( i * x fileid
-- j * x
from the stack. Save the current input
source specification, including the current value of
. Store fileid
Make the file specified by fileid
the input source. Store
zero in BLK
. Other stack effects are due to the
Repeat until end of file: read a line from the file, fill the
input buffer from the contents of that line, set >IN
to zero, and interpret.
Text interpretation begins at the file position where the next
file read would occur.
When the end of the file is reached, close the file and restore
the input source specification to its saved value.
An ambiguous condition exists if fileid
is invalid, if
there is an I/O exception reading fileid
, or if an I/O
exception occurs while closing fileid
. When an ambiguous
condition exists, the status (open or closed) of any files that
were being interpreted is implementation-defined.