ARCHIVE_READ_DATA(3)	 BSD Library Functions Manual	  ARCHIVE_READ_DATA(3)

NAME

     archive_read_data archive_read_data_block, archive_read_data_skip,

     archive_read_data_into_fd — functions for reading streaming archives

LIBRARY

     Streaming Archive Library (libarchive, -larchive)

SYNOPSIS

     #include <archive.h>

     la_ssize_t

     archive_read_data(struct archive *, void *buff, size_t len);

     int

     archive_read_data_block(struct archive *, const void **buff, size_t *len,

	 off_t *offset);

     int

     archive_read_data_skip(struct archive *);

     int

     archive_read_data_into_fd(struct archive *, int fd);

DESCRIPTION

     archive_read_data()

	     Read data associated with the header just read.  Internally, this

	     is a convenience function that calls archive_read_data_block()

	     and fills any gaps with nulls so that callers see a single con‐

	     tinuous stream of data.

     archive_read_data_block()

	     Return the next available block of data for this entry.  Unlike

	     archive_read_data(), the archive_read_data_block() function

	     avoids copying data and allows you to correctly handle sparse

	     files, as supported by some archive formats.  The library guaran‐

	     tees that offsets will increase and that blocks will not overlap.

	     Note that the blocks returned from this function can be much

	     larger than the block size read from disk, due to compression and

	     internal buffer optimizations.

     archive_read_data_skip()

	     A convenience function that repeatedly calls

	     archive_read_data_block() to skip all of the data for this ar‐

	     chive entry.  Note that this function is invoked automatically by

	     archive_read_next_header2() if the previous entry was not com‐

	     pletely consumed.

     archive_read_data_into_fd()

	     A convenience function that repeatedly calls

	     archive_read_data_block() to copy the entire entry to the pro‐

	     vided file descriptor.

RETURN VALUES

     Most functions return zero on success, non-zero on error.	The possible

     return codes include: ARCHIVE_OK (the operation succeeded), ARCHIVE_WARN

     (the operation succeeded but a non-critical error was encountered),

     ARCHIVE_EOF (end-of-archive was encountered), ARCHIVE_RETRY (the opera‐

     tion failed but can be retried), and ARCHIVE_FATAL (there was a fatal

     error; the archive should be closed immediately).

     archive_read_data() returns a count of bytes actually read or zero at the

     end of the entry.	On error, a value of ARCHIVE_FATAL, ARCHIVE_WARN, or

     ARCHIVE_RETRY is returned.

ERRORS

     Detailed error codes and textual descriptions are available from the

     archive_errno() and archive_error_string() functions.

SEE ALSO

     tar(1), libarchive(3), archive_read(3), archive_read_extract(3),

     archive_read_filter(3), archive_read_format(3), archive_read_header(3),

     archive_read_open(3), archive_read_set_options(3), archive_util(3),

     tar(5)

BSD			       February 2, 2012 			   BSD