1ARCHIVE_UTIL(3) BSD Library Functions Manual ARCHIVE_UTIL(3)
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4 archive_clear_error, archive_compression, archive_compression_name,
5 archive_copy_error, archive_errno, archive_error_string,
6 archive_file_count, archive_filter_code, archive_filter_count,
7 archive_filter_name, archive_format, archive_format_name,
8 archive_position, archive_set_error — libarchive utility functions
9
11 Streaming Archive Library (libarchive, -larchive)
12
14 #include <archive.h>
15 void
17 archive_clear_error(struct archive *);
18 int
20 archive_compression(struct archive *);
21 const char *
23 archive_compression_name(struct archive *);
24 void
26 archive_copy_error(struct archive *, struct archive *);
27 int
29 archive_errno(struct archive *);
30 const char *
32 archive_error_string(struct archive *);
33 int
35 archive_file_count(struct archive *);
36 int
38 archive_filter_code(struct archive *, int);
39 int
41 archive_filter_count(struct archive *, int);
42 const char *
44 archive_filter_name(struct archive *, int);
45 int
47 archive_format(struct archive *);
48 const char *
50 archive_format_name(struct archive *);
51 int64_t
53 archive_position(struct archive *, int);
54 void
56 archive_set_error(struct archive *, int error_code, const char *fmt,
57 ...);
58
60 These functions provide access to various information about the struct
61 archive object used in the libarchive(3) library.
62 archive_clear_error()
63 Clears any error information left over from a previous call. Not
64 generally used in client code.
65 archive_compression()
66 Synonym for archive_filter_code(a, 0).
67 archive_compression_name()
68 Synonym for archive_filter_name(a, 0).
69 archive_copy_error()
70 Copies error information from one archive to another.
71 archive_errno()
72 Returns a numeric error code (see errno(2)) indicating the reason
73 for the most recent error return. Note that this can not be
74 reliably used to detect whether an error has occurred. It should
75 be used only after another libarchive function has returned an
76 error status.
77 archive_error_string()
78 Returns a textual error message suitable for display. The error
79 message here is usually more specific than that obtained from
80 passing the result of archive_errno() to strerror(3).
81 archive_file_count()
82 Returns a count of the number of files processed by this archive
83 object. The count is incremented by calls to
84 archive_write_header(3) or archive_read_next_header(3).
85 archive_filter_code()
86 Returns a numeric code identifying the indicated filter. See
87 archive_filter_count() for details of the numbering.
88 archive_filter_count()
89 Returns the number of filters in the current pipeline. For read
90 archive handles, these filters are added automatically by the
91 automatic format detection. For write archive handles, these
92 filters are added by calls to the various
93 archive_write_add_filter_XXX() functions. Filters in the result‐
94 ing pipeline are numbered so that filter 0 is the filter closest
95 to the format handler. As a convenience, functions that expect a
96 filter number will accept -1 as a synonym for the highest-num‐
97 bered filter.
98 For example, when reading a uuencoded gzipped tar archive, there
100 are three filters: filter 0 is the gunzip filter, filter 1 is the
101 uudecode filter, and filter 2 is the pseudo-filter that wraps the
102 archive read functions. In this case, requesting
103 archive_position(a, -1) would be a synonym for
104 archive_position(a, 2) which would return the number of bytes
105 currently read from the archive, while archive_position(a, 1)
106 would return the number of bytes after uudecoding, and
107 archive_position(a, 0) would return the number of bytes after
108 decompression.
109 archive_filter_name()
110 Returns a textual name identifying the indicated filter. See
111 archive_filter_count() for details of the numbering.
112 archive_format()
113 Returns a numeric code indicating the format of the current ar‐
114 chive entry. This value is set by a successful call to
115 archive_read_next_header(). Note that it is common for this
116 value to change from entry to entry. For example, a tar archive
117 might have several entries that utilize GNU tar extensions and
118 several entries that do not. These entries will have different
119 format codes.
120 archive_format_name()
121 A textual description of the format of the current entry.
122 archive_position()
123 Returns the number of bytes read from or written to the indicated
124 filter. In particular, archive_position(a, 0) returns the number
125 of bytes read or written by the format handler, while
126 archive_position(a, -1) returns the number of bytes read or writ‐
127 ten to the archive. See archive_filter_count() for details of
128 the numbering here.
129 archive_set_error()
130 Sets the numeric error code and error description that will be
131 returned by archive_errno() and archive_error_string(). This
132 function should be used within I/O callbacks to set system-spe‐
133 cific error codes and error descriptions. This function accepts
134 a printf-like format string and arguments. However, you should
135 be careful to use only the following printf format specifiers:
136 “%c”, “%d”, “%jd”, “%jo”, “%ju”, “%jx”, “%ld”, “%lo”, “%lu”,
137 “%lx”, “%o”, “%u”, “%s”, “%x”, “%%”. Field-width specifiers and
138 other printf features are not uniformly supported and should not
139 be used.
140
142 archive_read(3), archive_write(3), libarchive(3), printf(3)
143
145 The libarchive library first appeared in FreeBSD 5.3.
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148 The libarchive library was written by Tim Kientzle <kientzle@acm.org>.
149BSD February 2, 2012 BSD