1 .\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk)
3 .\" %%%LICENSE_START(VERBATIM)
4 .\" Permission is granted to make and distribute verbatim copies of this
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8 .\" Permission is granted to copy and distribute modified versions of this
9 .\" manual under the conditions for verbatim copying, provided that the
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13 .\" Since the Linux kernel and libraries are constantly changing, this
14 .\" manual page may be incorrect or out-of-date. The author(s) assume no
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16 .\" the use of the information contained herein. The author(s) may not
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18 .\" which is licensed free of charge, as they might when working
21 .\" Formatted or processed versions of this manual, if unaccompanied by
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25 .\" References consulted:
26 .\" Linux libc source code
27 .\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991)
29 .\" Modified Sun Jul 25 10:41:34 1993 by Rik Faith (faith@cs.unc.edu)
30 .\" Modified Wed Oct 17 01:12:26 2001 by John Levon <moz@compsoc.man.ac.uk>
31 .TH STRDUP 3 2017-09-15 "GNU" "Linux Programmer's Manual"
33 strdup, strndup, strdupa, strndupa \- duplicate a string
36 .B #include <string.h>
38 .BI "char *strdup(const char *" s );
40 .BI "char *strndup(const char *" s ", size_t " n );
41 .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 _XOPEN_SOURCE\ >=\ 500
55 .\" || _XOPEN_SOURCE\ &&\ _XOPEN_SOURCE_EXTENDED
56 || /* Since glibc 2.12: */ _POSIX_C_SOURCE\ >=\ 200809L
57 || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
64 _POSIX_C_SOURCE\ >=\ 200809L
78 function returns a pointer to a new string which
79 is a duplicate of the string
81 Memory for the new string is
89 function is similar, but copies at most
98 bytes are copied, and a terminating null byte (\(aq\\0\(aq) is added.
105 to allocate the buffer.
106 They are available only when using the GNU
107 GCC suite, and suffer from the same limitations described in
112 function returns a pointer to the duplicated
114 It returns NULL if insufficient memory was available, with
116 set to indicate the cause of the error.
120 Insufficient memory available to allocate duplicate string.
122 For an explanation of the terms used in this section, see
128 Interface Attribute Value
135 T} Thread safety MT-Safe
139 .\" 4.3BSD-Reno, not (first) 4.3BSD.
141 conforms to SVr4, 4.3BSD, POSIX.1-2001.
143 conforms to POSIX.1-2008.