DFSORT scans control statements for syntax and content errors, such as invalid operators, operands, or operand values, missing operands, and missing or invalid delimiters.

As explained in Printing messages and control statements and Printing EFS messages and control statements, DFSORT prints messages and control statements as requested by the SORTDIAG DD statement, MSGPRT, LIST, and LISTX operands. The following paragraphs assume that messages and control statements are to be printed.

DFSORT scans each control statement for errors, and prints an error message for the first error detected. Scanning stops at the first error, and then continues with the next control statement. If DFSORT detects an error, it usually terminates after all the control statements are scanned. However, in some cases, detection of an error by the Blockset technique results in the use of another technique that could avoid termination, and, in other cases, Blockset terminates immediately without completing control statement scanning.

If an error is associated with a specific operator, operand or value for a control statement in DFSPARM, SYSIN, and SORTCNTL, DFSORT prints a marker ($) directly below the control statement near the error. If an error is associated with a specific control statement, DFSORT prints the error message directly below the marker line or control statement.

If an error is associated with a specific control statement returned by an Extended Function Support (EFS) program, the EFS program can return a message to be printed with that control statement. The associated message must be returned at the same time the control statement is returned to DFSORT. The EFS program can also return an offset pointing to the error found in the control statement. DFSORT uses this offset to place a marker ($) below the control statement. Any message associated with the control statement is printed directly below the marker line or control statement. See the z/OS DFSORT Application Programming Guide for more information about Extended Function Support.