1 files changed, 27 insertions, 4 deletions

diff --git a/src/lib/libc/string/strerror.3 b/src/lib/libc/string/strerror.3
index c9d8504dbb..05cb7e9d9c 100644
--- a/src/lib/libc/string/strerror.3
+++ b/src/lib/libc/string/strerror.3
@@ -33,12 +33,11 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.\"     from: @(#)strerror.3    6.9 (Berkeley) 6/29/91
-.\"     $Id: strerror.3,v 1.1.1.1 1995/10/18 08:42:22 deraadt Exp $
+.\"     $OpenBSD: strerror.3,v 1.5 2002/11/21 20:45:05 marc Exp $
 .\"
 .Dd June 29, 1991
 .Dt STRERROR 3
-.Os BSD 4
+.Os
 .Sh NAME
 .Nm strerror
 .Nd get error message string
@@ -46,15 +45,35 @@
 .Fd #include <string.h>
 .Ft char *
 .Fn strerror "int errnum"
+.Ft int
+.Fn strerror_r "int errnum" "char *strerrbuf" "size_t buflen"
 .Sh DESCRIPTION
 The
 .Fn strerror
 function returns a pointer to the language-dependent error message
-string affiliated with an error number.
+string affiliated with the specified error number
+.Fa errnum .
+The returned string contains a maximum of
+.Dv NL_TEXTMAX
+characters, including the trailing NUL.
 .Pp
 The array pointed to is not to be modified by the program, but may be
 overwritten by subsequent calls to
 .Fn strerror .
+.Pp
+.Fn strerror_r
+is a thread safe version of
+.Fn strerror
+that places the error message in the given buffer
+.Fa strerrbuf .
+If the error message is larger then
+.Fa buflen
+the message will be truncated to fit within buflen and
+.Er ERANGE
+is returned.
+.Fn strerror_r
+returns zero upon successful completion.
+An error number is returned, otherwise.
 .Sh SEE ALSO
 .Xr intro 2 ,
 .Xr perror 3 ,
@@ -64,3 +83,7 @@ The
 .Fn strerror
 function conforms to
 .St -ansiC .
+The
+.Fn strerror_r
+function conforms to
+.St -p1003.1 .