Variable Assignment


 
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# 1  
Old 07-17-2016
Variable Assignment

Hi

I am facing a problem.

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

echo "$ABC_HOME"

It prints
Code:
/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  
Old 07-17-2016
When you assign
Code:
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:
Code:
 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:
Code:
abcversion=abc*


Last edited by Ivo Breeden; 07-17-2016 at 09:06 PM.. Reason: typos
# 3  
Old 07-17-2016
I tried removing the quotes and here are the results:

Code:
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 )

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

echo "$ABC_HOME"

/opt/app/abc/abc*/

but I need this:

Code:
/opt/app/abc/abcga5

# 4  
Old 07-18-2016
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:
Code:
echo $ABC_HOME

However, if there are multiple matches then you would get this:
Code:
echo $ABC_HOME
/opt/app/abc/abcga5 /opt/app/abc/abcga6 /opt/app/abc/abcga7

# 5  
Old 07-18-2016
Hi

Its still not working. i removed quotes from everything:

See below:

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

echoresult:

Code:
abcga5

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

echo $ABC_HOME

echoresult:
Code:
/opt/app/abc/abc*/

# 6  
Old 07-18-2016
Remove the trailing /
Otherwise only matching directories are displayed.
# 7  
Old 07-18-2016
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:
Code:
abcversion=abc*
echo "$abcversion"

abc*

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