zip_set_file_compression() function sets the compression method for the file at position index in the zip archive to comp with the compression method specific comp_flags. The comp is the same as returned by zip_stat(3). For the comp argument, currently only the following values are supported:
- default compression; currently the same as
ZIP_CM_DEFLATE, but flags are ignored.
- Store the file uncompressed.
- Compress the file using the bzip2(1) algorithm.
- Deflate the file with the zlib(3) algorithm and default options.
- Use the xz(1) algorithm for compression
- Use the zstd(1) algorithm for compression
NOTE: Only the deflate and store methods can be assumed to be universally supported.
The comp_flags argument defines the
compression level. This value is dependent on the compression algorithm. In
general, lower numbers mean faster de/compression and higher numbers mean
slower de/compression. For
ZIP_CM_XZ 1 is the fastest compression and 9 the
best, 0 chooses the default. For
possible values are
Further compression method specific flags might be added over time.
The current compression method for a file in a zip archive can be determined using zip_stat(3).
zip_set_file_compression() fails if:
zip_set_file_compression() was added in libzip 0.11.