---
title: AEBuildDesc
framework: Core Services
role: symbol
role_heading: Function
platforms: [macOS 10.0+]
path: coreservices/1573758-aebuilddesc
---

# AEBuildDesc

Provides a facility for compiling AEBuild descriptor strings into Apple event descriptors (`AEDesc`).

## Declaration

```occ
OSStatus AEBuildDesc(AEDesc *dst, AEBuildError *error, const char *src, ...);
```

## Parameters

- `dst`: A pointer to a descriptor where the resulting descriptor should be stored. See [doc://com.apple.documentation/documentation/coreservices/aedesc](coreservices/aedesc.md).
- `error`: A pointer to an `AEBuildError` structure where additional information about any errors that occur will be saved. This is an optional parameter and you can pass `NULL` if this information is not required. See [doc://com.apple.documentation/documentation/coreservices/aebuilderror](coreservices/aebuilderror.md).
- `src`: An `AEBuild` format string describing the descriptor to be created.

## Return Value

A numeric result code indicating the success of the call. A value of `AEBuildSyntaxNoErr` (zero) means the call succeeded. You can use the `error` parameter to discover information about other errors. See also [Result Codes](../applicationservices/apple_event_manager.md).

## Discussion

This function and related “AEBuild” routines provide a very simple translation service for converting specially formatted strings into complex Apple event descriptors. Normally, creating complex Apple event descriptors requires a large number of calls to Apple event Manager routines to build up the descriptor piece by piece. The `AEBuildDesc` function and related routines allow you to consolidate all of the calls required to construct a complex Apple event descriptor into a single system call that creates the desired structure as directed by a format string that you provide.

For additional information on using the AEBuild routines, see the descriptions for [AEBuildAppleEvent](1573757-aebuildappleevent.md) and [AEBuildParameters](1573755-aebuildparameters.md).

### Version-Notes

Prior to OS X version 10.3, `AEBuildDesc` would fail if you supplied a data parameter with size greater than 32767 bytes.

## See Also

### Creating Apple Event Structures in Memory

- [AEBuildAppleEvent](1573757-aebuildappleevent.md)
- [AEBuildParameters](1573755-aebuildparameters.md)
- [AEPrintDescToHandle](1445158-aeprintdesctohandle.md)
- [vAEBuildAppleEvent](1441729-vaebuildappleevent.md)
- [vAEBuildDesc](1446775-vaebuilddesc.md)
- [vAEBuildParameters](1448040-vaebuildparameters.md)