Arguments

 

fd1

   The file associated with this file descriptor in the parent
   process is associated with file descriptor number 0 (stdin) in
   the child process. If -1 is specified, the file associated with
   the parent's file descriptor number 0 is used (the default).
 

fd2

   The file associated with this file descriptor in the parent
   process is associated with file descriptor number 1 (stdout) in
   the child process. If -1 is specified, the file associated with
   the parent's file descriptor number 1 is used (the default).
 

fd3

   The file associated with this file descriptor in the parent
   process is associated with file descriptor number 2 (stderr) in
   the child process. If -1 is specified, the file associated with
   the parent's file descriptor number 2 is used (the default).