case.
gzread returns the number of uncompressed bytes actually read, less than
- len for end of file, or -1 for error.
+ len for end of file, or -1 for error. If len is too large to fit in an int,
+ then nothing is read, -1 is returned, and the error state is set to
+ Z_STREAM_ERROR.
+*/
+
+ZEXTERN z_size_t ZEXPORT gzfread OF((voidp buf, z_size_t size, z_size_t nitems,
+ gzFile file));
+/*
+ Read up to nitems items of size size from file to buf, otherwise operating
+ as gzread() does. This duplicates the interface of stdio's fread(), with
+ size_t request and return types. If the library defines size_t, then
+ z_size_t is identical to size_t. If not, then z_size_t is an unsigned
+ integer type that can contain a pointer.
+
+ gzfread() returns the number of full items read of size size, or zero if
+ the end of the file was reached and a full item could not be read, or if
+ there was an error. gzerror() must be consulted if zero is returned in
+ order to determine if there was an error. If the multiplication of size and
+ nitems overflows, i.e. the product does not fit in a z_size_t, then nothing
+ is read, zero is returned, and the error state is set to Z_STREAM_ERROR.
+
+ In the event that the end of file is reached and only a partial item is
+ available at the end, i.e. the remaining uncompressed data length is not a
+ multiple of size, then the final partial item is nevetheless read into buf
+ and the end-of-file flag is set. The length of the partial item read is not
+ provided, but could be inferred from the result of gztell(). This behavior
+ is the same as the behavior of fread() implementations in common libraries,
+ but it prevents the direct use of gzfread() to read a concurrently written
+ file, reseting and retrying on end-of-file, when size is not 1.
*/
ZEXTERN int ZEXPORT gzwrite OF((gzFile file,