Thursday, May 28, 2009

Be Careful What You Wish For

Sometimes we should be careful on what we wish for. Yeah, I am now trapping in this situation. Last year, I consulted my counselor and said to him about my interest on out-of-town or overseas project. My assignment always in the Jakarta since joined this company and client near the head-quarter. On the other hand, friends from my batch have opportunity to involve in out-of-town project or be assigned to the client which is far from the head-quarter. Different traffic jam, different allowance.
I am now a SAP-BASIS consultant. If you ask me about my position, whether I like it so I won’t hesitate answering your question “NO”. I never want to be a technical consultant and I know my capability and what I can do. I prefer involve in the project where I can understand the client’s business process and how to make the best decision to improve their production, their performance and reduce the production cost. That the reason why I love so much my last project. It was a strategic-related project. My client wanted to find the potential distributor for their product in Indonesia, distributor who know how to import a short-age product and have experience in its distribution. It was not an easy task but I love it so much although I did not get allowance.
That project also inspired me to pursue my master degree in Industrial Management and I plan to take it next year through Erasmus-Mundus’ program. But I have to prepare all the required documents such as TOEFL and GMAT certificate. And it is the big problem for me now because I just received confirmation from my HR representative that I will be assigned in Kuala Lumpur for 7 months (July 2009 – January 2010).
Arrrgh, this is suck. How can I prepare my TOEFL and GMAT certification if I be there? Maybe you will say, I can prepare myself there but GMAT is something new for me and I plan to take the course before I ready for the certification and I have to take the both certification this year because the application deadline for the reception of application is on January 2010.
What should I do? Should I reject the assignment? Or should I wait 1 more year to apply the master degree. Please show me the way out.

Monday, March 02, 2009

UNIX Crontab

Cron is used to execute tasks as background job at the specific time in UNIX system. Crontab (Cron Table) is a file which contains the schedule of cron entries to be run at specified times.

1. Crontab Restriction
You can execute crontab if your name appears in the file /usr/lib/cron/cron.allow. If that file does not exist, you can use crontab if your name does not appear in the file /usr/lib/cron/cron.deny. If only cron.deny exists and is empty, all users can use crontab. If neither file exists, only the root user can use crontab. The allow/deny files consist of one user name per line

2. Crontab Commands
export EDITOR=vi to specify a editor to open crontab file.

crontab -e Edit your crontab file, or create one if it doesn't already exist.
crontab -l Display your crontab file.
crontab -r Remove your crontab file.
crontab -v Display the last time you edited your crontab file. (This option is only available on a few systems).

3. Crontab File
A crontab file has five fields for specifying day , date and time followed by the command to be run at that interval



* in the value field above means all legal values as in braces for that column.
The value column can have a * or a list of elements separated by commas. An element is either a number in the ranges shown above or two numbers in the range separated by a hyphen (meaning an inclusive range).

4. Crontab Example
A line in crontab file like below removes the tmp files from /home/someuser/tmp each day at 6:30 PM.

30 18 * * * rm /home/someuser/tmp/*


Changing the parameter values as below will cause this command to run at different time schedule below :



If you inadvertently enter the crontab command with no argument(s), do not attempt to get out with Control-d. This removes all entries in your crontab file. Instead, exit with Control-c.

5. Crontab Environment
cron invokes the command from the user's HOME directory with the shell, (/usr/bin/sh).
cron supplies a default environment for every shell, defining:
HOME=user's-home-directory
LOGNAME=user's-login-id
PATH=/usr/bin:/usr/sbin:.
SHELL=/usr/bin/sh

Users who desire to have their .profile executed must explicitly do so in the crontab entry or in a script called by the entry

6. Disable Mail
By default cron jobs sends a email to the user account executing the cronjob. If this is not needed put the following command At the end of the cron job line .

>/dev/null 2>&1

7. Generate log file
To collect the cron execution execution log in a file :

30 18 * * * rm /home/someuser/tmp/* > /home/someuser/cronlogs/clean_tmp_dir.log