use stronger language when pointing people at strtol()

src/lib/libc/stdlib/atoi.3

@@ -33,7 +33,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.\"	$OpenBSD: atoi.3,v 1.3 1999/06/29 18:36:18 aaron Exp $
+.\"	$OpenBSD: atoi.3,v 1.4 1999/09/13 07:14:13 deraadt Exp $
 .\"
 .Dd June 4, 1993
 .Dt ATOI 3
@@ -60,6 +60,17 @@ It is equivalent to:
 .Bd -literal -offset indent
 (int)strtol(nptr, (char **)NULL, 10);
 .Ed
+.Sh CAVEATS
+.Nm
+does no overflow checking, handles unsigned numbers poorly,
+and handles strings containing trailing extra characters
+(like
+.Dq "123abc" Ns )
+poorly.  Careful use of
+.Xr strtol 3
+and
+.Xr strtoul 3
+can alleviate these problems.
 .Sh SEE ALSO
 .Xr atof 3 ,
 .Xr atol 3 ,