<function name="xpcall" parent="Global" type="libraryfunc"> <description> Attempts to call the first function. If the execution succeeds, this returns `true` followed by the returns of the function. If execution fails, this returns `false` and the second function is called with the error message. Unlike in <page>Global.pcall</page>, the stack is not unwound and can therefore be used for stack analyses with the <page>debug</page>. <bug issue="2036">This cannot stop errors from hooks called from the engine.</bug> <bug issue="2498">This does not stop <page>Global.Error</page> and <page>Global.ErrorNoHalt</page> (As well as <page>Global.include</page>) from sending error messages to the server (if called clientside) or calling the <page>GM:OnLuaError</page> hook. The success boolean returned will always return true and thus you will not get the error message returned. <page>Global.error</page> does not exhibit these behaviours.</bug> </description> <realm>Shared and Menu</realm> <args> <arg name="func" type="function">The function to call initially.</arg> <arg name="errorCallback" type="function">The function to be called if execution of the first fails; the error message is passed as a string. You cannot throw an <page>Global.error</page>() from this callback: it will have no effect (not even stopping the callback).</arg> <arg name="arguments" type="vararg">Arguments to pass to the initial function.</arg> </args> <rets> <ret name="" type="boolean">Status of the execution; `true` for success, `false` for failure.</ret> <ret name="" type="vararg">The returns of the first function if execution succeeded, otherwise the **first** return value of the error callback.</ret> </rets> </function> <example> <description>Using xpcall to catch an error.</description> <code> local function test() aisj() end local function catch( err ) print( "ERROR: ", err ) end print( "Output: ", xpcall( test, catch ) ) </code> <output> ``` ERROR: lua/wiki/xpcall_example.lua:2: attempt to call global 'aisj' (a nil value) Output: false nil ``` </output> </example>