zip_source_file(3) Library Functions Manual zip_source_file(3)
NAME
zip_source_file, zip_source_file_create - create data source from a file
LIBRARY
libzip (-lzip)
SYNOPSIS
#include <zip.h>
zip_source_t *
zip_source_file(zip_t *archive, const char *fname, zip_uint64_t start,
zip_int64_t len);
zip_source_t *
zip_source_file_create(const char *fname, zip_uint64_t start,
zip_int64_t len, zip_error_t *error);
DESCRIPTION
The functions zip_source_file() and zip_source_file_create() create a zip
source from a file. They open fname and read len bytes from offset start
from it.
When passing ZIP_LENGTH_TO_END (or -1, which is deprecated) as len,
zip_source_file determines the file size when it is called and uses that
as the expected file size. If the file size grows between creating and
reading from the source, the additional data is ignored. If the file
shrinks, libzip treats it as an error (ZIP_ER_DATA_LENGTH).
When passing ZIP_LENGTH_UNCHECKED as len, zip_source_file assumes the
file's size is unknown. Reading from the source returns as much data as
is there at that time (usually when calling zip_close(3)).
libzip can do various optimizations if the size of a source is known when
it's created, so ZIP_LENGTH_TO_END is preferable. If you deal with files
that are likely to change while you are processing them, you can use the
less efficient ZIP_LENGTH_UNCHECKED.
If the file supports seek, the source can be used to open a zip archive
from.
The file is opened and read when the data from the source is used,
usually by zip_close() or zip_open_from_source().
RETURN VALUES
Upon successful completion, the created source is returned. Otherwise,
NULL is returned and the error code in archive or error is set to
indicate the error.
ERRORS
zip_source_file() and zip_source_file_create() fail if:
[ZIP_ER_INVAL] fname, start, or len are invalid.
[ZIP_ER_MEMORY] Required memory could not be allocated.
[ZIP_ER_OPEN] Opening fname failed.
SEE ALSO
libzip(3), zip_file_add(3), zip_file_replace(3), zip_source(3)
HISTORY
zip_source_file() and zip_source_file_create() were added in libzip 1.0.
ZIP_LENGTH_TO_END and ZIP_LENGTH_UNCHECKED were added in libzip 1.10.1.
AUTHORS
Dieter Baron <dillo@nih.at> and Thomas Klausner <wiz@gatalith.at>
macOS 14.7 June 30, 2023 macOS 14.7
libzip 1.11.3 - Generated Tue Mar 4 15:11:13 CST 2025