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.Dd May 5, 2020 29.Dt STRDUP 3 30.Os 31.Sh NAME 32.Nm strdup , 33.Nm strndup 34.Nd save a copy of a string 35.Sh LIBRARY 36.Lb libc 37.Sh SYNOPSIS 38.In string.h 39.Ft char * 40.Fn strdup "const char *str" 41.Ft char * 42.Fn strndup "const char *str" "size_t len" 43.Sh DESCRIPTION 44The 45.Fn strdup 46function 47allocates sufficient memory for a copy 48of the string 49.Fa str , 50does the copy, and returns a pointer to it. 51The memory is allocated with 52.Xr malloc 3 53and should be released with 54.Xr free 3 55when no longer needed. 56.Pp 57The 58.Fn strndup 59function copies at most 60.Fa len 61characters from the string 62.Fa str 63always 64.Dv NUL 65terminating the copied string. 66.Sh RETURN VALUES 67If insufficient memory is available, NULL is returned and 68.Va errno 69is set to 70.Er ENOMEM . 71Otherwise, the 72.Fn strdup 73family of functions return a pointer to the copied string. 74.Sh SEE ALSO 75.Xr free 3 , 76.Xr malloc 3 , 77.Xr wcsdup 3 78.Sh STANDARDS 79The 80.Fn strdup 81function is specified by 82.St -p1003.1-2001 . 83The 84.Fn strndup 85function is specified by 86.St -p1003.1-2008 . 87.Sh HISTORY 88The 89.Fn strdup 90function first appeared in 91.Bx 4.3 Reno . 92The 93.Fn strndup 94function was added in 95.Fx 7.2 . 96