vfscanf -- convert formatted input


The scanf() family of functions shall behave as described in POSIX 1003.1-2001 (ISO/IEC 9945-2003), except as noted below.


The %s, %S and %[ conversion specifiers shall accept an option length modifier a, which shall cause a memory buffer to be allocated to hold the string converted. In such a case, the argument corresponding to the conversion specifier should be a reference to a pointer value that will receive a pointer to the allocated buffer. If there is insufficient memory to allocate a buffer, the function may set errno to ENOMEM and a conversion error results.

Note: This directly conflicts with the ISO C (1999) usage of %a as a conversion specifier for hexadecimal float values. While this conversion specifier should be supported, a format specifier such as "%aseconds" will have a different meaning on an LSB conforming system.