Write data for the current file to the buffer.
If file is empty, len will be set to 0 and buf will be unchanged. If file has no data (s->data == 0), do nothing.
Buffer is appended with 0 byte. (zero terminated)
- Parameters:
-
| s | Pointer to the untgz_state object. |
| buf | Pointer to the pointer that will be updated with the address of the buffer with the data from the current file in archive. |
| len | Pointer to the integer that will be updated with the size of the buffer. |
- Returns:
- 0 on success, 1 if no data, -1 on error.