Opens the file named
filename named for reading and writing.
The read and write position is initially set to the end of the old file, if any.
Each open file has only one position, for both reading and writing.
If a file opened for update is both READER and WRITER at the same time, then SETREADPOS also affects WRITEPOS and vice versa.
Also, if you alternate reading and writing the same file, you must SETREADPOS between a write and a read, and SETWRITEPOS between a read and a write.
filename can also be the reserved word
"clipboard to read/write data to the clipboard just like a file.
binarymode is a boolean value (TRUE or FALSE).
binarymode is FALSE or not given, then the file is read/written as a text file.
That is, the end-of-line sequence is converted from LF to CRLF when written and from CRLF to LF when read.
binarymode is TRUE, then the file is written as a binary file.
That is, no end-of-line sequence conversion is performed.
OPENWRITE "dummy.fil SETWRITE "dummy.fil PRINT "Hello PRINT [Good Bye] SETWRITE  CLOSE "dummy.fil OPENUPDATE "dummy.fil SETREAD "dummy.fil SETREADPOS 0 SHOW READLIST[Hello]
SETWRITE "dummy.fil SETWRITEPOS 7 PRINT [And how are you today] SETWRITE  SETREAD "dummy.fil SETREADPOS 0 REPEAT 3 [SHOW READLIST][Hello] [And how are you today]