110 lines
3 KiB
Groff
110 lines
3 KiB
Groff
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.\" Copyright (c) 1990, 1991, 1993
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.\" The Regents of the University of California. All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\" 3. Neither the name of the University nor the names of its contributors
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.\" may be used to endorse or promote products derived from this software
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.\" without specific prior written permission.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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.\"
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.\" from: @(#)strdup.3 8.1 (Berkeley) 6/9/93
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.\" $NetBSD: strdup.3,v 1.18 2009/01/29 10:15:39 wiz Exp $
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.\"
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.Dd January 28, 2009
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.Dt STRDUP 3
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.Os
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.Sh NAME
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.Nm strdup ,
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.Nm strndup
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.Nd save a copy of a string
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.Sh LIBRARY
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.Lb libc
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.Sh SYNOPSIS
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.In string.h
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.Ft char *
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.Fn strdup "const char *str"
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.Ft char *
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.Fn strndup "const char *str" "size_t len"
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.Sh DESCRIPTION
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The
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.Fn strdup
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function
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allocates sufficient memory for a copy
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of the string
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.Fa str ,
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does the copy, and returns a pointer to it.
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The pointer may subsequently be used as an
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argument to the function
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.Xr free 3 .
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.Pp
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If insufficient memory is available,
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.Dv NULL
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is returned.
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.Pp
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The
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.Fn strndup
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function copies at most
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.Fa len
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characters from the string
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.Fa str
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always
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.Dv NUL
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terminating the copied string.
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.Sh EXAMPLES
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The following will point
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.Va p
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to an allocated area of memory containing the nul-terminated string
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.Qq foobar :
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.Bd -literal -offset indent
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char *p;
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if ((p = strdup("foobar")) == NULL) {
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fprintf(stderr, "Out of memory.\en");
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exit(1);
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}
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.Ed
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.Sh ERRORS
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The
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.Fn strdup
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function may fail and set the external variable
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.Va errno
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for any of the errors specified for the library function
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.Xr malloc 3 .
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.Sh SEE ALSO
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.Xr free 3 ,
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.Xr malloc 3 ,
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.Xr strcpy 3 ,
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.Xr strlen 3
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.Sh STANDARDS
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The
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.Fn strdup
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function conforms to
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.St -p1003.1-2001 .
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.Sh HISTORY
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The
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.Fn strdup
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function first appeared in
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.Bx 4.4 .
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The
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.Fn strndup
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function was added in
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.Nx 4.0 .
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