NAME

       sg_get_error,  sg_get_error_arg,  sg_get_error_errno,  sg_str_error, sg_get_error_details, sg_strperror -
       get last error status

SYNOPSIS

       #include <statgrab.h>

       sg_error sg_get_error (void);

       const char *sg_get_error_arg (void);

       int sg_get_error_errno (void);

       sg_error sg_get_error_details (sg_error_details *err_details);

       const char *sg_str_error (sg_error code);

       char *sg_strperror (char **buf, const sg_error_details * const err_details);

DESCRIPTION

       There are four functions to get information about  the  last  occurred  error:  sg_get_error,  sg_get_er‐
       ror_arg, sg_get_error_errno and sg_get_error_details. The remaining functions are intended to improve the
       machine-human-interface  (e.g.   the  error log or a message box): sg_str_error delivers a human readable
       error name and sg_strperror prepares a full blown error message for printing.

       The error argument (sg_get_error_arg) is stored thread local and is reused every time an  error  occures.
       If  a  later  usage  is intended, duplicating it is a suitable strategy. Same for the error_arg of sg_er‐
       ror_details delivered by sg_get_error_details.

       When someone calls the function sg_get_error_details with a NULL pointer, the last  error  is  overridden
       with a new one describing that sg_get_error_details is called with invalid arguments. Please be careful.

       The  function  sg_strperror is allowed to be called with or without (err_details is NULL) collected error
       details. In the latter case, the last occurred error of this thread is used to prepare the error message.
       Be aware, the the buffer pointer must be non-NULL (points to an existing char * lvalue), but the  char  *
       lvalue  it points to, must be NULL.  When invoked correctly, there are only two possible error conditions
       let sg_strperror fail: ENOMEM (out of memory) and EINVAL (invalid error code).

       Example

       if( NULL == sg_get_cpu_stats() ) {
           char *buf = NULL;
           if( NULL != sg_strperror( &buf, NULL ) ) {
               fprintf( stderr, "error getting CPU stats: %s\n", buf );
               free(buf);
               exit(255);
           }
           else {
               fprintf( stderr, "error getting CPU stats and error information\n" );
               exit(255);
           }
       }

RETURN VALUES

       The error details contains following information:

       typedef struct sg_error_details {
               sg_error error;
               int errno_value;
               const char *error_arg;
       } sg_error_details;

       error  The statgrab library error code.

       errno_value
              The operating system error code.

       error_arg
              Additional information set when the error was reported.

SEE ALSO

       statgrab(3)

WEBSITE

       ⟨https://libstatgrab.org/⟩

libstatgrab                                        2019-03-08                                    sg_get_error(3)