noble (3) vasprintf.3.gz

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NAME

       asprintf, vasprintf - print to allocated string

LIBRARY

       Standard C library (libc, -lc)

SYNOPSIS

       #define _GNU_SOURCE         /* See feature_test_macros(7) */
       #include <stdio.h>

       int asprintf(char **restrict strp, const char *restrict fmt, ...);
       int vasprintf(char **restrict strp, const char *restrict 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).

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

VERSIONS

       The FreeBSD implementation sets strp to NULL on error.

STANDARDS

       GNU, BSD.

SEE ALSO

       free(3), malloc(3), printf(3)