Initializes a string by specified symbols and provides the specified string size.
[in][out] String that should be initialized and deinitialized.
[in] String length after initialization. If length=0, it deinitializes the string, i.e. the string buffer is cleared and the buffer address is zeroed.
[in] Symbol to fill the string.
If character=0 and the length new_len>0, the buffer of the string of indicated length will be distributed and filled by zeroes. The string length will be equal to zero, because the whole buffer is filled out by string terminators.