NAME
comedi_strerror - return string describing Comedilib error code
SYNOPSIS
#include <comedilib.h>
char * comedi_strerror (int errnum);
DESCRIPTION
When a Comedilib function fails, it usually returns -1 or NULL,
depending on the return type. An internal library variable stores an
error number, which can be retrieved with comedi_errno(). This error
number can be converted to a human-readable form by the functions
comedi_perror() and comedi_strerror().
These functions are intended to mimic the behavior of the standard C
library functions perror(), strerror(), and errno. In particular,
Comedilib functions sometimes return an error that is generated inside
the C library; the comedi error message in this case is the same as the
C library.
The function comedi_strerror() returns a pointer to a character string
describing the Comedilib error errnum. The persistence of the returned
pointer is undefined, and should not be trusted after the next
Comedilib call. An unrecognized error number will return a pointer to
the string "undefined error", or similar.
28 October 2007