Running a Test with expression in a string

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I am trying to run the test command from a string. The string contains the expression.



 TEST="! -e ~/bin/xyz"
if [ `echo "$TEST"` ]; then
echo running "$TEST";
fi


However, the above if condition does evaluate to true but if I plug in the command directly (as below), it evaluates to false.



 if [ ! -e ~/bin/xyz ]; then
echo running;
fi


The second snippet's behavior is correct. Can someone help me understand why there is a difference and also how I can correct the first snippet to give me the right result?









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    up vote
    0
    down vote

    favorite












    I am trying to run the test command from a string. The string contains the expression.



     TEST="! -e ~/bin/xyz"
    if [ `echo "$TEST"` ]; then
    echo running "$TEST";
    fi


    However, the above if condition does evaluate to true but if I plug in the command directly (as below), it evaluates to false.



     if [ ! -e ~/bin/xyz ]; then
    echo running;
    fi


    The second snippet's behavior is correct. Can someone help me understand why there is a difference and also how I can correct the first snippet to give me the right result?









    share







    New contributor




    Ashwin is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
    Check out our Code of Conduct.





















      up vote
      0
      down vote

      favorite









      up vote
      0
      down vote

      favorite











      I am trying to run the test command from a string. The string contains the expression.



       TEST="! -e ~/bin/xyz"
      if [ `echo "$TEST"` ]; then
      echo running "$TEST";
      fi


      However, the above if condition does evaluate to true but if I plug in the command directly (as below), it evaluates to false.



       if [ ! -e ~/bin/xyz ]; then
      echo running;
      fi


      The second snippet's behavior is correct. Can someone help me understand why there is a difference and also how I can correct the first snippet to give me the right result?









      share







      New contributor




      Ashwin is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.











      I am trying to run the test command from a string. The string contains the expression.



       TEST="! -e ~/bin/xyz"
      if [ `echo "$TEST"` ]; then
      echo running "$TEST";
      fi


      However, the above if condition does evaluate to true but if I plug in the command directly (as below), it evaluates to false.



       if [ ! -e ~/bin/xyz ]; then
      echo running;
      fi


      The second snippet's behavior is correct. Can someone help me understand why there is a difference and also how I can correct the first snippet to give me the right result?







      linux test





      share







      New contributor




      Ashwin is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.










      share







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      Ashwin is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.








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      Ashwin is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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      asked 7 mins ago









      Ashwin

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      Ashwin is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.






      Ashwin is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.

























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