deflate.ss: Deflating (Compressing) Data
To load: (require (lib "deflate.ss"))
(gzip in-filename [out-filename]) PROCEDURE
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-ports in 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.
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 result is three values: the number of bytes read from in,
the number of bytes written to out, and a cyclic redundancy
check (CRC) value for the input.