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Old 02-21-2011, 11:57 AM   #1
Mark8812
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Registered: Feb 2011
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Variable expansion in .bashrc not working as I expect it to


In my .bashrc file, I am attempting to set JAVA_PATH to a local path, using the HOME environment variable or '~' symbol as shown in the following examples.

Using ${HOME}

export JAVA_PATH='${HOME}/Software/java/jdk1.6.0_24'

When I attempt to use ${JAVA_HOME} in a my ${PATH} javec is not found. To debug it, I tried a simple ls command:

ls ${JAVA_HOME}

and get the following error:

ls: ${HOME}/Software/java/jdk1.6.0_24/: No such file or directory

Using '~':

Trying to use '~' symbol as follows:

export JAVA_PATH='~/Software/java/jdk1.6.0_24'

the ls command results in the same error, however javac is found.


I prefer the '~' symbol anyway, but would like to understand why the ls command does not work for either, and why it seems as though ${HOME} is not being expanded.
 
Old 02-21-2011, 12:09 PM   #2
bigrigdriver
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Quote:
export JAVA_PATH='${HOME}/Software/java/jdk1.6.0_24'
The single quotes are your undoing. Use double quotes.

To see why, try this simple test in a terminal:
echo '${HOME}' note the single quotes
echo "${HOME}" with double quotes

The first echo gives ${HOME}
The second echo gives /home/<your-user-name>

You can read more about variable expansion and the use of single and double quotes in the bash man pages, Bash Beginners Guide, and the Advanced Bash Scripting Guide.

Last edited by bigrigdriver; 02-21-2011 at 12:21 PM.
 
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Old 02-21-2011, 12:13 PM   #3
szboardstretcher
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Use double quotes.

Sorry -- took me a second to reply -- didn't see the previous poster's reply.
 
1 members found this post helpful.
  


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