Guardian Procedure Calls Reference Manual (G06.25+)

Guardian Procedure Calls (A-B)
Guardian Procedure Calls Reference Manual—522629-013
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BACKSPACEEDIT Procedure
BACKSPACEEDIT Procedure
Summary
Syntax for C Programmers
Syntax for TAL Programmers
Parameters
Related Programming Manual
Summary
The BACKSPACEEDIT procedure sets the current record number of an IOEdit file to
that of the line preceding what was the current record before the call. The following
rules describe the operation of BACKSPACEEDIT:
•
If the current record number is -1 (which occurs when the file is empty or when the
file is positioned at the beginning, as when it is just opened), BACKSPACEEDIT
does nothing.
•
If the current record number is -2 (which occurs when the current record number
has been incremented beyond the last record in the file), the current record
number is set to the highest record number in the file. If the file is empty, the
current record number is set to -1.
•
If the current record number is 0 or greater, the current record number is set to the
highest record number in the file that is less than the current record number before
the call; if there is no such record, the current record number is set to -1.
BACKSPACEEDIT is an IOEdit procedure and can only be used with files that have
been opened by OPENEDIT or OPENEDIT_.
Syntax for C Programmers
Syntax for TAL Programmers
#include <cextdecs(BACKSPACEEDIT)>
short BACKSPACEEDIT ( short filenum );
error := BACKSPACEEDIT ( filenum ); ! i