RETURN VALUE
These functions return the number of input items assigned, which can be
fewer than provided for, or even zero, in the event of a matching fail-
ure. Zero indicates that, while there was input available, no conver-
sions were assigned; typically this is due to an invalid input charac-
ter, such as an alphabetic character for a `%d' conversion. The value
EOF is returned if an input failure occurs before any conversion such
as an end-of-file occurs. If an error or end-of-file occurs after con-
version has begun, the number of conversions which were successfully
completed is returned.