This command, part of zlib, creates a streaming compression or decompression command, allowing greater control over the compression/decompression process. It returns the name of the stream instance command. The mode must be one of compress, decompress, deflate, inflate, gzip, gunzip. The optional level, which is only valid for compressing streams, gives the compression level from 0 (none) to 9 (max).
The returned streamInst command will support the following subcommands: