bash scripting newbie

Posted on 2013-01-30
Last Modified: 2013-02-21
hi guys

I am new to bash shell scripting and have a few questions. I am from a java background.

Below is my file which invokes the customer.jar
1.  I want to modify my file so i do
$ vi
but it does not allow me to modify(it is read only), any idea why?
How can i make it editable?


export JAVA_HOME=/javaProj/jdk/1.6.0_22   
export PATH=$JAVA_HOME/bin:$PATH:$LD_LIBRARY_PATH   #  I am not sure what is $PATH:$LD_LIBRARY_PATH , any idea
export CLASSPATH=$CLASSPATH:$ROOT     #  I am not sure what is $CLASSPATH, any idea
export ROOT=/project/customer/customerAutomated

 touch $ROOT/customer.log   # does touch means it creates a file?
chmod 0777 $ROOT/customer.log



emailSubject="ERROR:- customer Status on `date`"


echo " " ; echo "BEGIN TIME = `date`"

cd $ROOT

java -Dicg.env=prod  -jar $ROOT/customer.jar 123    # any idea what this means 'java -Dicg.env=prod'
sleep 2      # this makes the program sleep for 2 seconds, right ?

echo "Checking Logs..."
if ( grep "Problem occurred" $logAutos );
        echo "Alert: Problem occurred while updating customertables..."        
        echo "END TIME = `date`"
        exit 1

echo "END TIME = `date`"
exit 0

Open in new window

Any help will be greatly appreciated
Question by:royjayd
  • 4
  • 2
  • 2
  • +1
LVL 16

Assisted Solution

choward16980 earned 50 total points
ID: 38837516
Push I to enable insert mode

push esc to exit insert mode

type :wq to write and quit.
LVL 26

Assisted Solution

pony10us earned 225 total points
ID: 38837523
What are the permissions on the file?  

ls -l

Please post the results.

Also, when in the file using vi you move the cursor to where you want to edit it and press the insert key to be able to edit. When complete you press the Esc key twice and the enter a colon and a "w" without the quotes to save the file.

Author Comment

ID: 38837553
thanks , pressing the insert key works
Courses: Start Training Online With Pros, Today

Brush up on the basics or master the advanced techniques required to earn essential industry certifications, with Courses. Enroll in a course and start learning today. Training topics range from Android App Dev to the Xen Virtualization Platform.


Author Comment

ID: 38837556
can you please help me with the questions i posted with in the script?

LVL 84

Assisted Solution

ozo earned 225 total points
ID: 38837559
What are the permissions on the file?
ls -l
shows that you do not have write permission, and that you are the owner of the file, you can
chmod u+w
If you are not the owner, then you may have to ask the owner to grant you permission.

Author Comment

ID: 38837574
ls -l

-rwxrwxrwx 1 customerproj customerproj 1745 Jan 30 18:07
LVL 26

Accepted Solution

pony10us earned 225 total points
ID: 38837580
Line 4:     I am not sure what is $PATH:$LD_LIBRARY_PATH , any idea

You can temporarily substitute a different library for this particular execution. In Linux, the environment variable LD_LIBRARY_PATH is a colon-separated set of directories where libraries should be searched for first, before the standard set of directories; this is useful when debugging a new library or using a nonstandard library for special purposes. The environment variable LD_PRELOAD lists shared libraries with functions that override the standard set, just as /etc/ does. These are implemented by the loader /lib/ I should note that, while LD_LIBRARY_PATH works on many Unix-like systems, it doesn't work on all; for example, this functionality is available on HP-UX but as the environment variable SHLIB_PATH, and on AIX this functionality is through the variable LIBPATH (with the same syntax, a colon-separated list).

LD_LIBRARY_PATH is handy for development and testing, but shouldn't be modified by an installation process for normal use by normal users; see ``Why LD_LIBRARY_PATH is Bad'' at for an explanation of why. But it's still useful for development or testing, and for working around problems that can't be worked around otherwise. If you don't want to set the LD_LIBRARY_PATH environment variable, on Linux you can even invoke the program loader directly and pass it arguments. For example, the following will use the given PATH instead of the content of the environment variable LD_LIBRARY_PATH, and run the given executable:   /lib/ --library-path PATH EXECUTABLE
Just executing without arguments will give you more help on using this, but again, don't use this for normal use - these are all intended for debugging.

Line 5:        I am not sure what is $CLASSPATH, any idea

Line 8:        does touch means it creates a file?

Has much more capability than simply creating a file:

Line 23:       any idea what this means 'java -Dicg.env=prod'

Truthfully I don't know java that well.

Line 24:        this makes the program sleep for 2 seconds, right

LVL 84

Assisted Solution

ozo earned 225 total points
ID: 38837624
man java
java(1)                                                                                                                                                  java(1)

       java - Java application launcher

       java [ options ] class [ argument...  ]

       java [ options ] -jar file.jar
            [ argument...  ]
       The launcher has a set of standard options that are supported on the current runtime environment and will be supported in future releases.  In  addition,
       the current impletmentations of the virtual machines support a set of non-standard options that are subject to change in future releases.

   Standard Options
              Sets a system property value.

Author Comment

ID: 38839693
thanks guys

>> -Dproperty=value
              Sets a system property value.

Can you tell me where i can find it ? where can i see my system properties?
Can i do a search on my system properties


Featured Post

Gigs: Get Your Project Delivered by an Expert

Select from freelancers specializing in everything from database administration to programming, who have proven themselves as experts in their field. Hire the best, collaborate easily, pay securely and get projects done right.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

The following is a collection of cases for strange behaviour when using advanced techniques in DOS batch files. You should have some basic experience in batch "programming", as I'm assuming some knowledge and not further explain the basics. For some…
Utilizing an array to gracefully append to a list of EmailAddresses
Learn several ways to interact with files and get file information from the bash shell. ls lists the contents of a directory: Using the -a flag displays hidden files: Using the -l flag formats the output in a long list: The file command gives us mor…
Sending a Secure fax is easy with eFax Corporate ( First, just open a new email message. In the To field, type your recipient's fax number You can even send a secure international fax — just include t…

815 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

9 Experts available now in Live!

Get 1:1 Help Now