vasprintf()
Write formatted output into an allocated string (varargs)
Synopsis:
#include <stdio.h>
#include <stdarg.h>
int vasprintf( char **strp,
const char *format,
va_list arg );
Arguments:
- strp
- A pointer to a location where the function can store a pointer to the allocated string.
- format
- A string that specifies the format of the output. The formatting string determines what additional arguments you need to provide. For more information, see printf().
- arg
- A variable-argument list of the additional arguments, which you must have initialized with the va_start() macro.
Library:
libc
Use the -l c option to qcc to link against this library. This library is usually included automatically.
Description:
The vasprintf() function formats data under control of the
format control string.
It's a varargs
version of
asprintf()
and is similar to
sprintf(),
except that vasprintf() allocates a string for the formatted output.
A null character is placed at the end of the generated character string.
If vasprintf() is successful, it
sets *strp to point to the string.
You should call free() to free the string when you're finished with it.
Returns:
The number of characters written into the string, not including the terminating null character, or a negative value if an output error occurred (errno is set, and *strp is left unchanged). An error can occur while converting a value for output.
Errors:
- EOVERFLOW
- An attempt was made to write a number of bytes that exceeds the allowable limit.
Classification:
| Safety: | |
|---|---|
| Cancellation point | No |
| Signal handler | No |
| Thread | Yes |