Bash function behaves differently in script than when entered manually on command line, why?

Question

running - ./bashfile.sh a 1 1

#!/bin/bash

addit () {
echo $(($2 + $3))
}

if [ $1 == a ]
then
addit
fi

produces

syntax error: operand expected (error token is "+ ")

What is causing this problem?

Thanks

You should call your addit function in the script, something like: addit $1 $2, after the definition of addit. — rendon
– rendon, Commented Oct 19, 2014 at 4:40
In my haste I neglected that the function is called inside of an if statement. I have added it now, sorry. — derrend
– derrend, Commented Oct 19, 2014 at 5:17
The parameters that addit see are those you pass to the function, not those that are passed to the script. Call addit with $2 and $3 as I show you in my answer. — rendon
– rendon, Commented Oct 19, 2014 at 5:24

rendon · Accepted Answer · 2014-10-19 04:45:37Z

2

You should call your addit function in the script, something like: addit $1 $2, after the definition of addit.

#!/bin/bash
addit () {
    echo $(($1 + $2))
}

addit $1 $2

Running:

chmod +x bashfile.sh
./bashfile 1 1
2

answered Oct 19, 2014 at 4:45

rendon

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