hex() is used to return decimal value for the given hexadecimal value.

    hex EXPR
    hex

If the first format is used "EXPR" can specify the format of the hexadecimal format, whether it is 0,0x,0b, otherwise it uses a "$" as default.

    #! C:\programfiles\perl\bin\perl
    print "content-type: text/html\n\n";
    print hex '0xae';
    print "<br>";
    print hex 'aE';

    174
    174

In the above example, first statement the hexadecimal value is like an expression since "ox" is used, then in the second statement considers the hexadecimal value as a string but both the statements returns the same result "174".