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.