.TH LIBSIMPLE_ALIGNED_STRNDUP 3 libsimple
.SH NAME
libsimple_aligned_strndup, libsimple_aligned_strndupa \- duplicate a string

.SH SYNOPSIS
.nf
#include <libsimple.h>

char *libsimple_aligned_strndupa(const char *\fIs\fP, size_t \fIalignment\fP, size_t \fIn\fP);
char *libsimple_aligned_strndup(const char *\fIs\fP, size_t \fIalignment\fP, size_t \fIn\fP);
char *libsimple_enaligned_strndup(int \fIstatus\fP, const char *\fIs\fP, size_t \fIalignment\fP, size_t \fIn\fP);
inline char *libsimple_ealigned_strndup(const char *\fIs\fP, size_t \fIalignment\fP, size_t \fIn\fP);

#ifndef aligned_strndupa
# define aligned_strndupa libsimple_aligned_strndupa
#endif
#ifndef aligned_strndup
# define aligned_strndup libsimple_aligned_strndup
#endif
#ifndef enaligned_strndup
# define enaligned_strndup libsimple_enaligned_strndup
#endif
#ifndef ealigned_strndup
# define ealigned_strndup libsimple_ealigned_strndup
#endif
.fi
.PP
Link with
.IR \-lsimple .

.SH DESCRIPTION
The
.BR libsimple_aligned_strndup ()
function allocates memory with the alignment
specified in the
.I alignment
parameter and copies the string
.I s
into the new allocation, up to the
.IR n th
byte. A NUL byte will always be written
to the end of the new string.
.PP
The
.BR libsimple_enaligned_strndup ()
and
.BR libsimple_ealigned_strndup ()
functions are versions of the
.BR libsimple_aligned_strndup ()
function that call the
.BR libsimple_enprintf (3)
function on failure, causing the process to print
an error message and exit. See
.BR libsimple_enprintf (3)
for more information.
.PP
The
.BR libsimple_strndupa ()
function is implemented as a macro and is a version
of the
.BR libsimple_strndup ()
function that uses allocates the memory on the stack
rather than on the heap, causing the return pointer
to become invalid when the calling function returns.
It is only available when compling with GCC or Clang.

.SH RETURN VALUE
Upon successful completion, the
.BR libsimple_aligned_strndupa (),
.BR libsimple_aligned_strndup (),
.BR libsimple_enaligned_strndup (),
and
.BR libsimple_ealigned_strndup ()
functions return a non-null pointer, on failure the
.BR libsimple_aligned_strndup ()
function returns
.B NULL
and set
.I errno
to indicate the error, and the
.BR libsimple_enaligned_strndup (),
and
.BR libsimple_ealigned_strndup ()
functions exit the process. The
.BR libsimple_aligned_strndupa ()
function cannot fail, however the kernel
can kill the thread, and possibly the process, with a
.B SIGSEGV
signal if the memory cannot be allocated.
.PP
The returned pointer should be deallocated when it
is no longer needed, except for the pointer returned
by the
.BR libsimple_aligned_strndupa ()
function, it is automatically deallocated when the
calling function returns.

.SH ERRORS
The
.BR libsimple_aligned_strndup ()
function may fail for any reason specified for the
.BR aligned_alloc (3)
function.

.SH ATTRIBUTES
For an explanation of the terms used in this section, see
.BR attributes (7).
.TS
allbox;
lb lb lb
l l l.
Interface	Attribute	Value
T{
.BR libsimple_aligned_strndupa (),
.br
.BR libsimple_aligned_strndup (),
.br
.BR libsimple_enaligned_strndup (),
.br
.BR libsimple_ealigned_strndup (),
T}	Thread safety	MT-Safe
T{
.BR libsimple_aligned_strndupa (),
.br
.BR libsimple_aligned_strndup (),
.br
.BR libsimple_enaligned_strndup (),
.br
.BR libsimple_ealigned_strndup (),
T}	Async-signal safety	AS-Safe
T{
.BR libsimple_aligned_strndupa (),
.br
.BR libsimple_aligned_strndup (),
.br
.BR libsimple_enaligned_strndup (),
.br
.BR libsimple_ealigned_strndup (),
T}	Async-cancel safety	AC-Safe
.TE

.SH EXAMPLES
None.

.SH APPLICATION USAGE
None.

.SH RATIONALE
None.

.SH FUTURE DIRECTIONS
None.

.SH NOTES
None.

.SH HISTORY
libsimple 1.2

.SH BUGS
None.

.SH SEE ALSO
.BR libsimple_aligned_strdup (3),
.BR libsimple_aligned_memdup (3),
.BR libsimple_aligned_wcsdup (3),
.BR libsimple_aligned_wcsndup (3),
.BR libsimple_aligned_wmemdup (3),
.BR strndup (3)