I am using bash shell; my requirement is to run a long command.

Now I have split this long command into a number of shell variables.
Some of these shell variables contain special character ':’

At the end, when the intended long command is executed as a series of small shell variables the ':' is interpreted by the bash shell.

How can I prevent bash from not interpreting ':' ?

Can you tell us what the commands the variables are being used in.....this can have a large bearing on how the character is interpreted by the shell.

export IFS="^"
LibsDir=$YJHOME/LLib
YJLIB=$YJHOME/YjAge/YjAge.jar:$LibsDir/classes12.zip
REQJBLIB=$LibsDir/jdsserver.jar:$LibsDir/beandt.jar:$LibsDir/dx.jar:$LibsDir/sunrsasign.jar
EXTRAJBLIB=$LibsDir/i18n.jar:$LibsDir/javaplugin.jar:$LibsDir/javaplugin_l10n.jar:$LibsDir/rt.jar
JDEVELOPLIB=$LibsDir/jndi.jar:$LibsDir/jta.jar:$LibsDir/nls_charset12.jar:$LibsDir/nls_charset11.jar:$LibsDir/classes111.jar
YJCLASSPATH=$YJLIB:$REQJBLIB:$EXTRAJBLIB:$JDEVELOPLIB:$CLASSPATH
RPOL=-Djava.security.policy=jar:file:$YJHOME/YjAge/YjAge.jar!/rmi.policy
java -classpath $YJCLASSPATH -Djava.security.manager $RPOL com.yj.age.AgeBody &
==========================================
After I have added export IFS="^", in YJCLASSPATH I get an space ' ' between the concatination of variables

Okay. So you have lots of lib locations and you are trying to set these all as variables within your script...so that you can define the YJCLASSPATH for the java command at the end.

What is the error you are getting.....and can you put in some echos after certain points to see what the variables have been assigned with....particularly YJCLASSPATH and RPOL. let me know what you arrive at.

File /tmp/4.sh has below entry
export IFS=^
echo ++++++++++++++++++++++++++++++++++++
export MYJAR="$YJHOME"/Yj/YjAge.jar
export XERCESJAR="$YJHOME"/LinuxLib/sax.jar
export CLASSPATH="$MYJAR":"$XERCESJAR"
echo $CLASSPATH
echo ---------------------------------------

file: 1 has this entry
/tmp/4.sh


Now I exucute using
sh ~/1

YJHOME is set to
/tmp

I get following result:
++++++++++++++++++++++++++++++++++++
/tmp/Yj/YjAge.jar :/tmp/LinuxLib/sax.jar
---------------------------------------

As you can see I get this space between last jar for the first variable value and the begining of the next variable value

Okay...makes sense (your explanation does - the problem doesn't).

Can you add a couple of more echoes...one for
echo $MYJAR
$XERCESJAR

Also I'm assuming you've checked that there is no whitespace at the end of the variable definitions? i.e a space after the last character of this line:
export MYJAR="$YJHOME"/Yj/YjAge.jar

Because it is a variable it's effectively just a string until it is used...so spaces will count and be applied later on.

Using vi - you can use :set list

This will show you any white space at the end of the line before the eol character ($)

Try these things and let me know again.

I think I found the problem

I had edited this original file from windows 2000 machine to Linux machine using default ftp protocol. This comes with IE browser.

Later I had given chmod +x on 4.sh file.

In such a case when i execute file 4, an additional space appears while appending variable values.

Now I have converted this file from dos type to UNIX type using dos2unix utility, this has resulted in making additional space to disappear

I appreciate your effort.