An if statement in shell scripting looks something like this:

if [ "$VAR" = 1 ] then #do something elif [ "$VAR" = 2 ] then #do something else else #do something by default fi

Notice we’re quoting the variable to protect from shell expansion.

There are a variety of file tests one can use:

if [ -e /tmp/test.file ] then #do something elif [ -d "$VAR" ] then #do something else else #another default action fi

There is also a variety of comparison operators one can use:

if [ -z "$a" ] #checking if $a is null then #do something elif [ "$a" != "$b" ] #checking if $a is not equal to $b then #do something else #do something default fi

Bash variables are not typed. They are all character strings, but in certain contexts and if the variable contains only digits, the shell will allow integer operations and comparisons. An excellent primer on variables is located here.