diff --git a/lib/libc/gen/ttyname.3 b/lib/libc/gen/ttyname.3 index 9420bbe8f9e4..9e8a4f099598 100644 --- a/lib/libc/gen/ttyname.3 +++ b/lib/libc/gen/ttyname.3 @@ -28,7 +28,7 @@ .\" @(#)ttyname.3 8.1 (Berkeley) 6/4/93 .\" $FreeBSD$ .\" -.Dd May 14, 2005 +.Dd July 18, 2014 .Dt TTYNAME 3 .Os .Sh NAME @@ -76,6 +76,14 @@ function takes a buffer and length as arguments to avoid this problem. .Sh RETURN VALUES The +.Fn isatty +function returns 1 if +.Fa fd +refers to a terminal type device; +otherwise, it returns 0 and may set +.Va errno +to indicate the error. +The .Fn ttyname function returns the null terminated name if the device is found and @@ -89,15 +97,23 @@ The function returns 0 if successful. Otherwise an error number is returned. .Sh ERRORS -The -.Fn ttyname_r -may fail and return the following error codes: +These functions may fail if: .Bl -tag -width Er -.It Bq Er ENOTTY +.It Bq Er EBADF The .Fa fd argument is not a valid file descriptor. +.It Bq Er ENOTTY +The file associated with +.Fa fd +is not a terminal. +.El +.Pp +Additionally, +.Fn ttyname_r +may fail if: +.Bl -tag -width Er .It Bq Er ERANGE The .Fa bufsize