ZIP_SET_FILE_COMPRESSION(3)                           Library Functions Manual

NAME
     zip_set_file_compression - set compression method for file in zip

LIBRARY
     libzip (-lzip)

SYNOPSIS
     #include <zip.h>

     int
     zip_set_file_compression(zip_t *archive, zip_uint64_t index,
         zip_int32_t comp, zip_uint32_t comp_flags);

DESCRIPTION
     The 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:

     ZIP_CM_DEFAULT     default compression; currently the same as
                        ZIP_CM_DEFLATE, but flags are ignored.

     ZIP_CM_STORE       Store the file uncompressed.

     ZIP_CM_BZIP2       Compress the file using the bzip2(1) algorithm.

     ZIP_CM_DEFLATE     Deflate the file with the zlib(3) algorithm and
                        default options.

     ZIP_CM_XZ          Use the xz(1) algorithm for compression

     ZIP_CM_ZSTD        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_BZIP, ZIP_CM_DEFLATE, and ZIP_CM_XZ 1 is the fastest compression
     and 9 the best, 0 chooses the default.  For ZIP_CM_ZSTD possible values
     are ZSTD_minCLevel(3) to ZSTD_maxCLevel(3); negative values must be cast
     to zip_uint32_t.

     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).

RETURN VALUES
     Upon successful completion 0 is returned.  Otherwise, -1 is returned and
     the error information in archive is set to indicate the error.

ERRORS
     zip_set_file_compression() fails if:

     [ZIP_ER_COMPNOTSUPP]
                        Unsupported compression method requested.

     [ZIP_ER_INVAL]     index is not a valid file index in archive, or the
                        argument combination is invalid.

     [ZIP_ER_RDONLY]    Read-only zip file, no changes allowed.

SEE ALSO
     libzip(3), zip_compression_method_supported(3), zip_stat(3)

HISTORY
     zip_set_file_compression() was added in libzip 0.11.

AUTHORS
     Dieter Baron <dillo@nih.at> and Thomas Klausner <tk@giga.or.at>

Linux 6.7.4-arch1-1            February 2, 2023            Linux 6.7.4-arch1-1