BACKSPACE in a terminal file has no effect.
u must be connected for sequential access. Execution of a BACKSPACE statement on a direct-access file is not defined in the FORTRAN 77 Standard, and is unpredictable. We do not recommend using a BACKSPACE statement on a direct-access file or an append access file.
Execution of the BACKSPACE statement modifies the file position, as follows:
Prior to Execution |
After Execution |
Beginning of the file |
Remains unchanged |
Beyond the endfile record |
Before the endfile record |
Beginning of the previous record |
Start of the same record |