The file/gzip library provides utilities to create archive files in gzip format, or simply to compress data using the pkzip “deflate” method.

Compresses data to the same format as the gzip utility, writing the compressed data directly to a file. The in-file argument is the name of the file to compress. If the file named by out-file exists, it will be overwritten.

Reads the port in for data and compresses it to out, outputting the same format as the 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).

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 header information).