ferror.3: CAVEATS: Need to get EOF before calling these functions

Signed-off-by: Alejandro Colomar <alx@kernel.org>

1 files changed, 14 insertions, 0 deletions

diff --git a/man3/ferror.3 b/man3/ferror.3
index b969aa01b..6e2818d4a 100644
--- a/man3/ferror.3
+++ b/man3/ferror.3
@@ -101,6 +101,20 @@ that these functions shall not change the value of
 if
 .I stream
 is valid.
+.SH CAVEATS
+Normally,
+programs should read the return value of an input function,
+such as
+.BR fgetc (3),
+before using functions of the
+.BR feof (3)
+family.
+Only when the function returned the sentinel value
+.B EOF
+it makes sense to distinguish between the end of a file or an error with
+.BR feof (3)
+or
+.BR ferror (3).
 .SH SEE ALSO
 .BR open (2),
 .BR fdopen (3),