How To Fix GL457 - Specify different files for the read and write functions

SAP Error Message - Details

• Message type: E = Error

• Message class: GL - FI-SL Rollup

• Message number: 457

• Message text: Specify different files for the read and write functions

What causes this issue?

You have specified the same export file for the read and write
functions. For technical reasons, this is not possible.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Enter a different file name.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message GL457 - Specify different files for the read and write functions ?

  The SAP error message GL457, which states "Specify different files for the read and write functions," typically occurs in the context of file handling in ABAP programs. This error indicates that the program is attempting to read from and write to the same file without properly differentiating between the two operations. Here’s a breakdown of the cause, solution, and related information:
  Cause:
  
  Same File for Read and Write: The most common cause of this error is that the program is trying to read from a file and write to the same file simultaneously. In ABAP, when you open a file for reading, you cannot also open it for writing without specifying different file names.
  File Mode Confusion: The file mode might not be correctly set, leading to confusion in the operations being performed on the file.
  
  Solution:
  
  
  Use Different File Names: Ensure that you are using different file names for the read and write operations. For example, if you are reading from input.txt, you should write to output.txt or any other distinct file name.
  DATA: lv_input_file  TYPE string VALUE 'input.txt',
        lv_output_file TYPE string VALUE 'output.txt'.
  
  
  Check File Open Modes: When opening files, make sure to specify the correct mode. For example, use OPEN DATASET with the appropriate options:
  
  For reading: OPEN DATASET lv_input_file FOR INPUT IN TEXT MODE.
  For writing: OPEN DATASET lv_output_file FOR OUTPUT IN TEXT MODE.
  
  
  
  Close Datasets Properly: Always ensure that you close the datasets after you are done with the read/write operations using CLOSE DATASET.
  
  
  Error Handling: Implement error handling to catch any issues that may arise during file operations. This can help in debugging and ensuring that the program behaves as expected.
  
  
  Related Information:
  
  ABAP Documentation: Refer to the official SAP documentation for OPEN DATASET, READ DATASET, and CLOSE DATASET for detailed syntax and examples.
  File Handling Best Practices: Familiarize yourself with best practices for file handling in ABAP to avoid common pitfalls.
  SAP Notes: Check SAP Notes for any specific issues related to file handling in your version of SAP, as there may be version-specific considerations.
  
  By following these guidelines, you should be able to resolve the GL457 error and ensure that your file operations in ABAP are functioning correctly.