Variable Assignment

Shell Programming and Scripting
1

Hi

I am facing a problem.

export local_folder=/opt/app/
cd /opt/app/abc/
abcversion="abc*" (abcga5 is inside /opt/app/abc/)
echo $abcversion (it echoes the correct version as abcga5 )

Now when I reuse the value of abcversion for a below path:

export ABC_HOME=/opt/app/abc/$abcversion/

echo "$ABC_HOME"

It prints

/opt/app/abc/abc*/

How can i get the actual value of abcversion in another variable assignment?

I tried searching the net and various tweaks but didnt work.

Thanks

2

When you assign

abcversion="abc*"

then $abcversion will contain just "abc*". It will not be set to "abcga5" because the quotes prevent globbing.
In the next line you do:

 echo $abcversion

which is expanded by the shell to
echo abc* and only then the abc* is expanded to abcga5.

If you do want the variable "abcversion" have the value of abcga5 you should omit the quotes in the assignment:

abcversion=abc*
3

I tried removing the quotes and here are the results:

export local_folder=/opt/app/
cd /opt/app/abc/
abcversion=abc* (abcga5 is inside /opt/app/abc/)
echo $abcversion (it echoes the correct version as abcga5 )

export ABC_HOME=/opt/app/abc/$abcversion/

echo "$ABC_HOME"

/opt/app/abc/abc*/

but I need this:

/opt/app/abc/abcga5
4

The double quotes prevent wildcard expansion, but not in the assignment ( var=pattern* is the same as var="pattern*" ),

but they do make a difference when used with the echo statement. To get the wildcard * to match, they should be left out:

echo $ABC_HOME

However, if there are multiple matches then you would get this:

echo $ABC_HOME
/opt/app/abc/abcga5 /opt/app/abc/abcga6 /opt/app/abc/abcga7
5

Hi

Its still not working. i removed quotes from everything:

See below:

cd /opt/app/abc/
abcversion=abc* (abcga5 is inside /opt/app/abc/)
echo $abcversion

echoresult:

abcga5

export ABC_HOME=/opt/app/abc/$abcversion/

echo $ABC_HOME

echoresult:

/opt/app/abc/abc*/
6

Remove the trailing /
Otherwise only matching directories are displayed.

7

Scrutinizer is right when he says: "the assignment ( var=pattern* is the same as var="pattern*" )". It can be tested by adding quotes around the argument of echo:

abcversion=abc*
echo "$abcversion"

abc*

To activate wildcard expansion you should use an assignment like this:

abcversion=$(ls abc*)
echo "$abcversion"

abcga5

And also MadeInGermany is right when he says to remove the trailing slash in
export ABC_HOME=/opt/app/abc/$abcversion/ (unless abcga5 is a directory).

Note: think about what the script should do when more files match the wildcard. Test it.