# Blob A **Blob** object represents a chunk of binary data. Scripting languages like *VBScript* and *JScript* have no built-in support for binary data - this object can be used to allocate a chunk of memory and manipulate it in a similar way to low-level languages like C. You can use **Blob** objects in conjunction with the [**File**](https://chaoses-ib.gitbook.io/directory-opus/manual/reference/scripting_reference/scripting_objects/file) object to read or write binary data from or to disk files. **Blob** objects are convertible to and from two types of ActiveX arrays - a *SAFEARRAY* of type *VT\_UI1* (known as an **array**) and a *SAFEARRAY* of type *VT\_VARIANT*, with each variant holding a *VT\_UI1* (known as a **VB array**). You can initialize a **Blob** with either of these two types of array (either when creating it via the **DOpusFactory.Blob** method or with the **Blob.CopyFrom** method), and you can also convert a **Blob** back to an array with the **ToArray** and **ToVBArray** methods. Support for these array types is dependent on the scripting language. You can read and write individual bytes within the **Blob** by indexing the byte offset starting from 0. For example, *my\_blob(5) = 128* would set the value of the sixth byte in the blob to 128. | Property Name | Return Type | Description | | ------------- | ------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | size | *object:*[**FileSize**](https://chaoses-ib.gitbook.io/directory-opus/manual/reference/scripting_reference/scripting_objects/filesize) | Returns a [**FileSize**](https://chaoses-ib.gitbook.io/directory-opus/manual/reference/scripting_reference/scripting_objects/filesize) object representing the size of this **Blob** in bytes. | | Method Name | **Arguments** | Return Type | Description | | ----------- | --------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Compare |

<Blob:source>
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Compares the contents of this Blob against another Blob (or array). By default the entire contents of the two blobs are compared. The optional parameters that let you configure the operation are:

to - specifies the byte offset within this Blob to compare against. Defaults to 0.
from - specifies the byte offset within the source Blob to compare with. Defaults to 0.
size - specifies the number of bytes to compare. Defaults to the full size of the source Blob.

The return value is 0 if the two blobs are the same. A value of -1 indicates this blob is less than the other blob, and 1 indicates this blob is greater than the other blob.

| | CopyFrom |

<Blob:source>
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or

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| *none* |

Copies data from the source Blob (or array) into this Blob. By default the entire contents of the source Blob will be copied over the top of this one. The optional parameters that let you configure the operation are:

to - specifies the byte offset within this Blob to copy to. Defaults to 0.
from - specifies the byte offset within the source Blob to copy from. Defaults to 0.
size - specifies the number of bytes to copy. Defaults to the full size of the source Blob.

As well as copying from another Blob, you can use this method to initialise a Blob from a string. By default the Blob will be set to the Unicode form of the string; if you pass "utf8" as the second parameter it will initialise the Blob with the UTF8-encoded form of the string.

If this Blob is not currently large enough to contain the copied data it will be resized automatically.

| | Find |

<Blob:search>
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| *object:*[**FileSize**](https://chaoses-ib.gitbook.io/directory-opus/manual/reference/scripting_reference/scripting_objects/filesize) |

Searches the contents of this Blob for the data contained in another Blob (or array). By default the entire contents of this Blob are searched. The optional from parameter lets you specify the starting position for the search, and the optional size parameter lets you specify the length of data in this Blob to search through.
The return value is -1 if the search data were not found, otherwise the offset from the start of the Blob data is returned.

| | Free | *none* | *none* | Frees the memory associated with this **Blob** and resets its size to 0. | | Init | *none* | *none* | Initialises the contents of the **Blob** (every byte within the blob will be set to 0). Equivalent to *Set(0)*. | | Resize | \ | *none* | Resizes the **Blob** to the specified number of bytes. | | Reverse | *none* | *none* | Reverses the contents of the **Blob**. | | Set |

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| *none* | Sets the contents of the **Blob** to the specified byte value (every byte within the blob will be set to that value). By default the whole **Blob** will be affected. The option *to* parameter lets you specify a byte offset to start at, and the optional *size* parameter lets you control the number of bytes affected. | | ToArray |

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SAFEARRAY of
VT\_UI1

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Converts the contents of this Blob to a SAFEARRAY of type VT\_UI1. By default the entire contents of the Blob will be copied to the array. The optional parameters that let you configure the operation are:
from - specifies the byte offset within the source Blob to copy from. Defaults to 0.
size - specifies the number of bytes to copy. Defaults to the full size of the source Blob.

| | ToVBArray |

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SAFEARRAY of
VT\_VARIANT

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Converts the contents of this Blob to a SAFEARRAY of type VT\_VARIANT. Each variant in the array contains a VT\_UI1. By default the entire contents of the Blob will be copied to the array. The optional parameters that let you configure the operation are:

from - specifies the byte offset within the source Blob to copy from. Defaults to 0.
size - specifies the number of bytes to copy. Defaults to the full size of the source Blob.

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