ZIP_SOURCE_FUNCTION(3) Library Functions Manual ZIP_SOURCE_FUNCTION(3)NAMEzip_source_function - create data source from function
LIBRARY
libzip (-lzip)
SYNOPSIS
#include <zip.h>
struct zip_source *
zip_source_function(struct zip *archive, zip_source_callback fn, void
*userdata);
DESCRIPTION
The function zip_source_function() creates a zip source from the user-
provided function fn, which must be of the following type:
typedef zip_int64_t (*zip_source_callback)(void *state,
void *data, zip_uint64_t len, enum zip_source_cmd cmd);
When called by the library, the first argument is the userdata argument
supplied to zip_source_function(). The next two arguments are a buffer
data of size len when data is expected to be returned, or else NULL and
0. The last argument, cmd, specifies which action the function should
perform:
ZIP_SOURCE_OPEN Prepare for reading. Return 0 on success,
-1 on error.
ZIP_SOURCE_READ Read data into the buffer data of size len.
Return the number of bytes placed into data
on success, -1 on error.
ZIP_SOURCE_CLOSE Reading is done. Return 0.
ZIP_SOURCE_STAT Get meta information for the input data.
data points to an allocated struct zip_stat,
which should be initialized using
zip_stat_init(3) and then filled in.
Information only available after the source
has been read (e.g. size) can be omitted in
an earlier call. Return sizeof(struct
zip_stat) on success, -1 on error. NOTE:
zip_source_function() may be called with
this argument even after being called with
ZIP_SOURCE_CLOSE.
ZIP_SOURCE_ERROR Get error information. data points to an
array of two ints, which should be filled
with the libzip error code and the
corresponding system error code for the
error that occurred. See zip_errors(3) for
details on the error codes. Return return(2
* sizeof(int)).
ZIP_SOURCE_FREE Clean up and free all resources. Return 0.
The library will always issue ZIP_SOURCE_OPEN before issuing
ZIP_SOURCE_READ. When it no longer wishes to read from this source, it
will issue ZIP_SOURCE_CLOSE. If the library wishes to read the data
again, it will issue ZIP_SOURCE_OPEN a second time. If the function is
unable to provide the data again, it should return -1.
ZIP_SOURCE_STAT can be issued at any time. ZIP_SOURCE_ERROR will only
be issued in response to the function returning -1. ZIP_SOURCE_FREE
will be the last command issued; if ZIP_SOURCE_OPEN was called and
succeeded, ZIP_SOURCE_CLOSE will be called before ZIP_SOURCE_FREE.
RETURN VALUES
Upon successful completion, the created source is returned. Otherwise,
NULL is returned and the error code in archive is set to indicate the
error.
ERRORSzip_source_function() fails if:
[ZIP_ER_MEMORY] Required memory could not be allocated.
SEE ALSOlibzip(3), zip_add(3), zip_replace(3), zip_source_buffer(3),
zip_source_file(3), zip_source_filep(3), zip_source_free(3),
zip_source_zip(3), zip_stat_init(3)AUTHORS
Dieter Baron <dillo@nih.at> and Thomas Klausner <tk@giga.or.at>
NiH September 22, 2013 ZIP_SOURCE_FUNCTION(3)
