Whether the Linux test file exists a command set __linux

       -B file file exists and is block special-c file file exists and is character sp
              ecial-d file file exists and is a directory-e file file Exists-f file File exists and is a regular file-g file file exists and is Set-group-id-g FIL E file exists and is owned by the effective group Id-h file file exists and is a Symbo LIC link (same as-l)-K file file exists and has its sticky bit set-l FILE FIL E exists and is a symbolic link (same as-h)-O file exists and is owned by the effective user I D-p file file exists and is a named Pipe-r file file exists and read Permissio N is granted-s file file exists and has a size greater than Zero-s file file E
  Xists and is a socket     -T FD file descriptor FD is opened on a terminal-u file file exists and it Set-user-id bit is  Set-w file file exists and Write permission is granted-x file file exists and Execute (or search) permission is granted