dirfile_include (3) - Linux Manuals
dirfile_include: add a format file fragment to a dirfile
NAME
dirfile_include --- add a format file fragment to a dirfileSYNOPSIS
#include <getdata.h>- int dirfile_include(DIRFILE *dirfile, const char *include_file, int parent_fragment, unsigned long flags);
DESCRIPTION
-
/INCLUDE <include_file>
(see
dirfile-format(5)).
If a parser callback function had been specified when the dirfile was opened
using
dirfile_cbopen(3),
or added later with
dirfile_parser_callback(3),
this callback function will be called if a syntax error is encountered while
parsing the included fragment.
The flags argument should be a bitwise-or'd collection of the following flags, or zero if no flags are desired:
- GD_BIG_ENDIAN
-
Specifies that raw data on disk is stored as big-endian data (most significant
byte first). Specifying this flag along with the contradictory
GD_LITTLE_ENDIAN
will cause the library to assume that the endianness of the data is opposite to
that of the native architecture.
This flag is ignored completely if an ENDIAN directive occurs in the fragment, unless GD_FORCE_ENDIAN is also specified.
- GD_CREAT
- An empty fragment will be created, if one does not already exist. The fragment will have mode S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH (0666), modified by the caller's umask value (see umask(2)).
- GD_EXCL
- Ensure that this call creates a new fragment: when specified along with GD_CREAT, the call will fail if the file specified by include_file already exists. Behaviour of this flag is undefined if GD_CREAT is not specified. This flag suffers from all the limitations of the O_EXCL flag as indicated in open(2).
- GD_FORCE_ENCODING
- Specifies that ENCODING directives (see dirfile-format(5)) found in the fragment should be ignored. The encoding scheme specified in flags will be used instead (see below).
- GD_FORCE_ENDIAN
- Specifies that ENDIAN directives (see dirfile-format(5)) found in the fragment should be ignored. When specified with one of GD_BIG_ENDIAN or GD_LITTLE_ENDIAN, the endianness specified will be assumed. If this flag is specified with neither of those flags, the fragment will be assumed to have the endianness of the native architecture.
- GD_IGNORE_DUPS
-
If the fragment specifies more than one field with the same name, or a field
with the same name as an existing field, all but one of them will be ignored by
the parser. Without this flag, parsing would fail with the
GD_E_FORMAT
error, possibly resulting in invocation of the registered callback function.
Which of the duplicate fields is kept is not specified, nor whether an existing
field takes precedence over a new one or not. As a result, this flag is
typically only useful in the case where identical copies of a field
specification line are present.
No indication is provided to indicate whether a duplicate field has been discarded. If finer grained control is required, the caller should handle GD_E_FORMAT_DUPLICATE suberrors itself with an appropriate callback function.
- GD_IGNORE_REFS
- If the dirfile currently has a reference field (either because one was specified explicitly, or else because the first RAW field was used), /REFERENCE directives in the included fragment will be ignored. Otherwise, a /REFERENCE directive in the included fragment will replace the current reference field in the dirfile.
- GD_LITTLE_ENDIAN
-
Specifies that raw data on disk is stored as little-endian data (least
significant byte first). Specifying this flag along with the contradictory
GD_BIG_ENDIAN
will cause the library to assume that the endianness of the data is opposite to
that of the native architecture.
This flag is ignored completely if an ENDIAN directive occurs in the fragment, unless GD_FORCE_ENDIAN is also specified.
- GD_PEDANTIC
- Specifies that unrecognised lines found during the parsing of the fragment should always cause a fatal error. Without this flag, if a VERSION directive (see dirfile-format(5)) indicates that the fragment being opened conforms Standards Version newer than the version understood by the library, unrecognised lines will be silently ignored.
- GD_TRUNC
-
If
include_file
already exists, it will be truncated before opening. If the file does not
exist, this flag is ignored.
The flags argument may also be bitwise or'd with one of the following symbols indicating the default encoding scheme of the fragment. Like the endianness flags, the choice of encoding here is ignored if the encoding is specified in the fragment itself, unless GD_FORCE_ENCODED is also specified. If none of these symbols is present, GD_AUTO_ENCODED is assumed, unless the dirfile_include() call results in creation or truncation of the fragment. In that case, GD_UNENCODED is assumed. See dirfile-encoding(5) for details on dirfile encoding schemes.
- GD_AUTO_ENCODED
- Specifies that the encoding type is not known in advance, but should be detected by the GetData library. Detection is accomplished by searching for raw data files with extensions appropriate to the encoding scheme. This method will notably fail if the the library is called via putdata(3) to create a previously non-existent raw field unless a read is first successfully performed on the dirfile. Once the library has determined the encoding scheme for the first time, it remembers it for subsequent calls.
- GD_BZIP2_ENDODED
- Specifies that raw data files are compressed using the Burrows-Wheeler block sorting text compression algorithm and Huffman coding, as implemented in the bzip2 format.
- GD_GZIP_ENDODED
- Specifies that raw data files are compressed using Lempel-Ziv coding (LZ77) as implemented in the gzip format.
- GD_LZMA_ENDODED
- Specifies that raw data files are compressed using the Lempel-Ziv Markov Chain Algorithm (LZMA) as implemented in the xz container format.
- GD_SLIM_ENCODED
- Specifies that raw data files are compressed using the slimlib library.
- GD_TEXT_ENCODED
- Specifies that raw data files are encoded as text files containing one data sample per line.
- GD_UNENCODED
-
Specifies that raw data files are not encoded, but written verbatim to disk.
RETURN VALUE
On success, dirfile_include() returns the format file index of the newly added fragment. On error, -1 is returned and the dirfile error is set to a non-zero error value. Possible error values are:- GD_E_ACCMODE
- The supplied dirfile was opened in read-only mode.
- GD_E_ALLOC
- The library was unable to allocate memory.
- GD_E_BAD_DIRFILE
- The supplied dirfile was invalid.
- GD_E_BAD_INDEX
- The supplied parent fragment index was out of range.
- GD_E_BAD_REFERENCE
- The reference field specified by a /REFERENCE directive in the fragment (see dirfile-format(5)) was not found, or was not a RAW field.
- GD_E_CALLBACK
- The registered callback function returned an unrecognised response.
- GD_E_FORMAT
- A syntax error occurred in the fragment.
- GD_E_INTERNAL_ERROR
- An internal error occurred in the library while trying to perform the task. This indicates a bug in the library. Please report the incident to the maintainer.
- GD_E_OPEN_INCLUDE
- The fragment could not be opened or created.
- GD_E_PROTECTED
- The metadata of the parent fragment was protected from change.
- GD_E_REFERENCE
- The included fragment contained a /REFERENCE directive which referred to a non-existent field, or a field that was not of type RAW. In this case, the included fragment will still be added to the dirfile, but the /REFERENCE directive will be ignored. See also the BUGS section below. The dirfile error may be retrieved by calling get_error(3). A descriptive error string for the last error encountered can be obtained from a call to get_error_string(3). When finished with it, the DIRFILE object may be deallocated with a call to dirfile_close(3), even if the open failed.
BUGS
If this function fails with the error GD_E_REFERENCE, it typically results in no reference field being defined for the dirfile, even if the dirfile contains RAW fields. As a result, functions which rely on the reference field, such as get_nframes(3), will operate incorrectly. Callers should explicitly set the reference field with dirfile_reference(3) in this case.SEE ALSO
dirfile_open(3), dirfile_parser_callback(3), dirfile_reference(3), dirfile_uninclude(3), get_error(3), get_error_string(3), get_fragmentname(3), get_nfragments(3), dirfile(5), dirfile-encoding(5), dirfile-format(5)