---
title: "AEPutDesc(_:_:_:)"
framework: coreservices
role: symbol
role_heading: Function
path: coreservices/1450093-aeputdesc
---

# AEPutDesc(_:_:_:)

Adds a descriptor to any descriptor list, possibly replacing an existing descriptor in the list.

## Declaration

```swift
func AEPutDesc(_ theAEDescList: UnsafeMutablePointer<AEDescList>!, _ index: Int, _ theAEDesc: UnsafePointer<AEDesc>!) -> OSErr
```

## Parameters

- `theAEDescList`: A pointer to the descriptor list to add a descriptor to. See doc://com.apple.documentation/documentation/coreservices/aedesclist.
- `index`: A one-based positive integer indicating the position to insert the descriptor at. If there is already a descriptor in the specified position, it is replaced. You can pass a value of zero or count + 1 to add the descriptor at the end of the list. AEPutDesc returns an error (AEIllegalIndex) if you pass a negative number or a value that is out of range.
- `theAEDesc`: A pointer to the descriptor to add to the list. See doc://com.apple.documentation/documentation/coreservices/aedesc.

## Return Value

Return Value A result code. See Result Codes.

## Discussion

Discussion Thread safe starting in OS X v10.2.

## See Also

### Adding Items to Descriptor Lists

- [AEPutArray(_:_:_:_:_:_:)](coreservices/1442535-aeputarray.md)
- [AEPutPtr(_:_:_:_:_:)](coreservices/1445287-aeputptr.md)