find(1) . -type f -print0
search for files in a directory hierarchy
find [-H] [-L] [-P] [-D debugopts] [-Olevel] [path...] [expression]
-type c
       File is of type c:

       b      block (buffered) special

       c      character (unbuffered) special

       d      directory

       p      named pipe (FIFO)

       f      regular file

       l      symbolic link; this is never true if the -L option or the  -follow  option  is  in  effect,
              unless the symbolic link is broken.  If you want to search for symbolic links when -L is in
              effect, use -xtype.

       s      socket

       D      door (Solaris)
       True;  print  the  full file name on the standard output, followed by a null character (instead of
       the newline character that -print uses).  This allows file names that contain  newlines  or  other
       types  of  white space to be correctly interpreted by programs that process the find output.  This
       option corresponds to the -0 option of xargs.
source manpages: find