zip_set_file_compression —
set compression method for file in zip
libzip (-lzip)
#include
<zip.h>
int
zip_set_file_compression(
zip_t
*archive,
zip_uint64_t
index,
zip_int32_t
comp,
zip_uint32_t
comp_flags);
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.
-
-
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
NOTE: Only the deflate and store methods can be
assumed to be universally supported.
The
comp_flags argument defines the compression
level, 1 being fastest compression and 9 highest. Allowed values are 0 (which
uses the default compression for the algorithm) and 1-9, other values are
undefined. 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).
Upon successful completion 0 is returned. Otherwise, -1 is returned and the
error information in
archive is set to
indicate the error.
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.
libzip(3),
zip_stat(3)
zip_set_file_compression() was added in
libzip 0.11.
Dieter Baron
<
dillo@nih.at>
and
Thomas Klausner
<
tk@giga.or.at>