(usage): Warn about mixing use of `-r' with FIFOs and

other special files like /dev/zero.

diff --git a/src/cp.c b/src/cp.c
index 3e5773b4fef593157e1477d245feedea74d1dc67..f85ef234d68421c6def2e2d10928e9d358610be1 100644 (file)
--- a/src/cp.c
+++ b/src/cp.c
@@ -145,6 +145,8 @@ Copy SOURCE to DEST, or multiple SOURCE(s) to DIRECTORY.\n\
   -p, --preserve               preserve file attributes if possible\n\
   -P, --parents                append source path to DIRECTORY\n\
   -r                           copy recursively, non-directories as files\n\
+                                 WARNING: use -R instead when you might copy\n\
+                                 special files like FIFOs or /dev/zero\n\
       --sparse=WHEN            control creation of sparse files\n\
   -R, --recursive              copy directories recursively\n\
   -s, --symbolic-link          make symbolic links instead of copying\n\