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 May 5, 2020 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 memory is allocated with 55.Xr malloc 3 56and should be released with 57.Xr free 3 58when no longer needed. 59.Pp 60The 61.Fn strndup 62function copies at most 63.Fa len 64characters from the string 65.Fa str 66always 67.Dv NUL 68terminating the copied string. 69.Sh RETURN VALUES 70If insufficient memory is available, NULL is returned and 71.Va errno 72is set to 73.Er ENOMEM . 74Otherwise, the 75.Fn strdup 76family of functions return a pointer to the copied string. 77.Sh SEE ALSO 78.Xr free 3 , 79.Xr malloc 3 , 80.Xr wcsdup 3 81.Sh STANDARDS 82The 83.Fn strdup 84function is specified by 85.St -p1003.1-2001 . 86The 87.Fn strndup 88function is specified by 89.St -p1003.1-2008 . 90.Sh HISTORY 91The 92.Fn strdup 93function first appeared in 94.Bx 4.3 Reno . 95The 96.Fn strndup 97function was added in 98.Fx 7.2 . 99