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- Update bunlded libarchive version used on Windows/Mac - Enable requested zstd support while we are at it. Closes #211
73 lines
3 KiB
Text
73 lines
3 KiB
Text
ARCHIVE_READ_DATA(3) BSD Library Functions Manual ARCHIVE_READ_DATA(3)
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NAME
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archive_read_data, archive_read_data_block, archive_read_data_skip,
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archive_read_data_into_fd — functions for reading streaming archives
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LIBRARY
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Streaming Archive Library (libarchive, -larchive)
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SYNOPSIS
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#include <archive.h>
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la_ssize_t
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archive_read_data(struct archive *, void *buff, size_t len);
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int
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archive_read_data_block(struct archive *, const void **buff, size_t *len,
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off_t *offset);
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int
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archive_read_data_skip(struct archive *);
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int
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archive_read_data_into_fd(struct archive *, int fd);
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DESCRIPTION
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archive_read_data()
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Read data associated with the header just read. Internally, this
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is a convenience function that calls archive_read_data_block()
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and fills any gaps with nulls so that callers see a single con‐
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tinuous stream of data.
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archive_read_data_block()
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Return the next available block of data for this entry. Unlike
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archive_read_data(), the archive_read_data_block() function
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avoids copying data and allows you to correctly handle sparse
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files, as supported by some archive formats. The library guaran‐
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tees that offsets will increase and that blocks will not overlap.
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Note that the blocks returned from this function can be much
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larger than the block size read from disk, due to compression and
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internal buffer optimizations.
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archive_read_data_skip()
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A convenience function that repeatedly calls
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archive_read_data_block() to skip all of the data for this ar‐
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chive entry. Note that this function is invoked automatically by
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archive_read_next_header2() if the previous entry was not com‐
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pletely consumed.
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archive_read_data_into_fd()
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A convenience function that repeatedly calls
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archive_read_data_block() to copy the entire entry to the pro‐
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vided file descriptor.
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RETURN VALUES
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Most functions return zero on success, non-zero on error. The possible
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return codes include: ARCHIVE_OK (the operation succeeded), ARCHIVE_WARN
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(the operation succeeded but a non-critical error was encountered),
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ARCHIVE_EOF (end-of-archive was encountered), ARCHIVE_RETRY (the opera‐
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tion failed but can be retried), and ARCHIVE_FATAL (there was a fatal er‐
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ror; the archive should be closed immediately).
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archive_read_data() returns a count of bytes actually read or zero at the
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end of the entry. On error, a value of ARCHIVE_FATAL, ARCHIVE_WARN, or
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ARCHIVE_RETRY is returned.
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ERRORS
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Detailed error codes and textual descriptions are available from the
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archive_errno() and archive_error_string() functions.
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SEE ALSO
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tar(1), archive_read(3), archive_read_extract(3), archive_read_filter(3),
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archive_read_format(3), archive_read_header(3), archive_read_open(3),
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archive_read_set_options(3), archive_util(3), libarchive(3), tar(5)
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BSD February 2, 2012 BSD
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