| dafgn_c |
|
Table of contents
Procedure
dafgn_c ( DAF, get array name )
void dafgn_c ( SpiceInt namlen,
SpiceChar * name )
AbstractReturn (get) the name for the current array in the current DAF. Required_ReadingDAF KeywordsFILES Brief_I/OVARIABLE I/O DESCRIPTION -------- --- -------------------------------------------------- namlen I Length of array name string. name O Name of current array. Detailed_Input
namlen is the length of the `name' string, including room for the null
terminator. For a DAF with summary parameters ND and NI, the
maximum length of an array name is
(NI + 1)
NC = 8 * ( ND + -------- ) (Note that this is
2 integer division.)
Given NC, `namlen' should be set equal to NC+1.
Detailed_Output
name is the name for the current array (the array found by the
latest call to daffna_c or daffpa_c).
ParametersNone. Exceptions
1) If this routine is called when no search is in progress in the
current DAF, the error SPICE(DAFNOSEARCH) is signaled by a
routine in the call tree of this routine.
2) If the DAF for which the "current" array's name is to be
returned has actually been closed, an error is signaled by a
routine in the call tree of this routine.
3) If no array is current in the current DAF, the error
SPICE(NOCURRENTARRAY) is signaled by a routine in the call
tree of this routine. There is no current array when a search
is started by dafbfs_c or dafbbs_c, but no calls to daffna_c or
daffpa_c have been made yet, or whenever daffna_c or daffpa_c return
the value SPICEFALSE in the `found' argument.
4) If the `name' output string pointer is null, the error
SPICE(NULLPOINTER) is signaled.
5) If the `name' output string has length less than two
characters, the error SPICE(STRINGTOOSHORT) is signaled, since
the output string is too short to contain one character of
output data plus a null terminator.
FilesNone. Particulars
The DAF search routines are:
dafbfs_c Begin forward search.
daffna Find next array.
dafbbs_c Begin backward search.
daffpa_c Find previous array.
dafgs_c Get summary.
dafgn_c Get name.
dafgh_c Get handle.
dafcs_c Continue search.
The main function of these entry points is to allow the
contents of any DAF to be examined on an array-by-array
basis.
Conceptually, the arrays in a DAF form a doubly linked list,
which can be searched in either of two directions: forward or
backward. It is possible to search multiple DAFs simultaneously.
dafbfs_c (begin forward search) and daffna are used to search the
arrays in a DAF in forward order. In applications that search a
single DAF at a time, the normal usage is
dafbfs_c ( handle );
daffna_c ( &found );
while ( found )
{
dafgs_c ( sum );
dafgn_c ( name );
.
.
daffna_c ( &found );
}
dafbbs_c (begin backward search) and daffpa_c are used to search the
arrays in a DAF in backward order. In applications that search
a single DAF at a time, the normal usage is
dafbbs_c ( handle );
daffpa_c ( &found );
while ( found )
{
dafgs_c ( sum );
dafgn_c ( name );
.
.
daffpa_c ( &found );
}
In applications that conduct multiple searches simultaneously,
the above usage must be modified to specify the handle of the
file to operate on, in any case where the file may not be the
last one specified by dafbfs_c or dafbbs_c. The routine dafcs_c
(DAF, continue search) is used for this purpose. Below, we
give an example of an interleaved search of two files specified
by the handles handl1 and handl2. The directions of searches
in different DAFs are independent; here we conduct a forward
search on one file and a backward search on the other.
Throughout, we use dafcs to specify which file to operate on,
before calling daffna_c, daffpa_c, dafgs_c, or dafgn_c.
dafbfs_c ( handl1 );
dafbbs_c ( handl2 );
dafcs_c ( handl1 );
daffna_c ( &found1 );
dafcs_c ( handl2 );
daffpa_c ( &found2 );
while ( found1 || found2 )
{
if ( found1 )
{
dafcs_c ( handl1 );
dafgs_c ( sum );
dafgn_c ( name );
.
.
dafcs_c ( handl1 );
daffna_c ( &found1 );
}
if ( found2 )
{
dafcs_c ( handl2 );
dafgs_c ( sum );
dafgn_c ( name );
.
.
dafcs_c ( handl2 );
daffpa_c ( &found2 );
}
}
At any time, the latest array found (whether by daffna_c or daffpa_c)
is regarded as the "current" array for the file in which the
array was found. The last DAF in which a search was started,
executed, or continued by any of dafbfs_c, dafbbs_c, daffna_c,
daffpa_c or dafcs_c is regarded as the "current" DAF. The summary
and name for the current array in the current DAF can be obtained
separately, as shown above, by calls to dafgs_c (get summary) and
dafgn_c (get name). The handle of the current DAF can also be
obtained by calling dafgh_c (get handle).
Once a search has been begun, it may be continued in either
direction. That is, daffpa_c may be used to back up during a
forward search, and daffna_c may be used to advance during a
backward search.
Examples1) See -Particulars. RestrictionsNone. Literature_ReferencesNone. Author_and_InstitutionN.J. Bachman (JPL) J. Diaz del Rio (ODC Space) W.L. Taber (JPL) I.M. Underwood (JPL) Version
-CSPICE Version 1.1.0, 25-AUG-2021 (JDR)
Changed the input argument name "lenout" to "namlen" for consistency
with other routines.
Edited the header to comply with NAIF standard. Moved DAF required
reading from -Literature_References to -Required_Reading section.
Fixed typo in -Exceptions entry #3: daffpa_c is used to find the
previous array, not the non existing API dafbna_c.
-CSPICE Version 1.0.0, 01-AUG-1999 (NJB) (WLT) (IMU)
Index_Entriesget DAF array name |
Fri Dec 31 18:41:03 2021