Routines (alphabetical) > Routines: C > CDF Routines > CDF_SET_MD5CHECKSUM

# CDF_SET_MD5CHECKSUM

The CDF_SET_MD5CHECKSUM procedure calculates and inserts a MD5 checksum into a CDF file. If you use the /REMOVE keyword, a previously-inserted checksum is removed from the file.

By default, the checksums are not inserted into new files. Once the checksum is inserted into a particular file, a data integrity check of the file is performed every time it is opened. A new checksum is computed and stored when the file is closed. The overhead for this operation may be noticeable for large files. You may wish to remove the checksum once the integrity of the file has been verified.

## Examples

The following example calculates and inserts a MD5 checksum inside of a CDF file.

id = CDF_CREATE('myfile.cdf')

CDF_SET_MD5CHECKSUM, id

CDF_CLOSE, id

## Syntax

CDF_SET_MD5CHECKSUM, Id, [, /REMOVE]

## Arguments

### Id

The CDF ID, returned from a previous call to CDF_OPEN or CDF_CREATE.

## Keywords

### REMOVE

Remove a previously-created checksum from the CDF file.

## Version History

7.0.3 | Introduced