source: vendor/current/lib/tdb/test/logging.c

#include "logging.h"
#include "tap-interface.h"
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>

bool suppress_logging = false;
const char *log_prefix = "";

/* Turn log messages into tap diag messages. */
static void taplog(struct tdb_context *tdb,
                   enum tdb_debug_level level,
                   const char *fmt, ...)
{
        va_list ap;
        char line[200];

        if (suppress_logging)
                return;

        va_start(ap, fmt);
        vsprintf(line, fmt, ap);
        va_end(ap);

        /* Strip trailing \n: diag adds it. */
        if (line[0] && line[strlen(line)-1] == '\n')
                diag("%s%.*s", log_prefix, (unsigned)strlen(line)-1, line);
        else
                diag("%s%s", log_prefix, line);
}

struct tdb_logging_context taplogctx = { taplog, NULL };