afSetErrorHandler(3dm)afSetErrorHandler(3dm)NAMEafSetErrorHandler - supply an alternate error reporting routine to the
Audio File Library
SYNOPSIS
#include <dmedia/audiofile.h>
AFerrfunc afSetErrorHandler(AFerrfunc efunc)
PARAMETER
efunc is a pointer to an error handling routine which is declared
as:
void errorfunc(long, const char*)
RETURNED VALUE
The returned value is a pointer to the previous error handling routine.
DESCRIPTIONafSetErrorHandler() allows you to override the default error handling
routine.
The arguments that are passed to the error handling routine are an error
code and a string containing a description of the error.
EXAMPLE
#include <dmedia/audiofile.h>
AFerrfunc defaultErrorHandler;
void silentAFerror(long errnum, const char* fmt)
{
/* suppress AF errors here */
}
...
/* supply a new error handler */
defaultErrorHandler = afSetErrorHandler(silentAFerror);
/* AF errors won't be reported here */
...
/* restore the default error handler */
afSetErrorHandler(originalErrorHandler);
/* AF errors will be reported by the default error handler */
...
CAVEATS
The AF library error handler function pointer is declared as a global
variable, and therefor is not safe for use in multi-threaded
applications. Specifically, a core dump may result if more than one
thread attempts to use the error handler simultaneously. This can be
avoided by calling afSetErrorHandler(NULL) to disable the feature
entirely. The current version of the AF library has a MT-safe
alternative to the AFerrorhandler:
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afSetErrorHandler(3dm)afSetErrorHandler(3dm)
After disabling the internal error handler as shown above, an application
should handle errors as in the example below:
#include <dmedia/dmedia.h>
AFfilehandle handle;
handle = afOpenFile("some_filename", "r", NULL); /* attempt to open */
if(handle == NULL) {
char detail[DM_MAX_ERROR_DETAIL]; /* storage for error detail */
int errorNumber; /* error token storage */
char *msg; /* short error message */
msg = dmGetError(&errorNumber, detail);
if(msg != NULL) /* if NULL, no error was reported */
fprintf(stderr, "%s [error number %d]\n", detail, errorNumber);
exit(1); /* or whatever */
}
The application must add -ldmedia to its link list if it calls
dmGetError(). See dmGetError(3dm) for more details on this alternative.
SEE ALSOstdarg(5), afIntro(3dm), dmIntro(3dm), dmGetError(3dm)
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