I use the following code to execute shell command, the issue is that when I put it as parameter which I should get from user it doesn’t work but If I put it hard-coded it works.
Working
VAL=`./test a | grep '^.(bpassb)?.$' | cut -d ' ' -g1`
Not working
VAL=`./test a | grep ${param} | cut -d ' ' -g1`
In the not working version which I do cat to param I see the value printed OK, what could I miss when I pass ${param} ?
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Answer
Parameters in shell are $1 $2 $3 etc… Right now what you typed is empty data.
You might need to put “” around the $1 parameter. And make sure that the value of $1 is indeed the correct value.