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6-10
where
'unit'
is
an
external
unit
specifier
and
'arg-list'
is
a list
of
arguments
as
described
for
the
BACKSPACE
statement
(section
6.2.3).
If
the specified file
is
already
positioned
at
its initial
point,
or
if
the
file is
connected
but
does
not
exist,
the
REWIND
statement
has
no
effect.
If
an
end-of-file
condition
has
occurred,
the
file
can
still be
rewound.
Examples:
REWIND 3
REWIND
(3,
IOSTAT=
ERRFLG,
ERR=
1030)
6.2.5 ENDFILE Statement
When
the
ENDFILE
statement
is
executed,
the
record
preceding
the
ENDFILE
becomes
the
last
record
of
the
file.
No
data-transfer
I/O
statement
can
be
executed
on
the file
without
first issuing a
BACKSPACE
or
REWIND
statement.
The
file
must
be
connected
for
sequential
access
when
ENDFILE
is
issued.
The
possible
formats
of
the
ENDFILE
statment
are
ENDFILE
unit
ENDFILE (arg-list)
where
'unit'
is
an
external
unit specifier
and
'arg-list'
is
a list
of
arguments
as
described
for
the
BACKSPACE
statement
(6.2.3).
I
f the file
can
be
connected
for direct access
also,
only
those
records
appearing
before
the
end-of-file
record
can
be
read
during
subsequent
direct access
operations.
I f a file
is
preconnected
to
a unit
but
does
not
yet exist, specifying
the
unit
in
an
ENDFI
LE
statement
causes
the
file
to
be
created.
Examples:
ENDFILE 3
ENDFILE
(3,
ERR = 1040)
6.3 Data-Transfer
1/0
Statements
Once
a file
has
been
connected
to
a
unit,
data
in
the
file
can
be
read
using
the
READ
statement,
or
data
can
be
written
into
the file using
the
WRITE
or
PRINT
statements.
Note
that
the
keyword
'PRINT'
does
not
imply
that
an
output
file
is
connected
to
a line
printer,
nor
does
the
keyword
'WRITE'
imply
that
it is
not.
6.3.1 READ Statement
The
READ
statement
reads
data
from
a specified
unit.
Its
possible
formats
are
READ
(ctl-list)
[in-list]
READ f [,in-list]
where
etl-Iist
in-list
f
is a list
of
control
information
specifiers
is
a list
of
the
data
to
be
read
is a
format
identifier,
and
is
the
same
as
the
'FMT
=
f'
specifier in
'ctl-list.'
FORTRAN-80