void qcktrc_c ( SpiceInt tracelen,
SpiceChar * trace )
Return a string containing a traceback.
ERROR
ERROR
VARIABLE I/O DESCRIPTION
-------- --- --------------------------------------------------
tracelen I Maximum length of output traceback string.
trace O A traceback string.
SPICE_ERROR_MAXMOD
P Maximum traceback module count.
SPICE_ERROR_MODLEN
P Maximum module name length.
SPICE_ERROR_TRCLEN
P Maximum length of output traceback string.
None.
trace is a list of module names, delimited by the string,
" --> ". An example would be
"SPUD --> SPAM --> FOOBAR".
The maximum length of the returned string is given
by the parameter SPICE_ERROR_TRCLEN. The value of this
parameter includes room for the terminating null.
In general, the meaning of the trace is as follows:
The first name in the list is the name of the first
module to check in (that hasn't yet checked out). The
last name is the name of the module at the end of the
call chain; this is the last module that checked in.
The meaning of the traceback depends on the state
of the error handling mechanism. There are two
cases:
1) In RETURN mode, when an error is signaled, the
traceback at that point is saved. trcdep_c,
trcnam_c, and qcktrc_c return values
pertaining to the saved traceback.
2) In all other modes, the traceback represents
the CURRENT call chain. trcdep_c, trcnam_c,
and qcktrc_c return values pertaining to the
current trace representation.
Any module names exceeding SPICE_ERROR_MODLEN
characters in length are truncated on the right.
The following parameters are declared in the header file SpiceErr.h:
SPICE_ERROR_MAXMOD is the maximum number of module names that can
be accommodated in the SPICE trace stack; this
is the maximum number of names that can appear
in the output traceback.
SPICE_ERROR_MODLEN is the maximum module name length that can be
accommodated by this routine.
SPICE_ERROR_TRCLEN is the maximum length of the string returned
by this routine. The value of this parameter
includes room for the terminating null.
1) If the output string pointer is null, the error SPICE(NULLPOINTER)
will be signaled.
2) If the output string has length less than 2 characters, the error
SPICE(STRINGTOOSHORT) will be signaled.
None.
This routine is part of the CSPICE error handling mechanism.
1) Deliberately generate a SPICE error to demonstrate use of
this routine together with trcnam_c. We'll attempt to look up
a state vector via spkezr_c without first having loaded any
SPK files.
Example code begins here.
#include <stdio.h>
#include "SpiceUsr.h"
int main()
{
/.
Local constants
./
#define ACTION "RETURN"
/.
Local variables
./
SpiceChar * abcorr;
SpiceChar trace [ SPICE_ERROR_TRCLEN ];
SpiceChar * obsrvr;
SpiceChar * frame;
SpiceChar * target;
SpiceDouble et;
SpiceDouble lt;
SpiceDouble state [6];
/.
Set error handling action to RETURN so that this program
won't terminate when a SPICE error is signaled. Note that
the input string length argument is unused for a "SET"
operation.
./
erract_c ( "SET", 0, ACTION );
/.
Generate a SPICE error: call spkezr_c without first having
loaded an SPK file.
./
et = 0.0;
target = "Moon";
obsrvr = "Earth";
frame = "J2000";
abcorr = "NONE";
spkezr_c ( target, et, frame, abcorr, obsrvr, state, < );
if ( failed_c() )
{
/.
An error has been signaled. Fetch and display
the traceback.
./
qcktrc_c ( SPICE_ERROR_TRCLEN, trace );
printf ( "Traceback: \n%s\n", trace );
/.
Reset the error status so that CSPICE can resume normal
operation.
./
reset_c();
}
return ( 0 );
}
When this program was executed on a PC/Linux/gcc platform, the
output (which has been reformatted to fit in the available
space in this header) was:
====================================================================
============
Toolkit version: N0065
SPICE(NOLOADEDFILES) --
At least one SPK file needs to be loaded by SPKLEF before beginning
a search.
A traceback follows. The name of the highest level module is first.
spkezr_c --> SPKEZR --> SPKEZ --> SPKGEO --> SPKSFS
====================================================================
============
Traceback:
spkezr_c --> SPKEZR --> SPKEZ --> SPKGEO --> SPKSFS
1) It is assumed no module names exceed SPICE_ERROR_MODLEN
characters in length.
None.
N.J. Bachman (JPL)
K.R. Gehringer (JPL)
-CSPICE Version 1.0.0, 05-NOV-2013 (NJB) (KRG)
get quick traceback
Link to routine qcktrc_c source file qcktrc_c.c
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