Returns the value for the session attribute attr within the currently active session sesshdl.

To obtain an attribute value, attr should have a format of IO_ATTR_NAME, where NAME is different for a specific attribute. The session attributes that can be used with this function are listed in the ACL Attribute Name column of the Attributes names for developers section of your adapter documentation. This function can accept sess attribute names and will not accept dobj attribute names.

If the specified attr is a repeating attribute, you can supply a string with the attribute name and array index (for example, attrname[idx]) to access the desired entry in the array.

If the operation fails, the function writes error data to $main::ioerr and returns a zero (0).