then the
permissions of the final modified
file will be different than those
of the original. Likewise,
default ownerships and group
names are imposed on the temporary
copy, and if one is not careful,
when the temporary copy is written
back to the original file, these
can destroy the original file's
ownership and group information.

A much better way to accomplish
text substitution within a file or
group of files is to use the
"perl pie" approach, as shown here
on file foo:

perl -p -i -e 's/original text string/replacement string' foo

The above command will replace the
first instance of "original text
string" with "replacement string"
in file foo. If you want to
perform this globally within the
file, add the /g global specifier
at the back end, as follows:

perl -p -i -e 's/original text string/replacementstring/g' foo

To act on several files in the
same directory, change the file
specification as needed, by
specifying foo*, *, or whatever
you need.

Note that perl uses the exact
same syntax for the actual string
substitution portion of the command
as sed does, which makes the command
syntax easy to remember. However,
perl performs the entire operation
on the file without the use of any
secondary files needing to be
created, which eliminates the extra
disk I/O and the potential
permissions and ownership issues.

This tip generously supported by: jem@postfive.rose.hp.com

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

Unix Tip: CHANGING A PRINT QUEUE IP

2011-12-25T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3607 - December 25, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

CHANGING A PRINT QUEUE IP

To change the IP address of
a print queue in HP UX 10.20
(and maybe others), go to
/var/spool/lp/interface.
Edit the file with the same
name as the print queue and
change parameter PERIPH to
the new IP address.

For example, to change
printer_1 from 127.0.0.2 to
127.0.10.10, edit
/var/spool/lp/interface/printer_1
and change the line PERIPH=127.0.0.2 to
PERIPH=127.0.10.10.

Disable and enable printer_1,
and jobs sent to printer_1 will
go to the new IP address.

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

Unix Tip: MOVING FILES AROUND

2011-12-24T01:42:00.001-08:00

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3606 - December 24, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

MOVING FILES AROUND

Here is another way to move
files around.

Sometimes you find yourself
wanting to move a bunch of
files into a new directory
that is to be created in the
current working directory.

Rather than using a temporary
directory, or grep and variable
substitution; use a subshell:

$ ( \ls; echo dir; mkdir dir ) | xargs mv

The trick is in using a subshell
to run a number of commands
_before_ the output is piped to
xargs. This idiom is also useful
for plenty of other applications.

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

Unix Tip: GOOD TIME FOR CRON

2011-12-23T01:42:00.001-08:00

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3605 - December 23, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

GOOD TIME FOR CRON

At a US government site, most of
the maintenance cron jobs ran at
noon, because testing showed that
to be the least used time in any 24-hour
weekday. Some users were around at all
hours of the night, but everyone went to
lunch!

Tibor Pollerman

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

Unix Tip: PATHS EASIER TO READ

2011-12-22T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3604 - December 22, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

PATHS EASIER TO READ

Am I the only one who finds the

% echo $PATH

and

% echo $LD_LIBRARY_PATH

unreadable? Try this to make
for something thats much easier
to read:

echo $PATH | tr ":" "\n"

This tip generously supported by: ng@clubgeek.net

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

Unix Tip: KEEP THAT USER OUT!

2011-12-21T01:42:00.001-08:00

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3603 - December 21, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

KEEP THAT USER OUT!

Ever get into one of
those pesky admin wars
or need to keep the
developers off of your
system for a few minutes
without taking the system
to single user mode?

This nasty little script
will do the trick.

[root@foo /]# while true
> do
> kill -9 $(ps -aux |grep username | awk '{ print $2 }' )
> sleep 2
> done

This can make you the life
of the party (At work)

Don Cooley
Unix Systems/Security Admin
Wellogix Inc.
dcooley@wellogix.com

This tip generously supported by: dcooley@wellogix.com

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

Unix Tip: GETTING IPs FROM IFCONFIG

2011-12-20T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3602 - December 20, 2011

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=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

GETTING IPs FROM IFCONFIG

You can use ifconfig to lookup
IP addresses bound to your box.
If you do not want to search the
output from ifconfig, use the
following command to get just
the IP listing.

ifconfig | awk '/inet/{print $2}' | awk -F: '{print $2}'

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

Unix Tip: PING THE HOST TABLE

2011-12-19T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3601 - December 19, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

PING THE HOST TABLE

There's no need to grep and
pipe the output into awk
(you can "grep" with awk.)

awk '/^[0-9]/{print $1}' /etc/hosts |xargs -l ping -c 1 $1

This tip generously supported by: bmaclean@silverplatter.com

And another:

awk '/^[^#]/ {system("ping -c 1 "$1)}' < /etc/hosts

This tip generously supported by: maddox@xmission.com

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

Unix Tip: USES FOR AWK

2011-12-18T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3600 - December 18, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

USES FOR AWK

If you have a server
with alot of filesystems
on it (oracle/SAP
environments) then this
little awk command can
come in useful. It can
obviously be used in many
other situations also. In
this example, the file
structure is /oracle/PRD/xxxx.

awk '/PRD/{ print "umount " $3 }' /etc/vfstab | /sbin/sh

If you run it without
piping it to 'sh', then it
will show you what the command
will do. You can replace the
'umount' with whatever command you
like. It's a quick and easy though.

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

Unix Tip: PERL FIND AND REPLACE

2011-12-17T01:42:00.001-08:00

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3599 - December 17, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

PERL FIND AND REPLACE

In UNIX environment, the
following combination of perl
and find will serch for a
particular file and replace
the occurence of a particular
string with another string in
that file. This will also
work for multiple files and
directories. The find
command finds the file and
the perl script replaces
old string with the new one.

At the command prompt give
this command:

# perl -pi -e 's/<old string>/<new string>' `find . -name "<file name>"`

NB: Perl should be in the
path and the general regular
expression rules apply while
using special characters
for eg / or .

This tip generously supported by: pandpr@dh.cit.alcatel.fr

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

Unix Tip: BE ALARMED

2011-12-16T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3598 - December 16, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

BE ALARMED

Name the following script
alarm. Make it executable
and them invoke it as:

% alarm 10 "Time for tea"

After 10 seconds machine will
echo Time for Tea
and beep five times.....

---------------

#! /usr/bin/ksh
# alarm program
# displays a message at
if [ $# -ne 2 ]
then
echo "USAGE : $0 seconds message"
exit 1
fi

time=$1
mesg=$2
signal_alarm()
{
sleep $time
banner $mesg
for i in 1 2 3 4 5 6 7 8 9
do
if [ $i -eq 2 -o $i -eq 4 -o $i -eq 6 -o $i -eq 8 ]
then
sleep 1
else
tput bel
fi
done
}

case $1 in

[0-9][0-9][0-9] | [0-9] | [0-9][0-9] )signal_alarm &;;
*)echo Seconds range is from 0 to 199;;

esac

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

Unix Tip: NUMBERING A FILE

2011-12-15T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3597 - December 15, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

NUMBERING A FILE

Ever want line numbers
appended to a file. Here
is a short script.

awk '{no=no+1; printf"%d : %s", no, $0}' filename > filename.out

Another shorter but not
necessary elegant method
is:

grep -n . filename > filename.out

filename is the original file
filenmae.out is the file with
line numbers appended at the
beginning of each line

This tip generously supported by: pradeep@unixguru.zzn.com

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

Unix Tip: BACKING UP FILES

2011-12-14T01:42:00.001-08:00

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3596 - December 14, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

BACKING UP FILES

Ever needed to backup all
of your configuration files
in one fail swoop?

Using an editor create a
file:

vi configlist

Enter the full path of the
files needed to backup.

/etc/passwd
/etc/inetd.conf
/etc/hosts/allow
/etc/hosts.deny
and so on until you have a full list of files.
Save the file and quit

:wq!

Compress the files using tar:

tar cvfzT /tmp/backup.tar.gz configlist
tar: Removing leading `/` from absolute path names in the archive
etc/passwd
etc/inetd.conf

WARNING! This file contains some files that could only be read by a
limited number of users. Store it carefully so only the Administrator can
access it.

Check "man tar" on your flavor,
the "z" and "T" options are
not available on all flavors
of unix.

This tip generously supported by: darren.mallett@tradermedia.co.uk

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

Unix Tip: SNEAK THE EDUCATION IN

2011-12-13T01:42:00.001-08:00

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3595 - December 13, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

SNEAK THE EDUCATION IN

During these times of tight
budgets. It is hard to
convince the boss to pay for
a class or conference. When
being quoted for a new
system ask the vendor to
toss in some education
classes into the price of
the quote.

There are 2 benefits to this:

1) Education in most
IT organizations comes out of
a different budget so you
are saving the company money
since that you don't need to
use the funds from that pool
of money.

2) If you need to negotiate
the price of the quote or tell
the vendor you are taking it
to bid against a competitor;
educational classes are like
dessert at a restaurant. They
sometimes can toss it in for
free to keep your business.

But either way, the goal is
to get the classes on the
quote!

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

Unix Tip: MANIPULATE MULTIPLE FILES

2011-12-12T01:42:00.001-08:00

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3594 - December 12, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

MANIPULATE MULTIPLE FILES

If you have a directory with
large number of files and you
want to rename or copy or
process it, here is a simple
way to do it;

# for temp in *
> do
> echo cp $temp $temp.org >> t.txt
> done

You can change the copy command
to what ever that you need to
do. This will create a file
tmp.txt with all the files
listed in the current working
directory and insert a line
into the file tmp.txt as;

cp filename filename.org

This tip generously supported by: tyl@computer.org

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

Unix Tip: UNDO HP SECURE PASSWORD FACILITY

2011-12-11T01:42:00.001-08:00

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3593 - December 11, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

UNDO HP SECURE PASSWORD FACILITY

If you have run command
pwconv to convert to secure
password and later want to undo
it, here it how;

/etc/tsconvert -r

This only for HP Unix and no
man pages for this.

This tip generously supported by: tyl@computer.org

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

Unix Tip: COMMENT OUT MULTIPLE LINES

2011-12-10T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3592 - December 10, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

COMMENT OUT MULTIPLE LINES

Ever wanted to comment out
multiple lines of code while
writing shell
scripts in vi, but didn't want
to pound your keyboard for half
an hour doing it?

(I#Escape j.j.j.j. = carpal tunnel)

Here's the nerdy way to do it:

:.,+N-1 s/^/#/g

Where N-1 is the number of lines
minus one that you want to comment
out, and s/^/#/g is the regular
expression (the pattern between the
first two slashes is what you want
to replace, in this case the
beginning of the line, and the
pattern between the last two slashes
is what you want to replace it with).

For example, if you're a bad
coder like me and want to comment
out 500 lines of code, you would do:

:.,+499 s/^/#/g

This tip generously supported by: maddox@xmission.com

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

Unix Tip: HOW MUCH SOLARIS MEMORY?

2011-12-09T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3591 - December 9, 2011

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

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HOW MUCH SOLARIS MEMORY?

To determine the amount of main memory on Solaris:
1) /usr/platform/sun4u/sbin/prtdiag
2) wsinfo
3) '/usr/sbin/prtconf | grep -i memory'

This tip generously supported by: M.Nithyanandham@blr.spcnl.co.in

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

Unix Tip: EDITING OF LARGE FILES

2011-12-08T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3590 - December 8, 2011

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

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EDITING OF LARGE FILES

Ever failed to open a very large
file for editing in vi. Just try
this tip:

Suppose you want to make changes
in top 500 lines of a 100 line file
abc.txt.

tail +500 abc.txt > tail.txt
head -500 abc.txt > head.txt

Edit file head.txt by opening in
a vi editor.

Now append file tail.txt to
head.txt by:

cat tail.txt >> head.txt
mv head.txt > abc.txt
rm head.txt tail.txt

This tip generously supported by: akash@cadence.com

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

Unix Tip: LEAKING MEMORY?

2011-12-07T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3589 - December 7, 2011

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

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LEAKING MEMORY?

Do you want to know the list
of memory leak detecting tools:

http://www.cs.colorado.edu/homes/zorn/public_html/MallocDebug.html

This tip generously supported by: M.Nithyanandham@blr.spcnl.co.in

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

Unix Tip: TRUSS THE PID.....

2011-12-06T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3588 - December 6, 2011

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

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TRUSS THE PID.....

To check the system calls and signals
coming into and going out of a
process use /usr/bin/truss.

i.e. truss pid

This tip generously supported by: bareddy_sm@yahoo.com

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

Unix Tip: VERIFY AFTER VACATIONS

2011-12-05T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3587 - December 5, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

VERIFY AFTER VACATIONS

Be sure to check all vital systems and
processes once returning froma vacation.

Don't ignore your log files or backup
reports. You may have alot of email
from automated jobs. READ ALL OF THEM!

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

Unix Tip: VERIFY AFTER VACATIONS

2011-12-04T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3586 - December 4, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

VERIFY AFTER VACATIONS

Be sure to check all vital systems and
processes once returning froma vacation.

Don't ignore your log files or backup
reports. You may have alot of email
from automated jobs. READ ALL OF THEM!

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

Unix Tip: FIND AND EDIT IN ONE

2011-12-03T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3585 - December 3, 2011

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

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FIND AND EDIT IN ONE

Have You Ever found a need to find a file for a particular pattern and then
edit the same ??

Here is an easiest way....

At the UNIX prompt,
Just type:

vi `find . -name "*" -exec grep -l "pattern" {} \; -print`

Where "pattern" is the string to be searched.

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

Unix Tip: CARROTS ARE GOOD FOR YOU

2011-12-02T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3584 - December 2, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

CARROTS ARE GOOD FOR YOU

Most often when we try to execute a command at the shell we do
some mistakes like missing out a char or misspelling it.
Here is a easy way of correcting the mistake without having
to type the entire command again!.

In the below command "name" has been misspelled as "naem"

$ find . -naem "*.txt" -print
find: invalid predicate `-naem'

The above command would be valid if we replace "em" (in naem)
to "me"( to have name ). Use carrots to make this change

$ ^em^me^
find . -name "*.txt" -print

This technique works well with bash and csh.

This tip generously supported by: desikann@future.futsoft.com

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

Unix Tip: WHERE ARE THOSE PARENTHESES?

2011-12-01T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3583 - December 1, 2011

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

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WHERE ARE THOSE PARENTHESES?

Do you ever lose your way in multiple levels of parentheses
or braces? If you program in Perl or C, you know what I
mean. Let the vi "%" command help you. Move the cursor to
a parenthesis or brace and type %. vi will move the
cursor to the corresponding character. Hit % again and vi
will return to the original parenthesis or brace.

For extra power, issue "/{" to find the first open brace.
Hit "%" twice to find the corresponding brace and return.
Hit "n" to find the next open brace. This allows you to
zip through the file checking your program structure.

It makes you feel sorry for Windows-based editors!

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

Unix Tip: GREP TEXT NOT BINARY

2011-11-30T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3582 - November 30, 2011

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

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GREP TEXT NOT BINARY

In some directories such as /etc you have a mix of file types.
You may want to grep out a string from one of the files but
don't want to worry about the binaries, data, etc. To accomplish
this, searching only text files do this:

grep <string> `file * | egrep 'script|text' | awk -F: '{print $1}'`

This tip generously supported by: Richard.place-eds@eds.com

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

Unix Tip: GET THE HIDDEN FILES

2011-11-29T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3581 - November 29, 2011

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

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GET THE HIDDEN FILES

A safe way of grabbing all "hidden" files is to use '.??*'
rather than '.*' since this will only match 3 or more
characters. Admittedly, this will miss any hidden files
that are only a single character after the ., but it
will always miss '.' & '..', which is probably more
important...

This tip generously supported by: leopard@midwinter.com

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

Unix Tip: FINDING A STRING

2011-11-28T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3580 - November 28, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

FINDING A STRING

How to find a string somewhere on the system. Many times we are
called to search for a string, but we have no idea where it may
be lurking. Judicious use of the find and grep commands will
make you a hero with your co-workers.

# find . -type f -exec grep "string or options" /dev/null {} \;

Normally using only:
# find . -type f -exec grep "string/options" {} \;

Produces the target string, but you will have no clue as to where
it is located, making this almost as frustrating as using windoze!
Remember when grep'ing against multiple files the filename will be
listed before the match.

$ grep there *
foo:I found the target here
bar:You are there

In our find command we use /dev/null as a file to search against, since
we know the search will always fail if the string is found in "{}" there
filename is printed. To borrow from a famous quote:
"Pretty tricky sis!"

This tip generously supported by: james_b_horwath@glic.com

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

Unix Tip: RANDOM LINES FROM A FILE

2011-11-27T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3579 - November 27, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

RANDOM LINES FROM A FILE

A easy way to retrieve random lines from a text file:

perl -e '$count = 10; @line = <>; for (1..$count) { print $line[int rand @line] }'

example:
% cat /etc/passwd | perl -e '$count = 10; @line = <>; for (1..$count) { print $line[int rand @line] }'

This tip generously supported by: abend@110.net

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

Unix Tip: EXTRACT THAT LAST FIELD

2011-11-26T01:42:00.000-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3578 - November 26, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

EXTRACT THAT LAST FIELD

You can use 'cut' to extract the last field of a line if you know
how many fields there are, eg:

field=`cut -d: -f8 file`

But if you don't know the maximum number of fields or the number
of fields per line are not consistent, awk can come to the rescue.
awk has the inbuilt variable NF for the number of fields. By using
this variable we can use it to extract the last field by using:

field=`awk -F: '{print $NF}'`

or you can use calculations to retrieve any field relative to the last field.
For example to retrieve the second last field, use:

field=`awk -F: '{print $(NF-1)}'`

This tip generously supported by: peters@ginini.com.au

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

Unix Tip: FULL OF FILESYSTEM INODES

2011-11-25T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3577 - November 25, 2011

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

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FULL OF FILESYSTEM INODES

We recently had a problem where a file system had 100% inode usage.
Unfortunately there isn't an easy way to search for directories with
a lot of files in them (1 file = 1 inode). And if the files are small,
you can't rely on du to help you out.

Here is a find command that will print all the directories in the
current filesystem, with the number of files (inodes) in that directory.

find . -xdev -type d -exec /bin/echo -n {} \; -exec sh -c "ls {} | wc -l" \;

This tip generously supported by: rickb@cmhcsys.com

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

Unix Tip: FORGET THE CRONTAB MAN

2011-11-24T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3576 - November 24, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

FORGET THE CRONTAB MAN

For some reason many admins forget the field order of the
crontab file and alway reference the man pages over-and-over.
Make your life easy. Just put the field definitions in
your crontab file and comment (#) the lines out so the
crontab file ignores it.

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

Unix Tip: POWER OF BACKQUOTES

2011-11-23T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3575 - November 23, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

POWER OF BACKQUOTES

Backquotes are the most powerful things in Unix. More than one
Unix commands can be run simultaneously on the prompt.
In csh,

% find . -name "*.txt" -print

gives the path & names of the files with extension ".txt" in
current directory and its subdirectories. If you want to open
these files in vi together then

% vi `find . -name "*.txt" -print`

Similarly,

% find . -name "*.txt" -print
<listing of all txt files. in current directory/sub-dirs>
% vi `!!`

this will open all those files in vi listed by find command.

This tip generously supported by: dhruvm@duettech.com

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

Unix Tip: PING THE HOST TABLE

2011-11-22T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3574 - November 22, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

PING THE HOST TABLE

Here is a quick way to ping all the hosts in your host table.
NOTE: Just make sure that there are no blank lines in it, and
verify the ping command on your system exist after one ping. Your
mileage may differ slightly.

$ grep -v "#" /etc/hosts | awk '{print $1}' | while read host
> do
> ping -c 1 $host
> done

Or script it:

#!/bin/sh
grep -v "#" /etc/hosts | awk '{print $1}' | while read host
do
ping -c 1 $host
done

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

Unix Tip: A SHAMELESS PLUG

2011-11-21T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3573 - November 21, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

A SHAMELESS PLUG

The Best Tip I can give you right now is to pick up a copy of
UNIX HINTS AND HACKS By the Creator of UGU.

It is available at Barnes & Nobles, Borders, and Technical book stores.

Some of the past tips from UGU can also be seen in the book.

http://www.amazon.com/exec/obidos/ASIN/0789719274/unixguruuniverse

Here are what some UGU'ers are saying about the book:
-----------------------------------------------------
mikec@sficorp.com from Green Bay, WI , August 21, 1999
FANTASTIC - FIVE STARS *****
This is a great book for those looking for quick solutions
to common real work scenarios. If you are responsible for
Unix (yes including Linux) systems this is one book you have
to have. For coding solutions the book usually shows both shell
script and perl examples for the same problem

jbaduria@hotmail.com from San Mateo, CA, USA , August 19, 1999
GREAT BOOK!! - FIVE STARS *****
Finally a book that deals with the real things that most UNIX
system administrators face. It saves you the trouble of finding
out things only after you face it. You could save yourself
a lot of time solving problems that could have been avoided
by reading this book. With the price nothing beats it. Not even
those $30+ books.

link2000@n-link.com from Tx, Usa , June 25, 1999
GREAT BOOK - FIVE STARS *****
This is a great book. It has many tricks that are geared toward real
world experience that are not covered in any other book I have seen.
I especially liked the section geared toward getting your first
job as an system admin. It is one book worth buying. For all kinds
of information for less than 15 dollars how could you go wrong.

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

Unix Tip: REPETITIVE TASKS WITH XARGS

2011-11-20T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3572 - November 20, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

REPETITIVE TASKS WITH XARGS

Save yourself a lot of typing when you have to perform repetitive
commands on a list of files. Put the list of files in a text file
with one file per line ie: find . -name version.C > filename
Then have xargs build a command line for each file in the list as
follows:

cat filename |xargs -n 1 cp anotherfile

This will copy anotherfile over all the files listed in
filename one at a time until the end of filename is reached.

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

Unix Tip: Suppose we want to check whether the web server is running or

2011-11-19T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3571 - November 19, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

Suppose we want to check whether the web server is running or
not, but we don't have any browsers ( lynx, IE, Netscape ...),
then there is a simple way of doing that. Just telnet to that
machine on the http port ( port no 80 in general).

% telnet <ip addr> <port no>

And then, say "get /" (without quotes). If the webserver is running,
it displays the HTML script of the homepage or basic info and closes the
connection to the remote host.

% telnet yahoo.com 80
Trying 204.71.200.245...
Connected to yahoo.com.
Escape character is '^]'.
get /
HTTP/1.0 302 RD
Location: http://www.yahoo.com/

Connection closed by foreign host.

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

Unix Tip: CTRL-D ANOTHER USE

2011-11-18T01:42:00.000-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3570 - November 18, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

CTRL-D ANOTHER USE

Many Unix Admins use the C shell as their interactive shell.
An often used feature of Csh is file completion - initiated
with 'set filec'. It allows the Csh user to type in partial
file names, and then press escape to get them completed where
possible. A little known side effect of this is that
Control-D (^D) will now generate file listings in the middle of
command lines.

Example 1: (where @ is a space)
host > @^D
Lists the current directory

Example 2:
host >ln -s /usr/^D
Lists the /usr directory

host >tar cvf /dev/nrtape /usr/m^D
Lists all m* files in the /usr directory

In each case, after the listing, you get a new command line and are
placed at the last point of edit.

Very handy if you you know what you wanted to do but forgot what you
wanted to do it with!

This tip generously supported by: mikal.dunn@halliburton.com

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

Unix Tip: HIDE THOSE FILES

2011-11-17T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3569 - November 17, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

HIDE THOSE FILES

If you want to have some hidden directories on your server (warez etc.)
then make a directory with permission 111.

% chmod 111 foo/

All the contents will become hidden:

% cd foo
% ls -al
Cannot access directory .: Permission denied

The directory will have to opened back up (755) in order to see or access
the files or the directory. To remove the directory and its contents, it
will also need to have the permissions opened.

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

Unix Tip: TCSH AND RMSTAR

2011-11-16T01:42:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3568 - November 16, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

TCSH AND RMSTAR

tcsh has a nice built in variable:
set rmstar

Whenever you type the command:

% rm *

The shell will ask you to confirm, this prevents you from deleting
all your files accidentally.

Add "set rmstar" in you .cshrc file for your own benefit.

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

Unix Tip: PERFORMANCE OF CROND TASKS

2011-11-15T01:42:00.000-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3567 - November 15, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

PERFORMANCE OF CROND TASKS

A good tip for getting better performance in crond tasks
is choosing a better time for launching them.

If the process that we want to launch needs few time,
but can overload the system easily, you can launch
the task in hours that the work is busy and -and HERE
is the tip- in strange minutes. That's why lots of
people launch their crons at midnight, but
nobody uses to do it at 00:13, in example.

That tip can obtain his best in hourly-launched
tasks. If that kind of tasks are launched all at
the same time, the system will overload without
any use. You can delay that kind of tasks (one
at 13th minute, other at 17th minute,other at
27th minute...) and obtain better performance
without work. That will avoid overloading caused
by launching several tasks at the same time.

The best is that administration tasks do
not overlap, but this is not always possible.
If you can do it, it's better you do it.

Using nice is also a good idea.

But the best is making a log of the uptime during
a week. You can be surprise, because all the staff
of a department of a firm use to do the coffee-break
at the same time; it's the perfect time for making
some administrative tasks. :-)
But do not clear the forbidden extensions -the famous
find /home -name core -exec \{\} \; and other stuff
like tmps, ~s and so on- of the system
at work time, or you will have a queue of staff people
very, very angry knocking at your door.

This tip generously supported by: irbis@activanet.es

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

Unix Tip: SHELL SCRIPTING A SQLPLUS SCRIPT

2011-11-14T01:42:00.000-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3566 - November 14, 2011

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

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SHELL SCRIPTING A SQLPLUS SCRIPT

Here is a tip on how to run sqlplus scripts within a shell script.
It is an example of how to pass database values into shell variables
and to make shell scripts more dynamic. This maybe elementary to some
folks but hope it helps others.....Here is the syntax:

#!/bin/sh
dummyvar=`sqlplus -s username/password <<end
set pagesize 0 feedback off ver off heading off echo off
select sysdate from dual;
exit;
end`
echo "system date is " $dummyvar

Unix Tip: I SEE YOU WITH FUSER

2011-11-13T01:42:00.000-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3565 - November 13, 2011

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

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I SEE YOU WITH FUSER

In System V, you can use the following command to see who is accessing
a particular file system:

fuser <file system>

For example, to see who is accessing the /cdrom directory:

fuser /cdrom

This command is useful if you wish to unmount a file system but the system
is unable to do so because it is being used.

This tip generously supported by: anthony-leong@usa.net

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

Unix Tip: GLOBAL SYSTEM PATH SETTINGS

2011-11-12T01:42:00.000-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3564 - November 12, 2011

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

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GLOBAL SYSTEM PATH SETTINGS

Cross-Platform System Administration Tip

If you want to set a system path that will apply to all users,
regardless of which shell they use, edit the following file:

For Solaris: /etc/default/login
For HP-UX: /etc/PATH
For AIX: /etc/environment

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

Unix Tip: KILLING ALL USER PROCESSES

2011-11-11T01:42:00.000-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3563 - November 11, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

KILLING ALL USER PROCESSES

The common method for killing all of a users processes
usually involves grepping the users name from 'ps', then
using awk to get the process id's and submitting them
to 'kill -9'.

Sys V
ex: kill -9 $(ps -fuusername | awk '{ print $2 }' )

BSDish
ex: kill -9 $(ps -aux |grep username | awk '{ print $2 }' )

The problems with doing this way are that it is slow, and
more importantly, it doesn't always kill all of the processes
on the first try.

There is a way to do this that always kills all of the users
processes the first time, and is very fast:

su - username -c 'kill -9 -1'

This tip generously supported by: jkstill@teleport.com

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

Unix Tip: NFS HANG FIX ON HP-UX

2011-11-10T01:42:00.000-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3562 - November 10, 2011

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

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NFS HANG FIX ON HP-UX

In an NFS environment (Hp-UX based), sometimes no user is
able to log-in when home directories are mounted using automounter).
As user validation occurs, the user .profile is executed but no shell
prompt appears unless the user presses CTRL-C.

The Solution to this is to kill the portmap & inetd and restart
the two daemons. The problem will then be sorted out.

This tip generously supported by: sgogia@hss.hns.com

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

Unix Tip: REGEXP MATCHING IN AWK

2011-11-09T01:42:00.000-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3561 - November 9, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

REGEXP MATCHING IN AWK

If you ever find yourself typing "command | grep pattern | awk '{print $3}'
you can shorten this by using the regexp matching in awk, like this:

command | awk '/pattern/{print $3}'

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

Unix Tip: Public Relations

2011-11-08T01:42:00.000-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3560 - November 8, 2011

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

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Public Relations

One of the best things an admin can do
is to have good public relations with
the user community.

Don't just be there when problems arise.
Go out to the user community when things are
working. High visibility is the key.

If the users see you around and there are no
problems they will believe that you care to
take the time for them.

Try not to let the users always go come to you.

Go to those users that you never here from
The perfect users, the ones that leave you
alone. Often the don't have an understanding
of what you can do for them.

I know many will say, "I don't have time!"
Just a calm walk through a department is
really all it takes, sometimes you never
have to stop.

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

Unix Tip: CLEANUP AT LOGOUT

2011-11-07T01:43:00.001-08:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3559 - November 7, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

CLEANUP AT LOGOUT

The following c-shell .logout script will clear your Netscape
cache. No action will be taken if Netscape is current running.

------------------- CUT HERE ------------------------------
#!/bin/csh

if !( `ps -eu $USER | grep netscape | grep -v grep | sed -e 's/^ *//' -e 's/ .*//'` ) then
echo
echo "Clearing Netscape cache..."
\rm -rf ~/.netscape/cache/*
endif

echo
echo "Exiting..."

------------------- CUT HERE ------------------------------
This tip generously supported by: rb237@phy.cam.ac.uk

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

Unix Tip: SPEED UP INTERACTION TIME

2011-11-06T01:43:00.001-07:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3558 - November 6, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

SPEED UP INTERACTION TIME

One way to speed up the interaction time of
a shell (that does not hash its commands)
that you may overlook is to modify your path.
The order of the directories in your path
should rely on the number of commands you use
most. So /usr/bin or /bin would probably be first.
Very large directorys that are mounted over
the network should be later in the list. If
there are some directories in your path you only
use for one or two commands consider making an
alias or shell script (if your shell doesn't
support aliases) which calls the program with its
full path name.

Watch out when sourcing files, especially when
your root. It could modify your path and make
you run something detrimental to your system.
Getting into the habit of using full pathnames
is the key here.

This tip generously supported by: kevin@ti.com

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

Unix Tip: AWK QUICK COLUMNS

2011-11-05T01:43:00.001-07:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3557 - November 5, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

AWK QUICK COLUMNS

Most of the time when you use awk from the command line,
you're doing something simple like this:

ps -ef | grep netscape | awk '{print $2}'

To save typing, use this script when you only want to
use awk to print out one or more columns:

------------------- CUT HERE ---------------------------
#!/bin/ksh
# awkc - print out one or more columns

p=\$$( echo $1 | sed 's/,/,\$/g' )
shift
eval "awk '{ print $p }'" $*

# eof
------------------- CUT HERE ---------------------------

Now you can do things like:
ps -ef | awkc 2,1
or
awkc 1,2,3 /var/adm/messages*

This tip generously supported by: kbeer@dbna.com

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

Unix Tip: MONITORING ROOT IN THE PASSWORD FILE

2011-11-04T01:43:00.001-07:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3556 - November 4, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

MONITORING ROOT IN THE PASSWORD FILE

One of the popularly known method of breaking into a Unix host
is by inserting a uid value 0 in the /etc/passwd file which could
be done in many ways including backdoors for later accesses .

The script below displays warning messages on the console if
such changes a detacted. Simply place the script in the crontab
and run as frequent as you wish.

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

for id in `awk 'FS=":" {if(($3 == 0 && $1 != "root" )) print $1}' /etc/passwd`
do
cat << the_end >/dev/console

+----------------------------------------------------------------
|
| `date "+Detacted On Date :%D Time :%r"`
| Break-in ALERT! Login ID `echo ${id}` has uid 0
|
+----------------------------------------------------------------

the_end
done
------------------------------CUT HERE-----------------------------------------

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

Unix Tip: CREATE YOUR OWN GROUP ALIASES

2011-11-03T01:43:00.001-07:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3555 - November 3, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

CREATE YOUR OWN GROUP ALIASES

If you want to create an alias for a group of people with
similar interests, on your workstation (Say a SUN
workstation), then include the following line at the end
of the file /etc/aliases and run the command /bin/newaliases

unixtips: bhavin@foobar.com, atulk@foobar.com, virajpikle@mail.com

Now, an e-mail sent to
alias_name@workstation_name.foobar.com
will be bounced to the addresses listed above in the
/etc/aliases file.

In other words, if my workstation name is "soorya",
an e-mail sent to
unixtips@soorya.foobar.com
will be bounced to
bhavin@foobar.com,
atulk@foobar.com, and
virajpikle@mail.com

This tip generously supported by: bhavin@informix.com

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

Unix Tip: KILL X

2011-11-02T01:43:00.001-07:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3554 - November 2, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

KILL X

Quick way to close your X login session (for SysV)

for PID in `ps -u$USER | grep "fv[wm]" | awk '{print $1}'`; do kill -9 $PID; done

Or throw it into a shell script:

--- cut here ---
#!/bin/sh

for PID in `ps -u$USER | grep "fv[wm]" | awk '{print $1}'`; do
kill -9 -$PID
done
--- cut here ---

(the [] conceal the grep from ps, which would mean it would
kill itself before doing anything useful. as written up,
it looks for fvwm's process, which is the window manager I
use; rewrite it as needed i.e. for Motif - mwm,
Open Look - olwm, etc.)

Write this up in a shell script contained in your $PATH
or alias it and you're cooking with gas.

This tip generously supported by: klaus@imprint.uwaterloo.ca

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

Unix Tip: ALTERNATIVE TO CP

2011-11-01T01:43:00.001-07:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3553 - November 1, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

ALTERNATIVE TO CP

Define the following alias:

tar cvf - . | ( cd \!* ; tar xvf - )

or as an alias:

alias cpbytar 'tar cvf - . | ( cd \!* ; tar xvf - )'
(The alias definition above is for CSH)

To do a recursive copy of a directory to another location,
preserving the PERMISSIONS and OWNERSHIP of the files.
"cd" to the source location and invoke the following alias

cpbytar <destination_directory>

This tip generously supported by: bhavin@informix.com

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

Unix Tip: -------- REMOVE THE DASHES

2011-10-31T01:43:00.001-07:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3552 - October 31, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

-------- REMOVE THE DASHES

Have you ever accidentally created a file beginning with '-'?
It happens often by mistake and from the first look it seems
like you can't delete the file (rm thinks the initial - is an
option, and doesn't recognize the file).

The simple, quick way around this is the -- option to rm.
Say you had the file ---hey in the current directory:

$ ls ---hey

/bin/ls: unrecognized option `---hey'
Try `/bin/ls --help' for more information.

$ ls|grep hey
---hey

$ rm ---hey
rm: unrecognized option `---hey'

Try `rm --help' for more information.
$ rm -- ---hey

( ls also has an -- option: )

$ ls -- ---hey
/bin/ls: ---hey: No such file or directory
$

This tip generously supported by: root@analog.org

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

Unix Tip: SEPARATE SHELL COMMAND HISTORY FILES

2011-10-30T01:43:00.001-07:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3551 - October 30, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

SEPARATE SHELL COMMAND HISTORY FILES

In any X based desktop when the number of pseudo terminal
windows are more then one, the common shell history
file (KSH) becomes a nuisance. Here is a way to have
separate, safe and limited shell command history files.

Put the following code in your shell RC file.

--------------------------------CODE START------------------------------------
# Form a unique name for the shell history file using the tty output and
# set the shell variable HISTFILE to point to that
# This solves the problem of mutiple shells using the same history file
# and causing the confusion....
histf=`tty | awk 'BEGIN {FS="/"; nm=".shist_"} { for (i=1; i<=NF; i++) nm = nm
$i;} END { print nm;} '`
export HISTFILE=$histf
\rm -f $histf
echo History file is $histf...
--------------------------------CODE END------------------------------------

This tip generously supported by: atulk@informix.com

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

Unix Tip: SHARING STDIN/STDOUT ON 2 TERMINALS

2011-10-29T01:43:00.001-07:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3550 - October 29, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

SHARING STDIN/STDOUT ON 2 TERMINALS

Ever wanted the standard input and standard output
to be shared on two terminals?

Try the following short script,

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

[ $# -lt 2 ] && echo "Usage: $0 program ttytodupon" && exit 2
mytty=`tty`
prog=$1
othertty=$2
sh -c "$prog|tee -a $mytty" 1>$othertty 2>&1 0>$othertty

------------------- CUT HERE -------------------------
This tip generously supported by: ian@kiwiplan.co.nz

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

Unix Tip: SET REMOTE DISPLAY QUICKLY

2011-10-28T01:43:00.001-07:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3549 - October 28, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

SET REMOTE DISPLAY QUICKLY

If the environment and home directory structure
are centralized, then build a set of alias tables
for setting the display for all remote machines
that may get logged into remotely or administrate
remotely. In the long run it will save time.

alias 'setwad setenv DISPLAY wad:0'
alias 'setspot setenv DISPLAY spot:0'
alias 'settrash setenv DISPLAY trash:0'

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

Unix Tip: MULTI-SYSADMIN MONITORING

2011-10-27T01:43:00.001-07:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3548 - October 27, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

MULTI-SYSADMIN MONITORING

To can see what someone logged in as root is running,
if root's shell uses .sh_history ( ksh, for example ) do:

# tail -f /.sh_history

This is good in multi-Sysadm environments when you want to
get an idea of what another admin is doing to fix something.

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

Unix Tip: ABBREVIATE IN VI

2011-10-26T01:43:00.001-07:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3547 - October 26, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

ABBREVIATE IN VI

Using .exrc file

Abbreviate in vi...
As well as using map in your .exrc file, you can use the command:

ab
For example:
ab xmas Christmas

So whenever you type xmas - Christmas will be displayed.
Handy for writing the /etc/motd file (maint - maintenance etc).

You can also use the standard set commands - for example:
set number (handy for programmers)
set redraw
set warn (flashes screen instead of using the bell)

This tip generously supported by: mbatchelor@enterprise.net

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

Unix Tip: BACKUP CRITICAL SYSTEM FILES

2011-10-25T01:43:00.001-07:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3546 - October 25, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

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.

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

Unix Tip: QUICK UNALIAS

2011-10-24T01:43:00.001-07:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3545 - October 24, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

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
==========================================================================

Unix Tip: A REFRESHING X

2011-10-23T01:43:00.001-07:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3544 - October 23, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

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
==========================================================================

Unix Tip: GENERATE RANGES OF NUMBERS

2011-10-22T01:43:00.001-07:00

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3543 - October 22, 2011

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

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

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
==========================================================================