Return type: Switch
Returns: Returns true if the named file exists and false otherwise.
file string-expression exists
An operator that tests whether a named file exists. Useful for avoiding overwriting a file that already exists with a new one.
For example, the following shows how a
file...exists test can be used to avoid overwriting an existing file:
global stream error-strm
do when file "errors.log" exists
put #error "File errors.log already exists.%n"
put #error "Please delete or rename it before running this program.%n"
halt with 1
open error-strm as file "errors.log"