1.\" Copyright (c) 1990, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)strdup.3 8.1 (Berkeley) 6/9/93 29.\" $FreeBSD$ 30.\" 31.Dd June 6, 2018 32.Dt STRDUP 3 33.Os 34.Sh NAME 35.Nm strdup , 36.Nm strndup 37.Nd save a copy of a string 38.Sh LIBRARY 39.Lb libc 40.Sh SYNOPSIS 41.In string.h 42.Ft char * 43.Fn strdup "const char *str" 44.Ft char * 45.Fn strndup "const char *str" "size_t len" 46.Sh DESCRIPTION 47The 48.Fn strdup 49function 50allocates sufficient memory for a copy 51of the string 52.Fa str , 53does the copy, and returns a pointer to it. 54The pointer may subsequently be used as an 55argument to the function 56.Xr free 3 . 57.Pp 58If insufficient memory is available, NULL is returned and 59.Va errno 60is set to 61.Er ENOMEM . 62.Pp 63The 64.Fn strndup 65function copies at most 66.Fa len 67characters from the string 68.Fa str 69always 70.Dv NUL 71terminating the copied string. 72.Sh SEE ALSO 73.Xr free 3 , 74.Xr malloc 3 , 75.Xr wcsdup 3 76.Sh STANDARDS 77The 78.Fn strdup 79function is specified by 80.St -p1003.1-2001 . 81The 82.Fn strndup 83function is specified by 84.St -p1003.1-2008 . 85.Sh HISTORY 86The 87.Fn strdup 88function first appeared in 89.Bx 4.4 . 90The 91.Fn strndup 92function was added in 93.Fx 7.2 . 94