In gzip library, what's the difference between 'uncompress' and 'gzopen'?

There are some functions to decompress in zlib library (zlib version 1.2.3)

I want to decompress my source zip (.gz) file using uncompress function. It is not working (error code -3) but gzopen is. It is still not working when I input payload pointer (passing gzip he开发者_运维百科ader) to uncompress.

So the question is:

• What's the valid arguments for uncompress function?
• If it needs different format, how can I make it?

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You have to use some poorly documented features of the zlib library. See my answer to this question for more information: How can I decompress a gzip stream with zlib?