The file handler allows you to configure your IO options beyond what COBOL IO statements give you.
Here are a few configurable options:
DATAFILE Maps the file name, passed to an OPEN statement, onto another name.
EXPANDPOSITIONING When using the WRITE AFTER POSITIONING statement (OS/VS COBOL compatibility), determines whether the written record includes carriage control information.
EXPANDTAB Determines whether to expand TAB characters, encountered in line sequential or line advancing files during a READ operation, into the equivalent number of spaces.
INSERTNULL When performing WRITE or REWRITE operations on line sequential or line advancing files, determines whether to insert NULL (x"00") characters before non-printable characters. Also determines whether to strip out those NULL characters during READ operations.
RUNITLOCKDETECT Specifies whether you can detect that a record has been locked by a separate OPEN statement issued from within the same run unit.
STRIPSPACE When performing WRITE or REWRITE operations on line sequential or line advancing files, determines whether to remove trailing space characters.
WRITETHRU Determines whether to write file modifications out to disk immediately. Alternatively, the modifications may be buffered internally, either by the COBOL system or by the operating system, and flushed to disk at a later stage.
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