NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | CONFORMING TO | SEE ALSO | COLOPHON
ASPRINTF(3) Linux Programmer's Manual ASPRINTF(3)
asprintf, vasprintf - print to allocated string
#define _GNU_SOURCE
#include <stdio.h>
int asprintf(char **strp, const char *fmt, ...);
int vasprintf(char **strp, const char *fmt, va_list ap);
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, 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.
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.
free(3), malloc(3), printf(3), feature_test_macros(7)
This page is part of release 3.23 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can be found
at http://www.kernel.org/doc/man-pages/.
GNU 2001-12-18 ASPRINTF(3)