Unix and Linux Tips

Rabu, 21 Maret 2012

Unix Tip: WHO SENT ME MAIL

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3329 - March 21, 2012

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

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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 Guru Universe - www.ugu.com - tips@ugu.com - Copyright 1994-2001
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Selasa, 20 Maret 2012

Unix Tip: STRINGS - OLD BUT A GOODIE

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3328 - March 20, 2012

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

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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

Unix Guru Universe - www.ugu.com - tips@ugu.com - Copyright 1994-2001
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Senin, 19 Maret 2012

Unix Tip: RUN DAILY WITH AT

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3327 - March 19, 2012

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

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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 ##################

Unix Guru Universe - www.ugu.com - tips@ugu.com - Copyright 1994-2001
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Minggu, 18 Maret 2012

Unix Tip: FIND THOSE HIDDEN FILES

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3326 - March 18, 2012

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

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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}'

Unix Guru Universe - www.ugu.com - tips@ugu.com - Copyright 1994-2001
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Sabtu, 17 Maret 2012

Unix Tip: RUN ON LAST SUNDAY

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3325 - March 17, 2012

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

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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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Jumat, 16 Maret 2012

Unix Tip: SIMPLE MASK OVERLOOKED

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3324 - March 16, 2012

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

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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 Guru Universe - www.ugu.com - tips@ugu.com - Copyright 1994-2001
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Kamis, 15 Maret 2012

Unix Tip: AUTO WORD COMPLETION

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UNIX GURU UNIVERSE
UNIX HOT TIP

Unix Tip 3323 - March 15, 2012

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

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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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