err.c

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>

#include "err.h"

/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

struct err {
    char *buf;
    size_t buf_size;
};

/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

err_t
err_create(size_t size)
{
    err_t err;

    err           = malloc(sizeof(*err));
    err->buf      = malloc(size);
    err->buf_size = size;

    err->buf[0] = '\0';

    return err;
}

void
err_destroy(err_t err)
{
    if (err != NULL) {
        if (err->buf != NULL) {
            free(err->buf);
        }

        free(err);
    }
}

void
err_set(
    err_t err,
    const char *filename,
    const char *functionname,
    const int linenum,
    const char *format,
    ...
) {
    char buf1[256]; /* XXX should not be fixed size */
    va_list ap;

    va_start(ap, format);
    vsnprintf(buf1, sizeof(buf1), format, ap);
    va_end(ap);

    snprintf(
        err->buf,
        err->buf_size,
        "%s, %s(), line %d: %s",
        filename, functionname, linenum, buf1
    );
}

const char *
err_get(err_t err)
{
    return (const char *)(err->buf);
}