Question

Could someone explain what they mean where they are being used?

if(m/DROP TABLE IF EXISTS \`?$tableName\`?/ || m/CREATE TABLE \`?$tableName\`?/){
           $inside=1
}; 

-Thanks

Answer 1

A ? makes the character before it optional, which in this case is the `. In a high-level, this means that the author of that code is allowing for $tablename or `$tablename`.

Note that the regular expression as stated also matches `$tablename and $tablename`, but such a case is probably very unlikely. One can modify it to exclude such cases by using backreferences:

m/DROP TABLE IF EXISTS (\`?)$tableName\1 || m/CREATE TABLE (\`?)$tableName\2/

Further reading on this operator can be found here.