NAME¶
asprintf, vasprintf - print to allocated string
SYNOPSIS¶
#define _GNU_SOURCE /* See
feature_test_macros(7) */
#include <stdio.h>
int asprintf(char **strp, const char *fmt,
...);
int vasprintf(char **strp, const char *fmt,
va_list ap);
DESCRIPTION¶
The functions
asprintf() and
vasprintf() are analogs of
sprintf(3) and
vsprintf(3), except that they allocate a string
large enough to hold the output including the terminating null byte ('\0'),
and return a pointer to it via the first argument. This pointer should be
passed to
free(3) to release the allocated storage when it is no longer
needed.
RETURN VALUE¶
When successful, these functions return the number of bytes printed, just like
sprintf(3). If memory allocation wasn't possible, or some other error
occurs, these functions will return -1, and the contents of
strp is
undefined.
These functions are GNU extensions, not in C or POSIX. They are also available
under *BSD. The FreeBSD implementation sets
strp to NULL on error.
SEE ALSO¶
free(3),
malloc(3),
printf(3)
COLOPHON¶
This page is part of release 3.74 of the Linux
man-pages project. A
description of the project, information about reporting bugs, and the latest
version of this page, can be found at
http://www.kernel.org/doc/man-pages/.
