Compresses data to the same format as the GNU gzip utility,
writing the compressed data directly to a file. The in-filename
argument is the name of the file to compress. The default output file
name is in-filename with .gz appended. If the file named
by out-filename exists, it will be overwritten. The return
value is void.
(gzip-through-portsin out orig-filename timestamp) PROCEDURE
Reads the port in for data and compresses it to out,
outputting the same format as the GNU gzip utility. The
orig-filename string is embedded in this output;
orig-filename can be #f to omit the filename from the
compressed stream. The timestamp number is also embedded in the
output stream, as the modification date of the original file (in Unix
seconds, as file-or-directory-modify-seconds would report under
Unix). The return value is void.
(deflatein out) PROCEDURE
Writes pkzip-format ``deflated'' data to the port out,
compressing data from the port in. The data in a file created
by gzip uses this format (preceded with some header
information). The return value is void.