CODEWITHSUNDEEP
shell
user3884278
user3884278

Reputation: 1

ksh not evaluating variables read from a file

Question is how to evaluate the complete $variable read from a file.

I have a program combination of python and ksh shell. ksh shell executes a python script which reads xmlfile & returns back a classpath & vairables to export & command to execute.

In my case the xml files looks like the following 

  1<script>
  2          <scriptPath>/home/opapp/apps/ampFeed</scriptPath>
  3         <JAVA_HOME>/local/opt/sunjava-1.6.0_01/jre</JAVA_HOME>
  4         <classpath>"./properties/prod"</classpath>
  5         <classpath>"lib/activation.jar"</classpath>
  6         <classpath>"lib/antlr-2.7.6.jar"</classpath>
           .......
  40         <executionCmd>"$JAVA_HOME/bin/java"</executionCmd>
  43        <executionCmd>"-Dtarget.db.properties=/home/opapp/apps/ampFeed/properties/pr        od"</executionCmd>
  44         <executionCmd>"-classpath"</executionCmd>
           ..........
   </script>

My Shell script is very simple 

$0 == XMlFile
typeset -x JAVA_HOME=`${HOME}/scripts/readXmlFile.py -s $0 -e "JAVA_HOME"
typeset -x CLASSPATH=`${HOME}/scripts/readXmlFile.py -s $0 -e "CLASSPATH"
EXECUTION_CMD=`${HOME}/scripts/readXmlFile.py -s $0 -e "CLASSPATH"

export JAVA_HOME
export CLASSPATH
print JAVA_HOME=$JAVA_HOME
print CLASSPATH=$CLASSPATH
print EXECUTION_CMD=$EXECUTION_CMD

$EXECUTION_CMD

Output is the following :-

JAVA_HOME="/local/opt/java7/jre"
CLASSPATH=:"./properties/dev1":"lib/activation.jar":"lib/antlr-2.7.6.jar":"lib/aopalliance.jar"
EXECUTION_CMD="$JAVA_HOME/bin/java" -Dtarget.db.properties=/home/opappqa/apps/Feed/properties/dev1" "-classpath" "$CLASSPATH" "ampFeed.generator.FeedGenerator" "-Xms128M" "-Xmx512M"
line 41: "$JAVA_HOME/bin/java": not found

Question is how to evaluate the complete CLASSPATH & JAVA_HOME

Upvotes: 0

Views: 103

Answers (1)

Charles Duffy
Charles Duffy

Reputation: 295687

Use eval to treat the string as code:

eval "$EXECUTION_CMD"

Otherwise, POSIX sh behavior (which ksh follows) runs string-splitting and glob expansion parse phases only, not allowing any portion of the string to be treated as syntax.

That said, see BashFAQ #50 for information on best practices around programmatically generating code. (Some of the advice there is bash-only, but a great deal of it also applies to ksh).

Upvotes: 1

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