| .\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk) |
| .\" |
| .\" Permission is granted to make and distribute verbatim copies of this |
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| .\" Permission is granted to copy and distribute modified versions of this |
| .\" manual under the conditions for verbatim copying, provided that the |
| .\" entire resulting derived work is distributed under the terms of a |
| .\" permission notice identical to this one. |
| .\" |
| .\" Since the Linux kernel and libraries are constantly changing, this |
| .\" manual page may be incorrect or out-of-date. The author(s) assume no |
| .\" responsibility for errors or omissions, or for damages resulting from |
| .\" the use of the information contained herein. The author(s) may not |
| .\" have taken the same level of care in the production of this manual, |
| .\" which is licensed free of charge, as they might when working |
| .\" professionally. |
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| .\" Formatted or processed versions of this manual, if unaccompanied by |
| .\" the source, must acknowledge the copyright and authors of this work. |
| .\" |
| .\" References consulted: |
| .\" Linux libc source code |
| .\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991) |
| .\" 386BSD man pages |
| .\" Modified Sun Jul 25 10:41:34 1993 by Rik Faith (faith@cs.unc.edu) |
| .\" Modified Wed Oct 17 01:12:26 2001 by John Levon <moz@compsoc.man.ac.uk> |
| .TH STRDUP 3 1993-04-12 "GNU" "Linux Programmer's Manual" |
| .SH NAME |
| strdup, strndup, strdupa, strndupa \- duplicate a string |
| .SH SYNOPSIS |
| .nf |
| .B #include <string.h> |
| .sp |
| .BI "char *strdup(const char *" s ); |
| .sp |
| .B #define _GNU_SOURCE |
| .br |
| .B #include <string.h> |
| .sp |
| .BI "char *strndup(const char *" s ", size_t " n ); |
| .br |
| .BI "char *strdupa(const char *" s ); |
| .br |
| .BI "char *strndupa(const char *" s ", size_t " n ); |
| .sp |
| .fi |
| .SH DESCRIPTION |
| The \fBstrdup\fP() function returns a pointer to a new string which |
| is a duplicate of the string \fIs\fP. Memory for the new string is |
| obtained with \fBmalloc\fP(3), and can be freed with \fBfree\fP(3). |
| |
| The \fBstrndup\fP() function is similar, but only copies at most |
| \fIn\fP characters. If \fIs\fP is longer than \fIn\fP, only \fIn\fP |
| characters are copied, and a terminating null byte ('\\0') is added. |
| |
| \fBstrdupa\fP() and \fBstrndupa\fP() are similar, but use \fBalloca(3)\fP |
| to allocate the buffer. They are only available when using the GNU |
| GCC suite, and suffer from the same limitations described in \fBalloca(3)\fP. |
| |
| .SH "RETURN VALUE" |
| The \fBstrdup\fP() function returns a pointer to the duplicated |
| string, or NULL if insufficient memory was available. |
| .SH ERRORS |
| .TP |
| .B ENOMEM |
| Insufficient memory available to allocate duplicate string. |
| .SH "CONFORMING TO" |
| .\" 4.3BSD-Reno, not (first) 4.3BSD. |
| SVID 3, 4.3BSD. |
| \fBstrndup\fP(), \fBstrdupa\fP(), and \fBstrndupa\fP() are GNU extensions. |
| .SH "SEE ALSO" |
| .BR alloca (3), |
| .BR calloc (3), |
| .BR free (3), |
| .BR malloc (3), |
| .BR realloc (3) |