NAME

       archive_clear_error,  archive_compression,  archive_compression_name,  archive_copy_error, archive_errno,
       archive_error_string, archive_file_count, archive_filter_code, archive_filter_count, archive_filter_name,
       archive_format, archive_format_name, archive_position, archive_set_error — libarchive utility functions

LIBRARY

       Streaming Archive Library (libarchive, -larchive)

SYNOPSIS

       #include <archive.h>

       void
       archive_clear_error(struct archive *);

       int
       archive_compression(struct archive *);

       const char *
       archive_compression_name(struct archive *);

       void
       archive_copy_error(struct archive *, struct archive *);

       int
       archive_errno(struct archive *);

       const char *
       archive_error_string(struct archive *);

       int
       archive_file_count(struct archive *);

       int
       archive_filter_code(struct archive *, int);

       int
       archive_filter_count(struct archive *, int);

       const char *
       archive_filter_name(struct archive *, int);

       int
       archive_format(struct archive *);

       const char *
       archive_format_name(struct archive *);

       int64_t
       archive_position(struct archive *, int);

       void
       archive_set_error(struct archive *, int error_code, const char *fmt, ...);

DESCRIPTION

       These functions provide access to various information  about  the  struct  archive  object  used  in  the
       libarchive(3) library.
       archive_clear_error()
               Clears any error information left over from a previous call.  Not generally used in client code.
       archive_compression()
               Synonym for archive_filter_code(a,(0)).
       archive_compression_name()
               Synonym for archive_filter_name(a,(0)).
       archive_copy_error()
               Copies error information from one archive to another.
       archive_errno()
               Returns  a  numeric  error  code  (see  errno(2)) indicating the reason for the most recent error
               return.  Note that this can not be reliably used to detect whether an  error  has  occurred.   It
               should be used only after another libarchive function has returned an error status.
       archive_error_string()
               Returns  a  textual  error  message suitable for display.  The error message here is usually more
               specific than that obtained from passing the result of archive_errno() to strerror(3).
       archive_file_count()
               Returns a count of the  number  of  files  processed  by  this  archive  object.   The  count  is
               incremented by calls to archive_write_header(3) or archive_read_next_header(3).
       archive_filter_code()
               Returns  a numeric code identifying the indicated filter.  See archive_filter_count() for details
               of the numbering.
       archive_filter_count()
               Returns the number of filters in the current pipeline.  For read archive handles,  these  filters
               are  added  automatically  by  the  automatic format detection.  For write archive handles, these
               filters are added by calls to the various archive_write_add_filter_XXX() functions.   Filters  in
               the resulting pipeline are numbered so that filter 0 is the filter closest to the format handler.
               As  a  convenience,  functions  that  expect  a filter number will accept -1 as a synonym for the
               highest-numbered filter.

               For example, when reading a uuencoded gzipped tar archive, there are three filters: filter  0  is
               the  gunzip filter, filter 1 is the uudecode filter, and filter 2 is the pseudo-filter that wraps
               the archive read functions.  In this case, requesting archive_position(a,(-1)) would be a synonym
               for archive_position(a,(2)) which would return the  number  of  bytes  currently  read  from  the
               archive,  while  archive_position(a,(1))  would  return the number of bytes after uudecoding, and
               archive_position(a,(0)) would return the number of bytes after decompression.
       archive_filter_name()
               Returns a textual name identifying the indicated filter.  See archive_filter_count() for  details
               of the numbering.
       archive_format()
               Returns  a numeric code indicating the format of the current archive entry.  This value is set by
               a successful call to archive_read_next_header().  Note that it is common for this value to change
               from entry to entry.  For example, a tar archive might have several entries that utilize GNU  tar
               extensions and several entries that do not.  These entries will have different format codes.
       archive_format_name()
               A textual description of the format of the current entry.
       archive_position()
               Returns  the  number  of  bytes  read  from  or  written to the indicated filter.  In particular,
               archive_position(a,(0)) returns the number of bytes read or written by the format handler,  while
               archive_position(a,(-1))  returns  the  number  of  bytes  read  or  written to the archive.  See
               archive_filter_count() for details of the numbering here.
       archive_set_error()
               Sets the numeric error code and error description that will be returned  by  archive_errno()  and
               archive_error_string().  This function should be used within I/O callbacks to set system-specific
               error  codes  and  error  descriptions.   This  function  accepts a printf-like format string and
               arguments.  However, you should be careful to use only the following  printf  format  specifiers:
               “%c”, “%d”, “%jd”, “%jo”, “%ju”, “%jx”, “%ld”, “%lo”, “%lu”, “%lx”, “%o”, “%u”, “%s”, “%x”, “%%”.
               Field-width  specifiers  and  other printf features are not uniformly supported and should not be
               used.

SEE ALSO

       archive_read(3), archive_write(3), libarchive(3), printf(3)

HISTORY

       The libarchive library first appeared in FreeBSD 5.3.

AUTHORS

       The libarchive library was written by Tim Kientzle <kientzle@acm.org>.

Debian                                          February 2, 2012                                 ARCHIVE_UTIL(3)