1 .\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk)
3 .\" Permission is granted to make and distribute verbatim copies of this
4 .\" manual provided the copyright notice and this permission notice are
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7 .\" Permission is granted to copy and distribute modified versions of this
8 .\" manual under the conditions for verbatim copying, provided that the
9 .\" entire resulting derived work is distributed under the terms of a
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12 .\" Since the Linux kernel and libraries are constantly changing, this
13 .\" manual page may be incorrect or out-of-date. The author(s) assume no
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15 .\" the use of the information contained herein. The author(s) may not
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17 .\" which is licensed free of charge, as they might when working
20 .\" Formatted or processed versions of this manual, if unaccompanied by
21 .\" the source, must acknowledge the copyright and authors of this work.
23 .\" References consulted:
24 .\" Linux libc source code
25 .\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991)
27 .\" Modified Sun Jul 25 10:41:34 1993 by Rik Faith (faith@cs.unc.edu)
28 .\" Modified Wed Oct 17 01:12:26 2001 by John Levon <moz@compsoc.man.ac.uk>
29 .TH STRDUP 3 2010-09-26 "GNU" "Linux Programmer's Manual"
31 strdup, strndup, strdupa, strndupa \- duplicate a string
34 .B #include <string.h>
36 .BI "char *strdup(const char *" s );
38 .BI "char *strndup(const char *" s ", size_t " n );
40 .BI "char *strdupa(const char *" s );
42 .BI "char *strndupa(const char *" s ", size_t " n );
46 Feature Test Macro Requirements for glibc (see
47 .BR feature_test_macros (7)):
54 _SVID_SOURCE || _BSD_SOURCE || _XOPEN_SOURCE\ >=\ 500 ||
55 _XOPEN_SOURCE\ &&\ _XOPEN_SOURCE_EXTENDED
57 || /* Since glibc 2.12: */ _POSIX_C_SOURCE\ >=\ 200809L
64 POSIX_C_SOURCE\ >=\ 200809L || _XOPEN_SOURCE\ >=\ 700
78 function returns a pointer to a new string which
79 is a duplicate of the string \fIs\fP.
80 Memory for the new string is
88 function is similar, but only copies at most
90 If \fIs\fP is longer than \fIn\fP, only \fIn\fP
91 characters are copied, and a terminating null byte (\(aq\\0\(aq) is added.
98 to allocate the buffer.
99 They are only available when using the GNU
100 GCC suite, and suffer from the same limitations described in
105 function returns a pointer to the duplicated
106 string, or NULL if insufficient memory was available.
110 Insufficient memory available to allocate duplicate string.
112 .\" 4.3BSD-Reno, not (first) 4.3BSD.
114 conforms to SVr4, 4.3BSD, POSIX.1-2001.