Bash if statement with multiple conditions throws an error

Question

I\'m trying to write a script that will check two error flags, and in case one flag (or both) are changed it\'ll echo-- error happened. My script:

my_error_f         


        

Answer 1

You can use either [[ or (( keyword. When you use [[ keyword, you have to use string operators such as -eq, -lt. I think, (( is most preferred for arithmetic, because you can directly use operators such as ==, < and >.

Using [[ operator

a=$1
b=$2
if [[ a -eq 1 || b -eq 2 ]] || [[ a -eq 3 && b -eq 4 ]]
then
     echo "Error"
else
     echo "No Error"
fi

Using (( operator

a=$1
b=$2
if (( a == 1 || b == 2 )) || (( a == 3 && b == 4 ))
then
     echo "Error"
else
     echo "No Error"
fi

Do not use -a or -o operators Since it is not Portable.