HP Fortran Programmer's Reference (September 2007)

HP Fortran statements
BACKSPACE
Chapter 10282
BACKSPACE
Positions file at preceding record.
Syntax
The syntax of the BACKSPACE statement can take one of two forms:
• Short form:
BACKSPACE integer-expression
• Long form:
BACKSPACE ( io-specifier-list )
integer-expression
is the number of the unit connected to a sequential file.
io-specifier-list
is a list of the following comma-separated I/O specifiers:
[UNIT=] unit
specifies the unit connected to an external file opened for sequential access.
unit must be an integer expression that evaluates to a number greater than
0. If the optional keyword UNIT= is omitted, unit must be the first item in
io-specifier-list .
ERR= stmt-label
specifies the label of an executable statement to which control passes if an
error occurs during statement execution.
IOSTAT= integer-variable
returns the I/O status after the statement executes. If the statement
executes successfully, integer-variable is set to zero. If an error occurs, it
is set to a positive integer that indicates which error occurred.
Description
The BACKSPACE statement causes the external file connected to unit to be positioned just
before the preceding record of the file. The file must be connected for sequential access.