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: http://www.stsci.edu/~sontag/spicedocs/cspice/getfat_c.html
Дата изменения: Sat Dec 17 06:09:05 2005 Дата индексирования: Mon Apr 11 00:02:49 2016 Кодировка: Поисковые слова: trees |
Determine the file architecture and file type of most SPICE kernel files.
None.
VARIABLE I/O DESCRIPTION -------- --- -------------------------------------------------- file I The name of a file to be examined. arclen I Maximum length of output architecture string. typlen I Maximum length of output type string. arch O The architecture of the kernel file. type O The type of the kernel file.
arclen is the maximum length of output architecture string arch, including the terminating null. For example, if arch is to hold strings having 10 characters of actual data, arclen should be set to 1l. typlen is the maximum length of output file type string type, including the terminating null. For example, if type is to hold strings having 10 characters of actual data, arclen should be set to 1l. file is the name of a SPICE kernel file whose architecture and type are desired. This file must be closed when this routine is called.
arch is the file architecture of the SPICE kernel file specified by file. If the architecture cannot be determined or is not recognized the value "?" is returned. Architectures currently recognized are: DAF - The file is based on the DAF architecture. DAS - The file is based on the DAS architecture. XFR - The file is in a SPICE transfer file format. DEC - The file is an old SPICE decimal text file. ASC -- An ASCII text file. KPL -- Kernel Pool File (i.e., a text kernel) TXT -- An ASCII text file. TE1 -- Text E-Kernel type 1. ? - The architecture could not be determined. This variable must be at least 3 characters long. type is the type of the SPICE kernel file. If the type can not be determined the value "?" is returned. Kernel file types may be any sequence of at most four printing characters. NAIF has reserved for its use types which contain all upper case letters. A file type of "PRE" means that the file is a pre-release file. This variable may be at most 4 characters long.
None.
This subroutine is a support utility routine that determines the architecture and type of a SPICE kernel file.
Suppose you wish to write a single routine for loading binary kernels. You can use this routine to determine the type of the file and then pass the file to the appropriate low level file loader to handle the actual loading of the file. getfat_c ( file, arch, type ); if ( eqstr_c( type, "spk" ) ) { spklef_c ( file, &handle ); } else if ( eqstr_c( type, "ck" ) ) { cklpf_c ( file, &handle ); } else if ( eqstr_c( type, "ek" ) ) { eklef ( file, handle ); } else { printf ( "%s\n", "The file could not be identified as aknown\n" "kernel type. Did you load the wrong file\n" "by mistake?" ); }
The file to be examined must be closed when this routine is invoked.
1) The underlying code translated to C from Fortran effectively performs a Fortran INQUIRE on the specified file. If this operation fails for some reason, the error SPICE(INQUIREERROR) will be signaled. 2) If the file specified by FILE is already open, the error SPICE(FILECURRENTLYOPEN) will be signaled. 3) If the file specified by FILE does not exist, the error SPICE(NOSUCHFILE) will be signaled. 4) If the attempt to open the file specified by FILE fails, the error SPICE(FILEOPENFAILED) will be signaled. 5) If all attempts to open the file specified by FILE fail, the error SPICE(FILEOPENFAILED) will be signaled. 6) If all attempts to read from the file specified be FILE fail, the error SPICE(FILEREADFAILED) will be signaled. 7) The error SPICE(EMPTYSTRING) is signaled if the input string does not contain at least one character, since the input string cannot be converted to a Fortran-style string in this case. 8) The error SPICE(NULLPOINTER) is signaled if the input string pointer is null. 9) If either output string pointer is null, the error SPICE(NULLPOINTER) is signaled. 10) If an output string has length less than two characters, it is too short to contain one character of output data plus a null terminator, so it cannot be passed to the underlying Fortran routine. In this event, the the error SPICE(STRINGTOOSHORT) is signaled.
The SPICE kernel file specified by FILE is opened and then closed by this routine to determine its file architecture and type. Names of open files should not be passed to this routine.
N.J. Bachman (JPL) K.R. Gehringer (JPL) H.A. Neilan (JPL) W.L. Taber (JPL)
None.
-CSPICE Version 1.0.0, 18-AUG-1998 (NJB)
determine the architecture and type of a kernel file