sg_get_error3

Usage

FC#include <statgrab.h>F[0]

Overview

There are four functions to get information about the last occurred error: FCsg_get_errorF[0], FCsg_get_error_argF[0], FCsg_get_error_errnoF[0] and FCsg_get_error_detailsF[0]. The remaining functions are intended to improve the machine-human-interface (e.g. the error log or a message box): FCsg_str_errorF[0] delivers a human readable error name and FCsg_strperrorF[0] prepares a full blown error message for printing.

The error argument (FCsg_get_error_argF[0]) 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 FCerror_argF[0] of FCsg_error_detailsF[0] delivered by FCsg_get_error_detailsF[0].

When someone calls the function FCsg_get_error_detailsF[0] with a NULL pointer, the last error is overridden with a new one describing that FCsg_get_error_detailsF[0] is called with invalid arguments. Please be careful.

The function FCsg_strperrorF[0] is allowed to be called with or without (FCerr_detailsF[0] 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 FCchar *F[0] lvalue), but the FCchar *F[0] lvalue it points to, must be NULL. When invoked correctly, there are only two possible error conditions let FCsg_strperrorF[0] fail: ENOMEM (out of memory) and EINVAL (invalid error code).

Example

FC
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);
    }
}
        F[0]

Return values

The error details contains following information:

FC
typedef struct sg_error_details {
        sg_error error;
        int errno_value;
        const char *error_arg;
} sg_error_details;
    F[0]

Website

⟨https://libstatgrab.org/⟩