File Headers: Finding Out the Method Used to Create the Transport File

The method for finding out how the transport file was created (XPORT engine with PROC COPY or PROC CPORT and PROC CIMPORT) depends on your operating environment.

Under operating environments that store character data in ASCII format, use a text editor or an operating environment read or view command to read the file.
The XPORT engine creates a file whose first 40 characters contain this ASCII text:
```
HEADER RECORD*******LIBRARY HEADER RECORD!!!!!!!00
```
PROC CPORT creates a file whose first 40 characters contain this ASCII text:
```
**COMPRESSED** **COMPRESSED** **COMPRESSED** **COM
```
Note: If you specify the NOCOMPRESS option in PROC CPORT, compression is suppressed, which prevents the display of the preceding text in a transport file.

For technical details about the transport format that is used for a data set, see Technical Support article TS-140, The Record Layout of a SAS Transport Data Set.
Under z/OS, because the transport format uses ASCII encoding, non-ASCII operating environments such as z/OS cannot read them in a text editor. For more information, see Reading Transport Files in z/OS Operating Environments.