The _fileinfo variable determines whether information about the open files of a process is passed to new processes by functions such as _spawn. _fileinfo is declared in STDLIB.H as
extern int _fileinfo;
If _fileinfo is 0 (the default), information about open files is not passed to new processes; otherwise the information is passed. You can modify the default value of _fileinfo by setting the _fileinfo variable to a nonzero value in your program.