comedi_strerror — return string describing Comedilib error code


#include <comedilib.h>
const char * comedi_strerror(int errnum);


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 or 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 returned string may be modified by a subsequent call to a strerr or perror function (either the libc or Comedilib versions). An unrecognized error number will return a pointer to the string undefined error, or similar.