1 files changed, 69 insertions, 22 deletions

diff --git a/src/lib/libc/string/strdup.3 b/src/lib/libc/string/strdup.3
index 925cbf3d46..45a7bd1826 100644
--- a/src/lib/libc/string/strdup.3
+++ b/src/lib/libc/string/strdup.3
@@ -1,5 +1,7 @@
-.\" Copyright (c) 1990, 1991 The Regents of the University of California.
-.\" All rights reserved.
+.\"     $OpenBSD: strdup.3,v 1.19 2011/12/08 08:06:19 lum Exp $
+.\"
+.\" Copyright (c) 1990, 1991, 1993
+.\"     The Regents of the University of California.  All rights reserved.
 .\"
 .\" Redistribution and use in source and binary forms, with or without
 .\" modification, are permitted provided that the following conditions
@@ -9,11 +11,7 @@
 .\" 2. Redistributions in binary form must reproduce the above copyright
 .\"    notice, this list of conditions and the following disclaimer in the
 .\"    documentation and/or other materials provided with the distribution.
-.\" 3. All advertising materials mentioning features or use of this software
-.\"    must display the following acknowledgement:
-.\"     This product includes software developed by the University of
-.\"     California, Berkeley and its contributors.
-.\" 4. Neither the name of the University nor the names of its contributors
+.\" 3. Neither the name of the University nor the names of its contributors
 .\"    may be used to endorse or promote products derived from this software
 .\"    without specific prior written permission.
 .\"
@@ -29,37 +27,86 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.\"     from: @(#)strdup.3      5.3 (Berkeley) 4/19/91
-.\"     $Id: strdup.3,v 1.1.1.1 1995/10/18 08:42:22 deraadt Exp $
+.\"     @(#)strdup.3    8.1 (Berkeley) 6/9/93
 .\"
-.Dd April 19, 1991
+.Dd $Mdocdate: December 8 2011 $
 .Dt STRDUP 3
 .Os
 .Sh NAME
-.Nm strdup
+.Nm strdup ,
+.Nm strndup
 .Nd save a copy of a string
 .Sh SYNOPSIS
 .Fd #include <string.h>
 .Ft char *
-.Fn strdup "const char *str"
+.Fn strdup "const char *s"
+.Ft char *
+.Fn strndup "const char *s" "size_t maxlen"
 .Sh DESCRIPTION
 The
 .Fn strdup
-function
-allocates sufficient memory for a copy
-of the string
-.Fa str ,
+function allocates sufficient memory for a copy of the string
+.Fa s ,
 does the copy, and returns a pointer to it.
-The pointer may subsequently be used as an
-argument to the function
+The pointer may subsequently be used as an argument to the function
 .Xr free 3 .
+.Pp
+The
+.Fn strndup
+function behaves similarly to
+.Nm strdup
+but only copies up to
+.Fa maxlen
+characters from
+.Fa s .
+The resulting string is always NUL-terminated.
+.Pp
+If insufficient memory is available,
+.Dv NULL
+is returned.
+.Sh EXAMPLES
+The following will point
+.Va p
+to an allocated area of memory containing the NUL-terminated string
+.Qq foobar :
+.Bd -literal -offset indent
+char *p;
+
+p = strdup("foobar");
+if (p == NULL)
+        err(1, NULL);
+.Ed
+.Sh ERRORS
+The
+.Fn strdup
+and
+.Fn strndup
+functions may fail and set the external variable
+.Va errno
+for any of the errors specified for the library function
+.Xr malloc 3 .
 .Sh SEE ALSO
 .Xr free 3 ,
 .Xr malloc 3 ,
-.Xt strcpy 3 ,
-.Xt strlen 3
+.Xr strcpy 3 ,
+.Xr strlcpy 3 ,
+.Xr strlen 3 ,
+.Xr wcsdup 3
+.Sh STANDARDS
+The
+.Fn strdup
+and
+.Fn strndup
+functions conform to
+.St -p1003.1-2008 .
 .Sh HISTORY
 The
 .Fn strdup
-function
-.Ud .
+function first appeared in
+.Bx 4.3 Reno .
+The
+.Fn strndup
+function appeared in glibc 2.0, was reimplemented for
+.Nx 4.0 ,
+and ported to
+.Ox 4.8 .