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 are undefined.

ATTRIBUTES

       For an explanation of the terms used in this section, see attributes(7).

       ┌────────────────────────┬───────────────┬────────────────┐
       │Interface               │ Attribute     │ Value          │
       ├────────────────────────┼───────────────┼────────────────┤
       │asprintf(), vasprintf() │ Thread safety │ MT-Safe locale │
       └────────────────────────┴───────────────┴────────────────┘

CONFORMING TO

       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

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       information  about  reporting  bugs,  and  the  latest  version  of  this   page,   can   be   found   at
       https://www.kernel.org/doc/man-pages/.