Answer:
a. If the read is successful, the number of bytes read is returned.
b. If the end of file is encountered, 0 is returned.
Explanation:
A read function is one of the functions used in computer programming. A read function is used to read an information or data that was written before into a file.
If any portion of a regular file before to the end of file has not been written and the end of file is encountered the read function will return the bytes with value 0.
If read function has read some data successfully, it returns the number of bytes it read.